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1
Fox, A. J., and A. P. R. Cooper. "Climate-change indicators from archival aerial photography of the Antarctic Peninsula." Annals of Glaciology 27 (1998): 636–42. http://dx.doi.org/10.3189/1998aog27-1-636-642.
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Aerial photography has been used as a mapping tool in the Antarctic Peninsula region sinre the late 1920s. Following pioneering work by Wilkins in 1928, Ellsworth in 1934 and the British Graham Land Expedition in 1934-37, the Falkland Islands and Dependencies Aerial Survey Expedition carried out extensive aerial photography during the period 1955-57. Since then, many other aerial surveys have been carried out, and the result is an archive of aerial photography that, for some localities, spans 40 years. The production of maps both from different generations of photographs and satellite images has revealed many changes in the extent of ice cover with time. For example, changes in ice shelves such as the Wordie Ice Shelf, Larsen Ice Shelf and Müller Ice Shelf, are well recorded, and the termini of some glaciers have retreated. However, the most pervasive change is the consistent decline in the extent of small bodies of snow and ice. This paper shows how perennial snow or ice cover has decreased in the northern Marguerite Bay area, at 68°S. The correlation of the change with elevation and with climate records from Adelaide and Rothera research stations in the Antarctic Peninsula region is examined.
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Baroni, Carlo, Massimo Frezzotti, Maria Cristina Salvatore, Mirco Meneghel, Ignazio E. Tabacco, Luca Vittuari, Aldino Bondesan, Alessandro Biasini, Alessandro Cimbelli, and Giuseppe Orombelli. "Antarctic geomorphological and glaciological 1 : 250 000 map series: Mount Murchison quadrangle, northern Victoria Land. Explanatory notes." Annals of Glaciology 39 (2004): 256–64. http://dx.doi.org/10.3189/172756404781814131.
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AbstractGeomorphological and glaciological features are represented on a georeferenced satellite image mosaic of the Mount Murchison quadrangle, northern Victoria Land, Antarctica (73–74˚ S, 162–166˚30' E), at a scale of 1 : 250 000. Landforms and deposits of glacial and periglacial environments, forms related to mass wasting, wind action, weathering and geological structures are identified and mapped. The chronological sequence of landforms and deposits, morphography and lithology is also indicated. Glacier velocities (up to 180 ma–1) and ice-front fluctuations (1964–99) were determined by analysis of aerial photography and satellite imagery. Airborne radar surveys reveal that the greatest ice thickness (about 1500 m) is located in the grounding zone of Aviator Glacier. Up to 1000 mof ice bury the subglacial relief of Deception Plateau, Hercules Névé and the Deep Freeze Range. Snow accumulation rates (average = 170 kg m–2 a–1) exhibit an overall negative correlation with altitude and distance from the coast. The relationships among relict erosional landforms and volcanic activity provide chronological constraints for the palaeogeographic evolution of this sector of the Transantarctic Mountains.
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Fraser, R. H., I. Olthof, M. Maloley, R. Fernandes, C. Prevost, and J. van der Sluijs. "UAV PHOTOGRAMMETRY FOR MAPPING AND MONITORING OF NORTHERN PERMAFROST LANDSCAPES." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL-1/W4 (August 27, 2015): 361. http://dx.doi.org/10.5194/isprsarchives-xl-1-w4-361-2015.
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Northern environments are changing in response to recent climate warming, resource development, and natural disturbances. The Arctic climate has warmed by 2–3°C since the 1950’s, causing a range of cryospheric changes including declines in sea ice extent, snow cover duration, and glacier mass, and warming permafrost. The terrestrial Arctic has also undergone significant temperature-driven changes in the form of increased thermokarst, larger tundra fires, and enhanced shrub growth. Monitoring these changes to inform land managers and decision makers is challenging due to the vast spatial extents involved and difficult access. <br><br> Environmental monitoring in Canada’s North is often based on local-scale measurements derived from aerial reconnaissance and photography, and ecological, hydrologic, and geologic sampling and surveying. Satellite remote sensing can provide a complementary tool for more spatially comprehensive monitoring but at coarser spatial resolutions. Satellite remote sensing has been used to map Arctic landscape changes related to vegetation productivity, lake expansion and drainage, glacier retreat, thermokarst, and wildfire activity. However, a current limitation with existing satellite-based techniques is the measurement gap between field measurements and high resolution satellite imagery. Bridging this gap is important for scaling up field measurements to landscape levels, and validating and calibrating satellite-based analyses. This gap can be filled to a certain extent using helicopter or fixed-wing aerial surveys, but at a cost that is often prohibitive. <br><br> Unmanned aerial vehicle (UAV) technology has only recently progressed to the point where it can provide an inexpensive and efficient means of capturing imagery at this middle scale of measurement with detail that is adequate to interpret Arctic vegetation (i.e. 1–5 cm) and coverage that can be directly related to satellite imagery (1–10 km<sup>2</sup>). Unlike satellite measurements, UAVs permit frequent surveys (e.g. for monitoring vegetation phenology, fires, and hydrology), are not constrained by repeat cycle or cloud cover, can be rapidly deployed following a significant event, and are better suited than manned aircraft for mapping small areas. UAVs are becoming more common for agriculture, law enforcement, and marketing, but their use in the Arctic is still rare and represents untapped technology for northern mapping, monitoring, and environmental research. <br><br> We are conducting surveys over a range of sensitive or changing northern landscapes using a variety of UAV multicopter platforms and small sensors. Survey targets include retrogressive thaw slumps, tundra shrub vegetation, recently burned vegetation, road infrastructure, and snow. Working with scientific partners involved in northern monitoring programs (NWT CIMP, CHARS, NASA ABOVE, NRCan-GSC) we are investigating the advantages, challenges, and best practices for acquiring high resolution imagery from multicopters to create detailed orthomosaics and co-registered 3D terrain models. Colour and multispectral orthomosaics are being integrated with field measurements and satellite imagery to conduct spatial scaling of environmental parameters. Highly detailed digital terrain models derived using structure from motion (SfM) photogrammetry are being applied to measure thaw slump morphology and change, snow depth, tundra vegetation structure, and surface condition of road infrastructure. <br><br> These surveys and monitoring applications demonstrate that UAV-based photogrammetry is poised to make a rapid contribution to a wide range of northern monitoring and research applications.
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Kerbes, Richard H., Katherine M. Meeres, James E. Hines, and David G. Kay. "Lesser Snow Geese, Chen caerulescens caerulescens, and Ross's Geese, Chen rossii, of Jenny Lind Island, Nunavut." Canadian Field-Naturalist 122, no. 1 (January 1, 2008): 34. http://dx.doi.org/10.22621/cfn.v122i1.540.
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We surveyed the Lesser Snow (Chen caerulescens caerulescens) and Ross’s geese (Chen rossii) of Jenny Lind Island, Nunavut, using aerial photography in June 1988, 1998, and 2006, and a visual helicopter transect survey in July 1990. The estimated number of nesting geese was 39 154 ± SE 2238 in 1988, 19 253 ± 2323 in 1998, and 21 572 ± 1898 in 2006. In 1988 an estimated 2.7% of the nesting geese were Ross’s. The July 1990 population of adult-plumaged birds was 25 020 ± 3114. The estimated percentage blue morph among Snow and Ross’s geese was 19.0% in 1988, 25.1% in 1989, 23.0% in 1990 and 21.1% in 2006. Estimated pre-fledged Snow Goose productivity was 47% young in 1989 and 46% in 1990. Combined numbers of Snow and Ross’s geese on Jenny Lind Island grew over 250 fold, from 210 adults in 1962-1966 to 54 100 adults in 1985. Numbers subsequently declined, to 42 200 in 1988, 25 000 in 1990, 20 300 in 1998, and 26 400 in 2006. Population decline between 1985 and 1990 was consistent with anecdotal reports by others that die-offs of Snow Geese occurred in 1984, 1985 and 1989, and with our August 1989 fieldwork which found evidence of habitat degradation and malnourishment of young geese. In spite of limited food resources on Jenny Lind Island, the colony continued to exist in 2006 at near its 1990 and 1998 levels. Further studies there could provide insights for management of the overabundant mid-continent Snow Goose population and its arctic habitats.
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Lendzioch, Theodora, Jakub Langhammer, and Michal Jenicek. "Estimating Snow Depth and Leaf Area Index Based on UAV Digital Photogrammetry." Sensors 19, no. 5 (February 28, 2019): 1027. http://dx.doi.org/10.3390/s19051027.
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This study presents a novel approach in the application of Unmanned Aerial Vehicle (UAV) imaging for the conjoint assessment of the snow depth and winter leaf area index (LAI), a structural property of vegetation, affecting the snow accumulation and snowmelt. The snow depth estimation, based on a multi-temporal set of high-resolution digital surface models (DSMs) of snow-free and of snow-covered conditions, taken in a partially healthy to insect-induced Norway spruce forest and meadow coverage area within the Šumava National Park (Šumava NP) in the Czech Republic, was assessed over a winter season. The UAV-derived DSMs featured a resolution of 0.73–1.98 cm/pix. By subtracting the DSMs, the snow depth was determined and compared with manual snow probes taken at ground control point (GCP) positions, the root mean square error (RMSE) ranged between 0.08 m and 0.15 m. A comparative analysis of UAV-based snow depth with a denser network of arranged manual snow depth measurements yielded an RMSE between 0.16 m and 0.32 m. LAI assessment, crucial for correct interpretation of the snow depth distribution in forested areas, was based on downward-looking UAV images taken in the forest regime. To identify the canopy characteristics from downward-looking UAV images, the snow background was used instead of the sky fraction. Two conventional methods for the effective winter LAI retrieval, the LAI-2200 plant canopy analyzer, and digital hemispherical photography (DHP) were used as a reference. Apparent was the effect of canopy density and ground properties on the accuracy of DSMs assessment based on UAV imaging when compared to the field survey. The results of UAV-based LAI values provided estimates were comparable to values derived from the LAI-2200 plant canopy analyzer and DHP. Comparison with the conventional survey indicated that spring snow depth was overestimated, and spring LAI was underestimated by using UAV photogrammetry method. Since the snow depth and the LAI parameters are essential for snowpack studies, this combined method here will be of great value in the future to simplify snow depth and LAI assessment of snow dynamics.
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Hu, Jianbo, Xiaomin Wu, and Mingxing Dai. "Estimating the population size of migrating Tibetan antelopes Pantholops hodgsonii with unmanned aerial vehicles." Oryx 54, no. 1 (April 26, 2018): 101–9. http://dx.doi.org/10.1017/s0030605317001673.
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AbstractData on the distribution and population size of the Near Threatened Tibetan antelope Pantholops hodgsonii are necessary to protect this species. Ground-based count surveys are usually carried out from a long distance to avoid disturbing the sensitive animals, and on calving grounds or along migration routes where they are seasonally concentrated. This can result in underestimation of population sizes if terrain features obstruct the view and high concentrations of animals make estimating numbers difficult. Here we test the efficacy of unmanned aerial vehicles (UAVs) for gathering population data for the Tibetan antelope. We conducted the study south of a known calving ground, at the foot of Sewu Snow Mountain, in the Chang Tang National Nature Reserve, China. The UAV did not appear to disturb the animals and resulted in more accurate counts than ground-based observations. A total of 23,063 Tibetan antelopes were identified in twelve orthoimages derived from c. 4,000 aerial photographs. In the first flight area 7,671 females and 4,353 calves were identified (proportion of calves: 36.2%). In the second flight area 7,989 females and 3,050 calves were identified (proportion of calves: 27.6%). Two flights over the same area revealed the direction and speed of moving Tibetan antelope groups. Image resolution, which can be controlled with flight planning, was an important factor in determining the animals’ visibility in the photos. We found that UAV-based surveys outperformed ground-based surveys, and that larger UAVs are preferable for this application.
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Knizhnikov, Yu F., V. I. Kravtsova, and I. A. Labutina. "Cartographic Remote-Sensing Monitoring of Glaciological Systems (Example, Mount El‛ Brus, U.S.S.R.) (Abstract)." Annals of Glaciology 9 (1987): 247–48. http://dx.doi.org/10.3189/s0260305500000872.
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Remote-sensing methods in monitoring the glacierization of Mount EI‛ brus are used to produce base and dynamic maps, and to obtain quantitative information (dynamic indices) about the rate, intensity, and variations of the process. The monitoring system is divided, according to scope and territory covered, into small-scale for total glacierization and the periglacial zone, medium-scale for separate glaciers, and large-scale (detailed) for part of the glaciers or sectors of the adjoining slopes. The approximate relationship of even scales is 1 : 4.Small-scale monitoring remote-sensing systems are important for making maps showing the complex characteristics of the glaciological system. A series of maps was produced including geographical, those of high-altitude zones, slope and exposure angles, geological, glaciomorphological, climatic (temperature, precipitation, and winds), distribution of direct solar radiation, hydrological (source of streams), seats of avalanches, and landslides. All these data serve as a cartographical basis in monitoring the glacierization of Mount EI‛ brus. They are compiled from remotely sensed and Earth-based data.Current monitoring on a small scale includes observations of the conditions which determine the existence of the glacial system - this includes data on winter snowfall and the period of snow cover. These observations were obtained from meteorological and resource satellites, and from scanner data of medium and high resolution. Also important are observations of changes in the outline of glaciers, times of snowfall and character of the distribution of snow, and its redistribution due to avalanches and snowstorms. High-resolution space photographs, small-scale aerial photographs, and aerovisual observations provide the data for these observations. It has been determined that the area of the glaciers of Mount El‛ brus has been reduced by 1 % in the last 25 years, i.e. the rate of its deglacierization dropped sharply as compared to preceding decades.The role of quantitative information gains importance in the medium-scale level of monitoring. Topographical maps of separate glaciers compiled from aerial photographs or data from ground stereo-photogrammetric surveys constitute the base maps at this level. The main method used in monitoring were large-scale surveys from aircraft, perspective surveys from helicopters, and phototheodolite surveys. Multi-date surveys of the glaciers provide data about the changes in their outlines and height, the character of their relief, their moraines, the amount of snow accumulation and ablation in separate years, the surface rates of ice flow and their fluctuations. The techniques by which quantitative information is obtained about changes in the glaciers are derived from processing the data of multi-date surveys. The organization and techniques of phototheodolite surveys have been improved. A theory evolved for determining the surface-ice movement by stereo-photogrammetric means and the technique for it has also improved; algorithms and programs for machine processing of the data of multi-date surveys (ground and from aircraft) have been producedAt this level of monitoring, it has been found that the retreat rate of most glaciers has slowed down and several glaciers are now in equilibrium. Several glaciers became active at the beginning of the 1970s and 1980s; this was accompanied by an increase in their height and forward movement. For example, activation of Kyukyurtlyu Glacier has been recorded (higher surface and increasing flow rate) which has caused the glacier to move forward 100 m. Surveys at an interval of 2 years recorded the beginning of the process of retreat of this glacier.Detailed monitoring is used to detect the mechanism of the dynamic processes and to study it on local representative sectors. On a glacier it may take the form of annual surveys of its tongue, which makes it possible to observe the processes of formation of moraines and glacio-fluvial relief. Studies may also be made of the mechanism of the movement of avalanches and landslides, deducing their quantitative characteristics and appraising the results of avalanches and landslides. Multi-date surveys of sectors of the slopes provide information about processes in the periglacial zone. At this level, regularly repeated ground stereo-photogrammetric surveys are the main means of observation.Glaciological remote-sensing monitoring provides a wealth of data for theoretical development in the field of glaciology. It makes it possible to forecast and produce warnings about hazardous processes and phenomena.
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Knizhnikov, Yu F., V. I. Kravtsova, and I. A. Labutina. "Cartographic Remote-Sensing Monitoring of Glaciological Systems (Example, Mount El‛ Brus, U.S.S.R.) (Abstract)." Annals of Glaciology 9 (1987): 247–48. http://dx.doi.org/10.1017/s0260305500000872.
Full textAbstract:
Remote-sensing methods in monitoring the glacierization of Mount EI‛ brus are used to produce base and dynamic maps, and to obtain quantitative information (dynamic indices) about the rate, intensity, and variations of the process. The monitoring system is divided, according to scope and territory covered, into small-scale for total glacierization and the periglacial zone, medium-scale for separate glaciers, and large-scale (detailed) for part of the glaciers or sectors of the adjoining slopes. The approximate relationship of even scales is 1 : 4. Small-scale monitoring remote-sensing systems are important for making maps showing the complex characteristics of the glaciological system. A series of maps was produced including geographical, those of high-altitude zones, slope and exposure angles, geological, glaciomorphological, climatic (temperature, precipitation, and winds), distribution of direct solar radiation, hydrological (source of streams), seats of avalanches, and landslides. All these data serve as a cartographical basis in monitoring the glacierization of Mount EI‛ brus. They are compiled from remotely sensed and Earth-based data. Current monitoring on a small scale includes observations of the conditions which determine the existence of the glacial system - this includes data on winter snowfall and the period of snow cover. These observations were obtained from meteorological and resource satellites, and from scanner data of medium and high resolution. Also important are observations of changes in the outline of glaciers, times of snowfall and character of the distribution of snow, and its redistribution due to avalanches and snowstorms. High-resolution space photographs, small-scale aerial photographs, and aerovisual observations provide the data for these observations. It has been determined that the area of the glaciers of Mount El‛ brus has been reduced by 1 % in the last 25 years, i.e. the rate of its deglacierization dropped sharply as compared to preceding decades. The role of quantitative information gains importance in the medium-scale level of monitoring. Topographical maps of separate glaciers compiled from aerial photographs or data from ground stereo-photogrammetric surveys constitute the base maps at this level. The main method used in monitoring were large-scale surveys from aircraft, perspective surveys from helicopters, and phototheodolite surveys. Multi-date surveys of the glaciers provide data about the changes in their outlines and height, the character of their relief, their moraines, the amount of snow accumulation and ablation in separate years, the surface rates of ice flow and their fluctuations. The techniques by which quantitative information is obtained about changes in the glaciers are derived from processing the data of multi-date surveys. The organization and techniques of phototheodolite surveys have been improved. A theory evolved for determining the surface-ice movement by stereo-photogrammetric means and the technique for it has also improved; algorithms and programs for machine processing of the data of multi-date surveys (ground and from aircraft) have been produced At this level of monitoring, it has been found that the retreat rate of most glaciers has slowed down and several glaciers are now in equilibrium. Several glaciers became active at the beginning of the 1970s and 1980s; this was accompanied by an increase in their height and forward movement. For example, activation of Kyukyurtlyu Glacier has been recorded (higher surface and increasing flow rate) which has caused the glacier to move forward 100 m. Surveys at an interval of 2 years recorded the beginning of the process of retreat of this glacier. Detailed monitoring is used to detect the mechanism of the dynamic processes and to study it on local representative sectors. On a glacier it may take the form of annual surveys of its tongue, which makes it possible to observe the processes of formation of moraines and glacio-fluvial relief. Studies may also be made of the mechanism of the movement of avalanches and landslides, deducing their quantitative characteristics and appraising the results of avalanches and landslides. Multi-date surveys of sectors of the slopes provide information about processes in the periglacial zone. At this level, regularly repeated ground stereo-photogrammetric surveys are the main means of observation. Glaciological remote-sensing monitoring provides a wealth of data for theoretical development in the field of glaciology. It makes it possible to forecast and produce warnings about hazardous processes and phenomena.
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Babashkin, N. M., S. A. Kadnichanskiy, Yu I. Kuchinskiy, and S. S. Nekhin. "Choosing Aerial Photography Parametres For Modern Aerial Topographic Surveys." Geodesy and Cartography 870, no. 13 (December 31, 2012): 161–64. http://dx.doi.org/10.22389/0016-7126-2012-161-164.
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Burshtynska, Khrystyna, Andrzej Mazur, Maksym Halochkin, Yevhenii Shylo, and Iryna Zayats. "GEODESY, CARTOGRAPHY AND AERIAL PHOTOGRAPHY." GEODESY, CARTOGRAPHY AND AERIAL PHOTOGRAPHY 95,2022, no. 95 (June 28, 2022): 53–64. http://dx.doi.org/10.23939/istcgcap2022.95.053.
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The aim of the work is to investigate the accuracy of the DEM of nearshore areas using UAV material. One of the important issues in hydrological flood modelling is the high accuracy of the DEM. In the case of a complex relief type, which is associated with meandering riverbeds, it is proposed to use UAV surveys to create a DEM. Hydrological modelling involves the following main steps: creation of high precision DEMs, determination of Manning coefficients to account for the influence of the underlying surface and determination of water level changes based on the water level graph derived from observations at hydrometeorological stations. This research presents the construction of a high-precision DEM, based on a UAV survey. For high-precision modeling, the fundamental issue is the consideration of vegetation in the nearshore areas and the choice of the optimal time period for the survey. The aim of the study is to develop a methodology for the construction of a high-precision DEM from UAV data, investigate the possibilities of eliminating the influence of vegetation on point marks using software methods, determine planned channel shifts and compare the accuracy of DEM construction for surveys conducted in June 2017 and in November 2021. The section at the transition from the mountainous to marshy-hilly part of the Dniester River near the town of Stary Sambir, with complex morphometric and hydrological characteristics of the channel and banks at the site of the complex meandering of the river in a rugged ravine area was the study object of this work. Results. It was found that for 4 years between two surveys, the planned displacements of some points are up to 25-31 meters. A priori estimation of coordinates determination by points from the GNSS-receiver was carried out, the accuracy of point coordinates determination is 2-3 cm. The a priori estimate of the accuracy of determining the coordinates of points from the input survey data is: for plan coordinates - 4-6 cm for two survey periods, the error in determining the marks of points for different values of the baseline - 21-31 cm. It has been established, that the program methods of accounting of influence of high vegetation do not give the possibility of its full accounting, the average square error, in places of such vegetation makes 0,64 m. Therefore, it is necessary to carry out UAV survey in the leafless period of the year, early spring or late autumn. Scientific novelty consists in the study of the possibility of constructing a high-precision DEM for different types of vegetation from materials obtained from UAVs. The results can be used for hydrological modeling of river channels with complex hydromorphological characteristics.
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Pisetskaya, Olga, Yanina Isayeva, and Maksim Goutsaki. "Application of Unmanned Flying Vehicle for Obtaining Digital Orthofotomaps." Baltic Surveying 11 (November 20, 2019): 60–69. http://dx.doi.org/10.22616/j.balticsurveying.2019.018.
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Nowadays, surveys using unmanned aerial vehicles is becoming popular. The resulting orthophotomap is the final product for creating digital plans and cardboard. The objectives of the study are to study the possibilities of obtaining orthophotomaps from survey materials using unmanned aerial vehicles based on the results of the experiment. The article describes various types of aerial photography. Some types of unmanned flying vehicles to conduct aerial photography for the purpose of monitoring, engineering surveys, inventory of agricultural land, and crop forecasts are considered. A description of aerial photography surveying is given on the example of the city of Dzerzhinsk, Minsk Region, which is performed taking into account the unmanned flying vehicles of GeoScan 201 and the Republican agricultural aero-geodesic unitary enterprise BelPSHAGI. A description of the GeoScan Planner software and basic pre-flight preparation is given. The stages of the preparatory work before the aerial photography, the creation of the planning and high-altitude geodetic justification, the implementation of aerial photography procedures, the steps of the aerial photograph anchorage procedure are considered. Agisoft Photoscan, which allows to get clouds of points, surfaces, 3D models and orthophotomaps using digital raster images are presented. The map of heights (DEM) of the terrain and the orthophotomap was made on the basis of a dense points cloud. According to the results of the research, a conclusion was made on the possibility of using aerial photography materials obtained using unmanned flying vehicles to get orthophotomaps of the required accuracy.
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Amos, E. M., D. Blakeway, and C. D. Warren. "Remote Sensing Techniques in Civil Engineering Surveys." Geological Society, London, Engineering Geology Special Publications 2, no. 1 (1986): 119–24. http://dx.doi.org/10.1144/gsl.1986.002.01.26.
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AbstractThis paper outlines selected remote sensing techniques and their application to civil engineering surveys.In BS 5930, emphasis has been placed on the interpretation of black and white aerial photography to provide information. However, other techniques such as true colour and false colour infrared photography, thermal infrared, radar and landsat satellite imagery may be useful in appropriate applications.
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Kuznetsov, Evgeniy, Galina Koretskaia, and Asmelash Abay. "Comparative Analysis of Aerial Photography with Instrumental Survey." E3S Web of Conferences 174 (2020): 01031. http://dx.doi.org/10.1051/e3sconf/202017401031.
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At present, in Kuzbass, various methods of automation of plane surveys in open mining are used. In most cases, the choice of method depends on the material base of the enterprise and the professionalism of the performers. Typically, the work on the surveying automation consists in using electronic tachometers, which reduce time and simplify field and office work. However, the use of electronic tachometers remains the human factor and does not allow solving the problem of displaying the situation throughout the open pit at one physical moment of time. Aerial photography (AP) significantly increases the performance of plane surveys and makes it possible to most fully and reliably display the information about the surface and ensure the safety of fieldwork. The article presents a comparative analysis of the accuracy of constructing a digital terrain model obtained during aerial photography by AN-2 aircraft and instrumental survey performed with electronic tachometer Leica TS 06 plus, by example of surveying a trench of section № 1 at Olzherassky open pit in the Kemerovo region. The advantages and disadvantages of AP from an airplane and prospects of using AP from an unmanned aerial vehicle (UAV) are given.
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Rybchenko, A. A., A. V. Kadetova, E. A. Kozyreva, and A. A. Yuriev. "Experience of using non‐specialized unmanned aerial vehicles for aerial surveys in the studies of exogenous geological processes." Geodynamics & Tectonophysics 10, no. 4 (December 11, 2019): 1045–58. http://dx.doi.org/10.5800/gt-2019-10-4-0457.
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The article reviews the experience of aerial surveys using a quadcopter DJI Inspire 1 PRO (unmanned aerial vehicle, UAV) for solving problems of engineering geodynamics. It describes the application of photogrammetry to estimate quantitative parameters of the studied objects, the experience of using UAVs to study flood processes in the Tunka valley (Russia) and erosion structures in the Ulaanbaatar agglomeration (Mongolia). The first UAV‐acquired data on debris flow alluvial fans and elementary drainage basins of erosion structures are presented. The ranges of UAV flight heights were 100–150 m and 1–30 m for local and detailed aerial photography surveys, respectively. Local surveys covered relatively large objects – debris flow alluvial fans and drainage basins. Detailed aerial photography aimed to investigate the granulometric compositions of debris flow deposits and to construct transverse profiles of erosion structures. Processed aerial photos provided a basis for a schematic map showing the distribution of accumu‐ lated debris flow deposits. The granulometric compositions of coarse fractions in the debris flow deposits were de‐ termined. Based on the survey results, 3D models of the fragments of the erosion structures and their cross‐sections were constructed.
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Lendzioch, T., J. Langhammer, and M. Jenicek. "TRACKING FOREST AND OPEN AREA EFFECTS ON SNOW ACCUMULATION BY UNMANNED AERIAL VEHICLE PHOTOGRAMMETRY." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B1 (June 6, 2016): 917–23. http://dx.doi.org/10.5194/isprs-archives-xli-b1-917-2016.
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Airborne digital photogrammetry is undergoing a renaissance. The availability of low-cost Unmanned Aerial Vehicle (UAV) platforms well adopted for digital photography and progress in software development now gives rise to apply this technique to different areas of research. Especially in determining snow depth spatial distributions, where repetitive mapping of cryosphere dynamics is crucial. Here, we introduce UAV-based digital photogrammetry as a rapid and robust approach for evaluating snow accumulation over small local areas (e.g., dead forest, open areas) and to reveal impacts related to changes in forest and snowpack. Due to the advancement of the technique, snow depth of selected study areas such as of healthy forest, disturbed forest, succession, dead forest, and of open areas can be estimated at a 1 cm spatial resolution. The approach is performed in two steps: 1) developing a high resolution Digital Elevation Model during snow-free and 2) during snow-covered conditions. By substracting these two models the snow depth can be accurately retrieved and volumetric changes of snow depth distribution can be achieved. This is a first proof-of-concept study combining snow depth determination and Leaf Area Index (LAI) retrieval to monitor the impact of forest canopy metrics on snow accumulation in coniferous forest within the Šumava National Park, Czech Republic. Both, downward-looking UAV images and upward-looking LAI-2200 canopy analyser measurements were applied to reveal the LAI, controlling interception and transmitting radiation. For the performance of downward-looking images the snow background instead of the sky fraction was used. In contrast to the classical determination of LAI by hemispherical photography or by LAI plant canopy analyser, our approach will also test the accuracy of LAI measurements by UAV that are taken simultaneously during the snow cover mapping campaigns. Since the LAI parameter is important for snowpack modelling, this method presents the potential of simplifying LAI retrieval and mapping of snow dynamics while reducing running costs and time.
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Lendzioch, T., J. Langhammer, and M. Jenicek. "TRACKING FOREST AND OPEN AREA EFFECTS ON SNOW ACCUMULATION BY UNMANNED AERIAL VEHICLE PHOTOGRAMMETRY." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B1 (June 6, 2016): 917–23. http://dx.doi.org/10.5194/isprsarchives-xli-b1-917-2016.
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Airborne digital photogrammetry is undergoing a renaissance. The availability of low-cost Unmanned Aerial Vehicle (UAV) platforms well adopted for digital photography and progress in software development now gives rise to apply this technique to different areas of research. Especially in determining snow depth spatial distributions, where repetitive mapping of cryosphere dynamics is crucial. Here, we introduce UAV-based digital photogrammetry as a rapid and robust approach for evaluating snow accumulation over small local areas (e.g., dead forest, open areas) and to reveal impacts related to changes in forest and snowpack. Due to the advancement of the technique, snow depth of selected study areas such as of healthy forest, disturbed forest, succession, dead forest, and of open areas can be estimated at a 1 cm spatial resolution. The approach is performed in two steps: 1) developing a high resolution Digital Elevation Model during snow-free and 2) during snow-covered conditions. By substracting these two models the snow depth can be accurately retrieved and volumetric changes of snow depth distribution can be achieved. This is a first proof-of-concept study combining snow depth determination and Leaf Area Index (LAI) retrieval to monitor the impact of forest canopy metrics on snow accumulation in coniferous forest within the Šumava National Park, Czech Republic. Both, downward-looking UAV images and upward-looking LAI-2200 canopy analyser measurements were applied to reveal the LAI, controlling interception and transmitting radiation. For the performance of downward-looking images the snow background instead of the sky fraction was used. In contrast to the classical determination of LAI by hemispherical photography or by LAI plant canopy analyser, our approach will also test the accuracy of LAI measurements by UAV that are taken simultaneously during the snow cover mapping campaigns. Since the LAI parameter is important for snowpack modelling, this method presents the potential of simplifying LAI retrieval and mapping of snow dynamics while reducing running costs and time.
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Khmyrova, E. N., M. S. Tutanova, and D. Tokar. "Creation of control network for aerial surveys in open-pit workings using UAV." Interexpo GEO-Siberia 1 (May 18, 2022): 69–75. http://dx.doi.org/10.33764/2618-981x-2022-1-69-75.
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To assess the condition of the instrument array at the Aksu field, the earth's surface has been monitored since 2018. The territory of the mining and technical facilities of the Aksu deposit is characterized by a varying degree of complexity of the relief and a variety of the structure of the composing rocks. At the first stage, instrumental geodetic monitoring was organized to identify active deformations on the object under study using observation profile lines located in the zone of Earth surface movements. Based on the monitoring results, an assessment of the condition of the instrument array of the deposit was carried out and decisions were made on systematic observations of the movement of the Earth's surface using digital aerial photography. A deformation monitoring program has been developed at the site under study, including a project for creating a geometric pattern of signs and a zone of possible and existing deformations has been determined. Aerial photography was carried out with the help of UAVs at intervals every half a year starting in 2020. According to the results of aerial survey, local zones of new deformations on the earth's surface were obtained, as a result of mining underground work at the Aksu mine. Monitoring continues, the next flight of aerial photography is planned for May-June 2022.
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MAGOUN, AUDREY J., JUSTINA C. RAY, DEVIN S. JOHNSON, PATRICK VALKENBURG, F. NEIL DAWSON, and JEFF BOWMAN. "Modeling Wolverine Occurrence Using Aerial Surveys of Tracks in Snow." Journal of Wildlife Management 71, no. 7 (2007): 2221. http://dx.doi.org/10.2193/2006-372.
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Kemper, G., A. Weidauer, and T. Coppack. "MONITORING SEABIRDS AND MARINE MAMMALS BY GEOREFERENCED AERIAL PHOTOGRAPHY." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B8 (June 23, 2016): 689–94. http://dx.doi.org/10.5194/isprs-archives-xli-b8-689-2016.
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The assessment of anthropogenic impacts on the marine environment is challenged by the accessibility, accuracy and validity of biogeographical information. Offshore wind farm projects require large-scale ecological surveys before, during and after construction, in order to assess potential effects on the distribution and abundance of protected species. The robustness of site-specific population estimates depends largely on the extent and design of spatial coverage and the accuracy of the applied census technique. Standard environmental assessment studies in Germany have so far included aerial visual surveys to evaluate potential impacts of offshore wind farms on seabirds and marine mammals. However, low flight altitudes, necessary for the visual classification of species, disturb sensitive bird species and also hold significant safety risks for the observers. Thus, aerial surveys based on high-resolution digital imagery, which can be carried out at higher (safer) flight altitudes (beyond the rotor-swept zone of the wind turbines) have become a mandatory requirement, technically solving the problem of distant-related observation bias. A purpose-assembled imagery system including medium-format cameras in conjunction with a dedicated geo-positioning platform delivers series of orthogonal digital images that meet the current technical requirements of authorities for surveying marine wildlife at a comparatively low cost. At a flight altitude of 425 m, a focal length of 110 mm, implemented forward motion compensation (FMC) and exposure times ranging between 1/1600 and 1/1000 s, the twin-camera system generates high quality 16 bit RGB images with a ground sampling distance (GSD) of 2 cm and an image footprint of 155 x 410 m. The image files are readily transferrable to a GIS environment for further editing, taking overlapping image areas and areas affected by glare into account. The imagery can be routinely screened by the human eye guided by purpose-programmed software to distinguish biological from non-biological signals. Each detected seabird or marine mammal signal is identified to species level or assigned to a species group and automatically saved into a geo-database for subsequent quality assurance, geo-statistical analyses and data export to third-party users. The relative size of a detected object can be accurately measured which provides key information for species-identification. During the development and testing of this system until 2015, more than 40 surveys have produced around 500.000 digital aerial images, of which some were taken in specially protected areas (SPA) of the Baltic Sea and thus include a wide range of relevant species. Here, we present the technical principles of this comparatively new survey approach and discuss the key methodological challenges related to optimizing survey design and workflow in view of the pending regulatory requirements for effective environmental impact assessments.
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Kemper, G., A. Weidauer, and T. Coppack. "MONITORING SEABIRDS AND MARINE MAMMALS BY GEOREFERENCED AERIAL PHOTOGRAPHY." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B8 (June 23, 2016): 689–94. http://dx.doi.org/10.5194/isprsarchives-xli-b8-689-2016.
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The assessment of anthropogenic impacts on the marine environment is challenged by the accessibility, accuracy and validity of biogeographical information. Offshore wind farm projects require large-scale ecological surveys before, during and after construction, in order to assess potential effects on the distribution and abundance of protected species. The robustness of site-specific population estimates depends largely on the extent and design of spatial coverage and the accuracy of the applied census technique. Standard environmental assessment studies in Germany have so far included aerial visual surveys to evaluate potential impacts of offshore wind farms on seabirds and marine mammals. However, low flight altitudes, necessary for the visual classification of species, disturb sensitive bird species and also hold significant safety risks for the observers. Thus, aerial surveys based on high-resolution digital imagery, which can be carried out at higher (safer) flight altitudes (beyond the rotor-swept zone of the wind turbines) have become a mandatory requirement, technically solving the problem of distant-related observation bias. A purpose-assembled imagery system including medium-format cameras in conjunction with a dedicated geo-positioning platform delivers series of orthogonal digital images that meet the current technical requirements of authorities for surveying marine wildlife at a comparatively low cost. At a flight altitude of 425 m, a focal length of 110 mm, implemented forward motion compensation (FMC) and exposure times ranging between 1/1600 and 1/1000 s, the twin-camera system generates high quality 16 bit RGB images with a ground sampling distance (GSD) of 2 cm and an image footprint of 155 x 410 m. The image files are readily transferrable to a GIS environment for further editing, taking overlapping image areas and areas affected by glare into account. The imagery can be routinely screened by the human eye guided by purpose-programmed software to distinguish biological from non-biological signals. Each detected seabird or marine mammal signal is identified to species level or assigned to a species group and automatically saved into a geo-database for subsequent quality assurance, geo-statistical analyses and data export to third-party users. The relative size of a detected object can be accurately measured which provides key information for species-identification. During the development and testing of this system until 2015, more than 40 surveys have produced around 500.000 digital aerial images, of which some were taken in specially protected areas (SPA) of the Baltic Sea and thus include a wide range of relevant species. Here, we present the technical principles of this comparatively new survey approach and discuss the key methodological challenges related to optimizing survey design and workflow in view of the pending regulatory requirements for effective environmental impact assessments.
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Thompson, Scott, Graham Thompson, Jessica Sackmann, Julia Spark, and Tristan Brown. "Using high-definition aerial photography to search in 3D for malleefowl mounds is a cost-effective alternative to ground searches." Pacific Conservation Biology 21, no. 3 (2015): 208. http://dx.doi.org/10.1071/pc14919.
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The threatened malleefowl (Leipoa ocellata) constructs a large (often >3 m) incubator mound (nest) that is considered a useful proxy for surveying its presence and abundance in the context of an environmental impact assessment. Here we report on the effectiveness and relative cost of using high-definition aerial photography to search in 3D for malleefowl mounds by comparing results to those of earlier ground-based searches. High-definition colour aerial photography was taken of an area of ~7014 ha and searched in 3D for malleefowl mounds. All 24 active (i.e. in use) malleefowl mounds known before the examination of aerial photography were detected using the new assessment technique. Of the 108 total mounds (active and inactive) known from earlier on-ground surveys, 94 (87%) were recorded using the new technique. Mounds not detected were all old and weathered, many barely above ground level and some with vegetation growing in the crater. Approximately 6.3% of the identifications considered ‘confident’ and ~35.0% considered ‘potential’ based on the aerial photography proved to be false positives. The cost of detecting malleefowl mounds using the interpretation of high-definition 3D colour aerial photography and then subsequently examining these areas on the ground is appreciably cheaper than on-ground grid searches.
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Yamamoto, Hajime. "Aerial Surveys and Geographic Information in Modern China." Abstracts of the ICA 1 (July 15, 2019): 1–2. http://dx.doi.org/10.5194/ica-abs-1-414-2019.
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<p><strong>Abstract.</strong> Today when online satellite images are just a click away, access to geographic information showing the latest images of the globe has dramatically expanded, and historico-geographic research based on such information is flourishing. However, in the study of Chinese history, historical research employing GIS or similar technologies is still in its infancy, since “historical” geographic information with a high degree of precision are lacking. From within the ambit of Chinese geographic information, this report specifically highlights aerial surveys effected during the Republic of China era. To start, we review the history of domestic aerial surveys during R. O. C. period. Then, focusing on Nanjing as an example, we proceed to introduce maps that were actually created based on aerial surveys.</p><p>Chinese aerial surveys date back to around 1930. At the Nationalist Party’s General Assembly in 1929, partisans proposed for the need for aerial surveys. In 1930, the “Aerial Photography and Survey Research Team” was formed within the General Land Survey Department at General Staff Headquarters (National Army of the Republic of China). Consequently, foreign technicians were invited to provide relevant education/training. In June 1931, China’s pioneer initiative in aerial photography took place in Zhejiang province. The aim of aerial surveys in those early days was to create maps for military purposes. Between 1932 and 1939, topographic maps of fortifications located in areas such as the Jiangnan district were prepared. Further, starting from around the same period until the Sino-Japanese War, land registry maps based on aerial surveys were also produced. After the Sino-Japanese War ended, the above-mentioned directorate handed over responsibility for aerial surveys to the Naval General Staff. However, in 1949 the Chinese Communist Party confiscated the maps theretofore produced.</p><p>Although the aerial photographs and the geographic information produced therefrom during the R. O. C. era were seized by the People’s Republic of China, in actuality, some had previously been transferred to Taiwan. The topographic maps of the Nanjing metropolitan area (一萬分一南京城廂附近圖), based on aerial surveys and drawn in 1932, are currently archived at Academia Historica in Taipei. Comprising a total of 16 sheets, these maps were drawn on a scale of 1:10,000 by the General Land Survey Department.</p><p>Similarly, other maps (各省分幅地形圖) produced by the General Land Survey Department, comprising a total of 56 sheets and partly detailing Nanjing, are now in the possession of Academia Sinica in Taipei. There was no information about photographing or making in these maps. But almost the same maps were archived at Library of Congress in Washington D. C. According to those maps at LC, based on aerial photographs taken and surveys conducted in 1933, these topographic maps (1:10,000 scale) were completed in 1936.</p><p>The examples introduced above are topographic maps based on aerial photography. However, starting in 1937, land registry maps were also created. Detailing the outskirts of Nanjing (1:1,000 scale) and comprising a total of 121 sheets, they are now archived at Academia Historica. While the land registry maps were produced in 1937, supplementary surveys were effected following the Sino-Japanese War in 1947.</p><p>Since the geographic information based on aerial surveys during the R. O. C. era in China were precise, they can serve as a source of manifold information. This report only delved into information developed by the Government of the R. O. C., but it is becoming evident that U. S. Armed Forces and Japan also produced geographic information of their own based on aerial surveys. If the comprehensive panorama captured by all three protagonists can be illuminated, further advances in Chinese historico-geographic studies employing geographic information will be forthcoming.</p>
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Ievsiukov, Taras, Borys Chetverikov, Іvan Kovalchuk, Іvan Openko, Оleksandr Shevchenko, Yanina Stepchuk, and Оleksandr Makarov. "GEODESY, CARTOGRAPHY AND AERIAL PHOTOGRAPHY." GEODESY, CARTOGRAPHY AND AERIAL PHOTOGRAPHY 94,2021, no. 94 (2021): 44–53. http://dx.doi.org/10.23939/istcgcap2021.94.044.
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Elaboration of the method of creating a web-GIS of Polish burials at the Baikove Cemetery in Kyiv. Achieving this goal involves the following tasks: to develop the structure of the geographic information system, its framework and to fill the file database. For realization of the set tasks the technological scheme consisting of 12 stages of work is offered. The first stage involved the collection of cartographic and descriptive data on the territory of the object of study, as well as the search for possible registers of Polish burials within the object under study. In the second stage, field surveys were performed to determine the coordinates of each grave of the Polish burials at the Baikove Cemetery using a GIS tablet with an RTK antenna LT700H (accuracy up to 0.30 m). The total number of coordinated points was 565, which were concentrated in 7 sections of the cemetery. The third stage included the coordination of reference points and the binding of this support in the GIS MapInfo environment of the fragment of the topographic plan of Kyiv on a scale of 1: 2000 to the territory of the Baikove Cemetery. There were a total of 11 landmarks. The maximum binding error is 0.2 m. In the fourth stage, all point objects were displayed according to their coordinates on the basis of the map and the corresponding symbols were selected. The next step was to develop and populate a relational database for point objects. The database contained the following columns: grave number, name and surname of the buried person, grave coordinates and hyperlinks to burial information in the file database. Next, all map layers were exported to html format, and the point object layer was exported to kml format using a universal translator, which allowed to view burial data in GoogleEarth. At the eighth stage of the technological scheme the structure of layouts of each html-page of the created online GIS was developed. All map data had hyperlinks to the selected AOI objects. In the case of the Baikove Cemetery scheme, plots with Polish burials were marked. Clicking on them opened a topographic plan with marked point objects of burials. In turn, when you click on them, information about the burial appeared from the file database. At the tenth stage, 5 sheets of topographic plans with burials were generated. One sheet of scale 1: 2000 and four sheets of scale 1: 500, for better "spreading" and initialization of burials. The eleventh stage is devoted to the creation and filling of a file database on Polish burials. This database contained the following structure: photo of the burial, coordinates, surname and name, years of life, additional photographs (if available), sex of the buried person, interpreted inscription on the tombstone, as well as, if possible, detailed information and belonging of the buried person to a certain profession, its outstanding achievements and accomplishments. At the last stage, the hyperlinks of the transition between the pages were configured and the system was tested. The scientific novelty lies in the development of the concept of joint use of various applications of geoinformation and non-geoinformation purposes. The technological scheme of creation of WEB-GIS of Polish burials of the Baikove Cemetery in Kyiv is offered. Implemented geographic information system is designed for inventory of burials, analysis of the condition of tombstones and their spatial location in the cemetery. In addition, the created GIS can be used for tourism purposes and in the study of historical figures of Polish origin.
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Challis, Keith, Ziga Kokalj, Mark Kincey, Derek Moscrop, and Andy J. Howard. "Airborne lidar and historic environment records." Antiquity 82, no. 318 (December 1, 2008): 1055–64. http://dx.doi.org/10.1017/s0003598x00097775.
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AbstractThe authors assess the potential contribution of lidar surveys to national inventories of archaeological resources (‘Historic Environment Records’), and compare the relative costs and sensitivity of lidar and aerial photography.
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Taylor, Jessica K. D., Robert D. Kenney, Donald J. LeRoi, and Scott D. Kraus. "Automated Vertical Photography for Detecting Pelagic Species in Multitaxon Aerial Surveys." Marine Technology Society Journal 48, no. 1 (January 1, 2014): 36–48. http://dx.doi.org/10.4031/mtsj.48.1.9.
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AbstractMarine aerial surveys are designed to maximize the potential for detecting target species. Collecting data on different taxa from the same platform is economically advantageous but normally comes at the cost of compromising optimal taxon-specific scanning patterns and survey parameters, in particular altitude. Here, we describe simultaneous visual and photographic sampling methods as a proof of concept for detecting large whales and turtles from a single aircraft, despite very different sighting cues. Data were collected for fishing gear, fish, sharks, turtles, seals, dolphins, and whales using two observers and automated vertical photography. The photographic method documented an area directly beneath the aircraft that would otherwise have been obscured from observers. Preliminary density estimates were calculated for five species for which there were sufficient sample sizes from both methods after an initial year of data collection. The photographic method yielded significantly higher mean density estimates for loggerhead turtles, ocean sunfish, and blue sharks (p < 0.01), despite sampling a substantially smaller area than visual scanning (less than 11%). Density estimates from these two methods were not significantly different for leatherback turtles or basking sharks (p > 0.05), two of the largest species included in the analysis, which are relatively easy to detect by both methods. Although postflight manual processing of photographic data was extensive, this sampling method comes at no additional in-flight effort and obtains high-quality digital documentation of sightings on the trackline. Future directions for this project include automating photographic sighting detections, expanding the area covered by photography, and performing morphometric measurement assessments.
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Hlotov, Volodymyr, Alla Hunina, Ihor Kolb, Vadim Kolesnichenko, and Ihor Trevoho. "THE STUDY OF THE “CETUS” UNMANNED AERIAL VEHICLE FOR TOPOGRAPHIC AERIAL SURVEYING." Geodesy and cartography 47, no. 2 (August 16, 2021): 96–103. http://dx.doi.org/10.3846/gac.2021.12120.
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The work aims to analyze and study the possibilities of using “Cetus” unmanned aerial vehicle (UAV) for performing topographic aerial surveys. The authors developed and tested aircraft-type UAV for topographic aerial photography. The studies were conducted on a specialized landfill, at which there is an appropriate number of situational points whose coordinates are determined with high accuracy. These points were used as both reference and control points. The obtained UAV aerial survey materials were subjected to a phototriangulation process to determine the orientation elements and to analyze, first and foremost, the angular orientation elements. The surveying was carried out on a mountainous territory, where the spatial coordinates of 37 situational points were determined by the method of ground-based GPS survey with an average accuracy of up to 0.05 m. These points were used as reference and control points. Aerial photography was performed in such a way that the scale of the images was as uniform as possible. The design solutions implemented in the Cetus UAV provide all the possibilities to perform aerial surveys of territories in strict compliance with the projected flight parameters. UAV equipment provides the necessary real-time correction of the position of the aerial camera. At the same time the optimum straightness of routes, stability of scales and mutual overlapping of pictures is reached. Regarding the accuracy of obtaining the spatial coordinates of the points of terrain objects, using “Cetus” UAV surveys, plans can even be made on a scale of even 1: 1000. As a result of the creation of the UAV “Cetus”, it became possible to perform the topographic aerial survey of the territories and to create large-scale orthophotos that fully meet the instructions. As a result of testing the “Cetus” UAV, it can be used in production processes when drawing up topographic plans for a large-scale series: 1: 1000 – 1: 5000, which will significantly save the cost of performing topographic work.
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Colville, David, Brittany Reeves, Darien Ure, Bill Livingstone, and Heather Stewart. "Mapping the topography and land cover of Sable Island." Proceedings of the Nova Scotian Institute of Science (NSIS) 48, no. 2 (May 7, 2016): 285. http://dx.doi.org/10.15273/pnsis.v48i2.6660.
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In September 2014 the Applied Geomatics Research Group (AGRG) completed a third aerial mapping campaign of Sable Island. The AGRG first mapped the island in October 2002 with an aerial photography survey. Then in August 2009 AGRG conducted an aerial photography and Light Detection And Ranging (LiDAR) survey. Five years later these same technologies were deployed again. Each of these surveys led to an orthophoto mosaic of the island and a mapping of the land cover. The 2009 and 2014 surveys also mapped the island’s topography using Digital Surface Models (DSMs) derived from the LiDAR data. Ground-truthing efforts associated with each survey provided data to assist with the interpretation and validation of the results.The repeat surveys resulted in an excellent opportunity to quantify the topographic and land cover changes that have occurred on the island. The mapped results provide a comparison of how and where these changes have occurred over the years. AGRG is working with Parks Canada to better understand how the topography and land cover are changing. This understanding will contribute to Parks Canada Ecological Integrity monitoring program for Sable Island and inform the management planning process for one of Canada’s newest national parks.
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König, Max, and Matthew Sturm. "Mapping snow distribution in the Alaskan Arctic using aerial photography and topographic relationships." Water Resources Research 34, no. 12 (December 1998): 3471–83. http://dx.doi.org/10.1029/98wr02514.
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Jones, Trevor, Rasa Baceviciene, Tyler Vukmer, Chante Karimkhani, Lindsay Boyers, Robert Dellavalle, and Ryan Gamble. "Impact of Ultraviolet Photography on Sun Safety Practices of Snow Sport Industry Conference Attendees." Open Dermatology Journal 8, no. 1 (February 21, 2014): 8–11. http://dx.doi.org/10.2174/1874372201408010008.
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Studies have established ultraviolet (UV) exposure with increased melanoma skin cancer risk. The combination of UV exposure, high altitude, and reflection of UV rays on the snow may create a particularly relevant and high-risk population amongst those who participate in snow sports. The current study aims to determine the effectiveness of a UV-photography and personalized counseling-based intervention to improve sun protection awareness on the snow sport enthusiast population. Participants were recruited at the 2013 SnowSports Industries American (SIA) Snow Show in Denver to complete a 14 question pre-survey assessing sun-safety awareness followed by a Faraghan Medical Elise Digital UV Camera photograph of their face and counseling regarding individual results. Participants were contacted one to two months later by telephone to complete a ten question post-survey. Forty-one percent of participants (46/112) completed both pre- and post-surveys. The UV photography based intervention influenced the opinions and behaviors of sun protection in 78% of male and 62% of female participants with sunscreen use identified as the most frequently modified behavior (53%). While valid barriers to UV photography use include a current lack of reimbursement and lack of public knowledge of its utility, our study indicates the potential impact of UV photography-based interventions among high-risk populations who avidly participate in snow sports.
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Sutugina, Irina. "INFORMATION SUPPORT FOR THE CONSTRUCTION ON RURAL AREAS BASED ON AERIAL PHOTOGRAPHY." Construction and Architecture 10, no. 2 (June 27, 2022): 86–90. http://dx.doi.org/10.29039/2308-0191-2022-10-2-86-90.
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The agro-industrial complex is one of the most promising and dynamically developing industries, which implies the creation of a single complex for the goal of optimizing cooperation and work of different agricultural directions.
Information support of rural construction requires implementation of materials related to engineering and geodetic surveys.
The article presents the results of the analysis of the possibilities of applying aerial survey data for the creation of cartographic materials, which can later be used for solving of various problems, including information support for surveys for construction on rural areas. The requirements for the precision of materials depending on the categories of land and scale of cartographic materials are considered.
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Đorđević, Dejan Radovan, Uroš Đurić, Saša Tomislav Bakrač, Siniša Milanko Drobnjak, and Stevan Radojčić. "Using Historical Aerial Photography in Landslide Monitoring: Umka Case Study, Serbia." Land 11, no. 12 (December 13, 2022): 2282. http://dx.doi.org/10.3390/land11122282.
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The application of remote sensing methods provides useful information that can be used for numerous research. Thus, spatial changes in soil, vegetation, hydrography and such can be analyzed. By analyzing the data obtained by remote sensing methods, high-quality and important data can be obtained for monitoring changes in soil movement caused by landslides. This method provides the possibility of determining the state of the observed space over a longer period of time. Historical aerial imagery has a high level of spatial detail analysis. Comparative analysis of the aerial imagery from the past, recent ones and other surveys can certainly provide information on the trend of ground movement, as well as lead to conclusions for taking specific measures. The present paper gives an example of the analysis of the particular area of the “Umka” landslide based on historical surveys. The “Umka” landslide is located along the right bank of the Sava River near the city of Belgrade, which, with its long-term activity, jeopardizes residential buildings, infrastructure facilities and the population that still lives on it.
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Witting, Lars, and Daniel G. Pike. "Distance estimation experiment for aerial minke whale surveys." NAMMCO Scientific Publications 7 (September 1, 2009): 111. http://dx.doi.org/10.7557/3.2709.
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A comparative study between aerial cue–counting and digital photography surveys for minke whales conducted in Faxaflói Bay in September 2003 is used to check the perpendicular distances estimated by the cue-counting observers. The study involved 2 aircraft with the photo plane at 1,700 feet flying above the cue–counting plane at 750 feet. The observer–based distance estimates were calculated from head angles estimated by angle-boards and declination angles estimated by declinometers. These distances were checked against image–based estimates of the perpendicular distance to the same whale. The 2 independent distance estimates were obtained for 21 sightings of minke whale, and there was a good agreement between the 2 types of estimates. The relative absolute deviations between the 2 estimates were on average 23% (se: 6%), with the errors in the observer–based distance estimates resembling that of a log-normal distribution. The linear regression of the observer–based estimates (obs) on the image–based estimates (img) was Obs=1.1Img (R2=0.85) with an intercept fixed at zero. There was no evidence of a distance estimation bias that could generate a positive bias in the absolute abundance estimated by cue–counting.
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Kingsley, Michael CS, and Isabelle Gauthier. "Visibility of St Lawrence belugas to aerial photography, estimated by direct observation." NAMMCO Scientific Publications 4 (July 22, 2002): 259. http://dx.doi.org/10.7557/3.2848.
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The depleted population of belugas (Delphinapterus leucas) inhabiting the St Lawrence estuary, Canada, was monitored by periodic photographic aerial surveys. In order to correct counts made on aerial survey film and to obtain an estimate of the true size of the population, the diving behaviour and the visibility from the air of these animals was studied. A Secchi-disk turbidity survey in the belugas’ summer range showed that water clarity varied between 1.5 m and 11.6 m. By studying aerial photographs of sheet-plastic models of belugas that had been sunk to different depths below the surface, we found that models of white adults could be seen down to about the same depth as a Secchi disk, but no deeper. Smaller models of dark-grey juveniles could only be seen down to about 50% of Secchi-disk depth. By observing groups of belugas from a hovering helicopter and recording their disappearances and re-appearances, it was found that they were visible for 44.3% of the time, and that an appropriate correction for single photographs would be to multiply the photographic count by about 222% (SE 20%). For surveys in which there was overlap between adjacent frames, the estimated correction would be 209% (SE 16%). This correction factor was slightly conservative and gave an estimate of the true size of the population, based on a single survey, of 1,202 belugas (SE 189) in 1997. An estimate for 1997 based on smoothing 5 surveys 1988–1997 was 1,238 (SE 119).
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Harder, Phillip, Michael Schirmer, John Pomeroy, and Warren Helgason. "Accuracy of snow depth estimation in mountain and prairie environments by an unmanned aerial vehicle." Cryosphere 10, no. 6 (November 2, 2016): 2559–71. http://dx.doi.org/10.5194/tc-10-2559-2016.
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Abstract. Quantifying the spatial distribution of snow is crucial to predict and assess its water resource potential and understand land–atmosphere interactions. High-resolution remote sensing of snow depth has been limited to terrestrial and airborne laser scanning and more recently with application of structure from motion (SfM) techniques to airborne (manned and unmanned) imagery. In this study, photography from a small unmanned aerial vehicle (UAV) was used to generate digital surface models (DSMs) and orthomosaics for snow cover at a cultivated agricultural Canadian prairie and a sparsely vegetated Rocky Mountain alpine ridgetop site using SfM. The accuracy and repeatability of this method to quantify snow depth, changes in depth and its spatial variability was assessed for different terrain types over time. Root mean square errors in snow depth estimation from differencing snow-covered and non-snow-covered DSMs were 8.8 cm for a short prairie grain stubble surface, 13.7 cm for a tall prairie grain stubble surface and 8.5 cm for an alpine mountain surface. This technique provided useful information on maximum snow accumulation and snow-covered area depletion at all sites, while temporal changes in snow depth could also be quantified at the alpine site due to the deeper snowpack and consequent higher signal-to-noise ratio. The application of SfM to UAV photographs returns meaningful information in areas with mean snow depth > 30 cm, but the direct observation of snow depth depletion of shallow snowpacks with this method is not feasible. Accuracy varied with surface characteristics, sunlight and wind speed during the flight, with the most consistent performance found for wind speeds < 10 m s−1, clear skies, high sun angles and surfaces with negligible vegetation cover.
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Dokukin, Michail D., and Ruslan Kh Kalov. "Integrated Assessment of Exogenic Processes Potential Threat to Facilities Located on the Territory of Recreation Centre "Polyana Cheget" (Elbrus Region, Caucasus)." Materials Science Forum 931 (September 2018): 1057–62. http://dx.doi.org/10.4028/www.scientific.net/msf.931.1057.
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Integrated assessment of snow avalanches, glacial mudflows, outburst floods and rock avalanches to facilities located on the territory of Recreation centre "Polyana Cheget", based on geomorphological analysis, interpretation of multi-temporal aerial and satellite images as well as route surveys has been presented in the article.
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Naruse, Renji, and Masamu Aniya. "Some Possible Causes For Recent Variations Of Patagonian Glaciers." Annals of Glaciology 14 (1990): 351. http://dx.doi.org/10.3189/s0260305500009228.
Full textAbstract:
The Patagonian glaciers located in the southern part of the Andes between 46°30′S and 51°30′S are characterized by typical temperate conditions of heavy precipitation, rapid ice flows and high melting rates. During the austral summers of 1983–84 and 1985–86, field studies were made of the ice flow, heat balance and morphology of several glaciers in Patagonia. Coupled with aerial photographic surveys, these revealed that most glaciers had retreated extensively in the recent years, a maximum being 200 m a-1 at San Rafael Glacier from 1974 to 1986. The lower part of Soler Glacier had thinned by a rate of 5.2 m a-1 from 1983 to 1985.This paper presents three possible mechanisms to explain the large variation of temperate glaciers during the last decade, based on analyses of mass balance and dynamics of Patagonian glaciers:(1) The annual melting rate was estimated at about 10–15 m a-1 in water equivalent over the ablation area (from 350 to 1350 m a.s.l.) of Soler Glacier. Monthly mean air temperature in the coldest season (June through August) was estimated at about 0°–4°C near the termini of most glaciers in Patagonia. That temperature coincides with an air temperature which is critical for solid or liquid precipitation. The difference in the surface albedo, that is, 0.7–0.8 for new snow and 0.4–0.55 for bare ice (0.1–0.2 for debris-covered ice), results in different melting rates. Hence, a slight change in air temperature should cause an enhanced change in ice thickness by a positive feedback mechanism.(2) The flow velocity was measured or estimated and was found to change daily and seasonally by factors of 3 to 5 at Soler Glacier. The large flow velocity variation was attributed to difference in the basal sliding velocity. Consequently, a change in the amount of subglacial water or the structure of the basal water system should cause a large change in the ice flow, which in turn results in a retreat or an advance of the glacier-like “mini-surge”.(3) Frequent fluctuations of calving glaciers (e.g. San Rafael and Pio XI glaciers) have been much reported; however, information on the position of the grounding lines is very scarce. The advance or retreat of the glacier front may possibly have been affected by that of the floating terminus. The rate of calving from the ice tongue or spreading of ice shelves should mainly be controlled by the melting rate of ice in the water and by the mechanical properties of ice, and these factors are not directly related to climatic change or the surge phenomenon.
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Naruse, Renji, and Masamu Aniya. "Some Possible Causes For Recent Variations Of Patagonian Glaciers." Annals of Glaciology 14 (1990): 351. http://dx.doi.org/10.1017/s0260305500009228.
Full textAbstract:
The Patagonian glaciers located in the southern part of the Andes between 46°30′S and 51°30′S are characterized by typical temperate conditions of heavy precipitation, rapid ice flows and high melting rates. During the austral summers of 1983–84 and 1985–86, field studies were made of the ice flow, heat balance and morphology of several glaciers in Patagonia. Coupled with aerial photographic surveys, these revealed that most glaciers had retreated extensively in the recent years, a maximum being 200 m a-1 at San Rafael Glacier from 1974 to 1986. The lower part of Soler Glacier had thinned by a rate of 5.2 m a-1 from 1983 to 1985. This paper presents three possible mechanisms to explain the large variation of temperate glaciers during the last decade, based on analyses of mass balance and dynamics of Patagonian glaciers: (1) The annual melting rate was estimated at about 10–15 m a-1 in water equivalent over the ablation area (from 350 to 1350 m a.s.l.) of Soler Glacier. Monthly mean air temperature in the coldest season (June through August) was estimated at about 0°–4°C near the termini of most glaciers in Patagonia. That temperature coincides with an air temperature which is critical for solid or liquid precipitation. The difference in the surface albedo, that is, 0.7–0.8 for new snow and 0.4–0.55 for bare ice (0.1–0.2 for debris-covered ice), results in different melting rates. Hence, a slight change in air temperature should cause an enhanced change in ice thickness by a positive feedback mechanism. (2) The flow velocity was measured or estimated and was found to change daily and seasonally by factors of 3 to 5 at Soler Glacier. The large flow velocity variation was attributed to difference in the basal sliding velocity. Consequently, a change in the amount of subglacial water or the structure of the basal water system should cause a large change in the ice flow, which in turn results in a retreat or an advance of the glacier-like “mini-surge”. (3) Frequent fluctuations of calving glaciers (e.g. San Rafael and Pio XI glaciers) have been much reported; however, information on the position of the grounding lines is very scarce. The advance or retreat of the glacier front may possibly have been affected by that of the floating terminus. The rate of calving from the ice tongue or spreading of ice shelves should mainly be controlled by the melting rate of ice in the water and by the mechanical properties of ice, and these factors are not directly related to climatic change or the surge phenomenon.
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De Michele, C., F. Avanzi, D. Passoni, R. Barzaghi, L. Pinto, P. Dosso, A. Ghezzi, R. Gianatti, and G. Della Vedova. "Microscale variability of snow depth using U.A.S. technology." Cryosphere Discussions 9, no. 1 (February 20, 2015): 1047–75. http://dx.doi.org/10.5194/tcd-9-1047-2015.
Full textAbstract:
Abstract. We investigate the capabilities of photogrammetry-based surveys with Unmanned Aerial Systems (U.A.S.) to retrieve the snow depth distribution at cm resolution over a small alpine area (~300 000 m2). For this purpose, we have designed two field campaigns during the 2013/2014 winter season. In the first survey, realized at the beginning of the accumulation season, the digital elevation model of bare soil has been obtained. The second survey, made at the end of the accumulation season, allowed to determine the snow depth distribution as difference with respect to the previous aerial survey. 12 manual measurements of snow depth were collected at random positions in order to run a point comparison with U.A.S. measurements. The spatial integration of U.A.S. snow depth measurements allowed to estimate the snow volume accumulated over the area. We compare this volume estimation with the ones provided by classical interpolation techniques of the 12 point measurements. Results show that the U.A.S. technique provides an accurate estimation of point snow depth values (the average difference with reference to manual measurements is of −7.3 cm), and a distributed evaluation of the snow accumulation patterns. Moreover, the interpolation techniques considered return average differences in snow volume estimation, with respect to the one obtained through the U.A.S. technology, equal to ~21%.
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Woo, Ming-ko, and Kathy L. Young. "Disappearing semi-permanent snow in the High Arctic and its consequences." Journal of Glaciology 60, no. 219 (2014): 192–200. http://dx.doi.org/10.3189/2014jog13j150.
Full textAbstract:
AbstractSemi-permanent snow is part of the continuum between seasonal snow and glacier ice. Although ubiquitous in the High Arctic, most late-lying snow banks and snow beds have lost their perennial status over the past decade as the summers have become progressively warmer. The loss over the past decade is the most unprecedented since aerial photography of the Canadian Arctic islands was first undertaken over half a century ago, and it has produced observable thermal, hydrological and ecological impacts. Where the ground has become exposed beneath the perennial snow cover, seasonal ground thaw has deepened. Tundra ponds and patchy wetlands fed principally by meltwater in the summer have suffered water-level decline or desiccation. The water balance of headwater basins is also affected, losing a buffering vehicle that accumulates storage surplus from the wet cool years to support streamflow and evaporation in the dry warm years. The tundra vegetation, already sparse, undergoes changes in the long term. As an essential source of water in the polar desert environment, the widespread distribution of semi-permanent snow magnifies its Arctic-wide importance.
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Hickson, Catherine, John Pollack, Lambertus Struik, Lee Hollis, and Chas Yonge. "Discovery of a significant cave entrance in stripe karst, Horsethief Creek Group, Wells Gray Provincial Park, British Columbia, Canada." Canadian Journal of Earth Sciences 57, no. 5 (May 2020): 662–70. http://dx.doi.org/10.1139/cjes-2019-0163.
Full textAbstract:
In April 2018, a significant cave entrance was recognized during an aerial survey in Wells Gray Provincial Park, British Columbia. A September 2018 assessment of the site confirmed one of the largest known, and previously undocumented, cave entrances in Canada. The feature is a large vertically walled sink swallowing a small river, likely leading to a spring 2.16 km horizontally from, and 460 m below, the sink. The entrance shaft was partially descended, surveyed, and found to have a volume of over 450 000 m3. Formed in a carbonate unit of the upper Proterozoic Horsethief Creek Group, the cave entrance occurs in stripe karst extending well beyond the known cave drainage. The disappearing river drains an area of 6.3 km2 in a valley containing two small glaciers. The river has a low flow (September) rate estimated at 0.3–0.5 m3/s, comparable with some of the largest sinks in Canada. Historic aerial photographs of the area show the entrance was hidden by perennial snowfields until regional climatic warming caused the snow plug to collapse sometime within the past decade.
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Drinkwater, Mark R., and Julian A. Dowdeswell. "A Multi-Sensor Approach to the Interpretation of Radar Altimeter Wave Forms from Two Arctic Ice Caps." Annals of Glaciology 9 (1987): 60–68. http://dx.doi.org/10.3189/s0260305500200773.
Full textAbstract:
Data collected over Svalbard on 28 June 1984 by a 13.81 GHz airborne radar altimeter enabled analysis of signals returned from two relatively large ice masses. Wave forms received over the ice caps of Austfonna and Vestfonna are analysed with the aid of existing aerial photography, radio echo-sounding data, and Landsat MSS images acquired close to the date of the altimeter flight. Results indicate that altimeter wave forms are controlled mainly by surface roughness and scattering characteristics. Wet snow surfaces have narrow 3 dB back-scatter half-angles and cause high-amplitude signals, in contrast to relatively dry snow surfaces with lower-amplitude diffuse signals. Metre-scale surface roughness primarily affects wave-form amplitude and leading-edge slope, this becoming apparent over ice streams on Vestfonna.
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Drinkwater, Mark R., and Julian A. Dowdeswell. "A Multi-Sensor Approach to the Interpretation of Radar Altimeter Wave Forms from Two Arctic Ice Caps." Annals of Glaciology 9 (1987): 60–68. http://dx.doi.org/10.1017/s0260305500000392.
Full textAbstract:
Data collected over Svalbard on 28 June 1984 by a 13.81 GHz airborne radar altimeter enabled analysis of signals returned from two relatively large ice masses. Wave forms received over the ice caps of Austfonna and Vestfonna are analysed with the aid of existing aerial photography, radio echo-sounding data, and Landsat MSS images acquired close to the date of the altimeter flight. Results indicate that altimeter wave forms are controlled mainly by surface roughness and scattering characteristics. Wet snow surfaces have narrow 3 dB back-scatter half-angles and cause high-amplitude signals, in contrast to relatively dry snow surfaces with lower-amplitude diffuse signals. Metre-scale surface roughness primarily affects wave-form amplitude and leading-edge slope, this becoming apparent over ice streams on Vestfonna.
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Drinkwater, Mark R., and Julian A. Dowdeswell. "A Multi-Sensor Approach to the Interpretation of Radar Altimeter Wave Forms from Two Arctic Ice Caps." Annals of Glaciology 9 (1987): 60–68. http://dx.doi.org/10.1017/s0260305500200773.
Full textAbstract:
Data collected over Svalbard on 28 June 1984 by a 13.81 GHz airborne radar altimeter enabled analysis of signals returned from two relatively large ice masses. Wave forms received over the ice caps of Austfonna and Vestfonna are analysed with the aid of existing aerial photography, radio echo-sounding data, and Landsat MSS images acquired close to the date of the altimeter flight. Results indicate that altimeter wave forms are controlled mainly by surface roughness and scattering characteristics. Wet snow surfaces have narrow 3 dB back-scatter half-angles and cause high-amplitude signals, in contrast to relatively dry snow surfaces with lower-amplitude diffuse signals. Metre-scale surface roughness primarily affects wave-form amplitude and leading-edge slope, this becoming apparent over ice streams on Vestfonna.
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Mazhitova, Gulnur, Dina Shugulova, and Igor Sedelnikov. "About the experience of developing a GIS project of the university campus." InterCarto. InterGIS 28, no. 1 (2022): 603–12. http://dx.doi.org/10.35595/2414-9179-2022-1-28-603-612.
Full textAbstract:
The article discusses the results of the work on the design and creation of a GIS project of the university campus. A model and methodology for creating a geographical information system (GIS) of the university campus was developed and tested in the Non-profit limited company “Manash Kozybayev North Kazakhstan university” setting. The GIS was created on the basis of open spatial data of the Remote Sensing of the Earth, materials of ground photography and aerial photography from an unmanned aerial vehicle (UAV). Geoinformation mapping and modeling was carried out using specialized programs: ArcGIS 10.4 (ESRI Inc.), Agisoft PhotoScan Professional Edition. The article presents the GIS structure of the campus, its main elements, and describes the stages of development. The work on the creation of GIS included the following stages: the development of its preliminary model and structure, the collection of the necessary initial information and data about the studied territory, the conduct of ground surveys and aerial photography, field work, processing of collected materials in special software applications, the creation of an electronic map and database, filling and correcting the latter. The campus GIS includes a digital cartographic framework and an associated database. Its structure contains a number of modules that combine thematic layers. Along with this, geo-referenced photorealistic three-dimensional models of university buildings were created during the research. A 3D model of the campus was built on the basis of aerial photography materials from the UAV. Developed GIS, its functionality can be useful to the university and find application in solving practical problems. The research was carried out within the framework of grant funding under the Sustainability Living Lab program.
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Magnússon, E., J. Muñoz-Cobo Belart, F. Pálsson, H. Ágústsson, and P. Crochet. "Geodetic mass balance record with rigorous uncertainty estimates deduced from aerial photographs and lidar data – Case study from Drangajökull ice cap, NW Iceland." Cryosphere 10, no. 1 (January 19, 2016): 159–77. http://dx.doi.org/10.5194/tc-10-159-2016.
Full textAbstract:
Abstract. In this paper we describe how recent high-resolution digital elevation models (DEMs) can be used to extract glacier surface DEMs from old aerial photographs and to evaluate the uncertainty of the mass balance record derived from the DEMs. We present a case study for Drangajökull ice cap, NW Iceland. This ice cap covered an area of 144 km2 when it was surveyed with airborne lidar in 2011. Aerial photographs spanning all or most of the ice cap are available from survey flights in 1946, 1960, 1975, 1985, 1994 and 2005. All ground control points used to constrain the orientation of the aerial photographs were obtained from the high-resolution lidar DEM. The lidar DEM was also used to estimate errors of the extracted photogrammetric DEMs in ice- and snow-free areas, at nunataks and outside the glacier margin. The derived errors of each DEM were used to constrain a spherical semivariogram model, which along with the derived errors in ice- and snow-free areas were used as inputs into 1000 sequential Gaussian simulations (SGSims). The simulations were used to estimate the possible bias in the entire glaciated part of the DEM and the 95 % confidence level of this bias. This results in bias correction varying in magnitude between 0.03 m (in 1975) and 1.66 m (in 1946) and uncertainty values between ±0.21 m (in 2005) and ±1.58 m (in 1946). Error estimation methods based on more simple proxies would typically yield 2–4 times larger error estimates. The aerial photographs used were acquired between late June and early October. An additional seasonal bias correction was therefore estimated using a degree-day model to obtain the volume change between the start of 2 glaciological years (1 October). This correction was largest for the 1960 DEM, corresponding to an average elevation change of −3.5 m or approx. three-quarters of the volume change between the 1960 and the 1975 DEMs. The total uncertainty of the derived mass balance record is dominated by uncertainty in the volume changes caused by uncertainties of the SGSim bias correction, the seasonal bias correction and the interpolation of glacier surface where data are lacking. The record shows a glacier-wide mass balance rate of Ḃ = −0.26 ± 0.04 m w.e. a−1 for the entire study period (1946–2011). We observe significant decadal variability including periods of mass gain, peaking in 1985–1994 with Ḃ = 0.27 ± 0.11 m w.e. a−1. There is a striking difference when Ḃ is calculated separately for the western and eastern halves of Drangajökull, with a reduction of eastern part on average ∼ 3 times faster than the western part. Our study emphasizes the need for applying rigorous geostatistical methods for obtaining uncertainty estimates of geodetic mass balance, the importance of seasonal corrections of DEMs from glaciers with high mass turnover and the risk of extrapolating mass balance record from one glacier to another even over short distances.
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Magnússon, E., J. M. C. Belart, F. Pálsson, H. Ágústsson, and P. Crochet. "Geodetic mass balance record with rigorous uncertainty estimates deduced from aerial photographs and LiDAR data – case study from Drangajökull ice cap, NW-Iceland." Cryosphere Discussions 9, no. 5 (September 9, 2015): 4733–85. http://dx.doi.org/10.5194/tcd-9-4733-2015.
Full textAbstract:
Abstract. In this paper we describe how recent high resolution Digital Elevation Models (DEMs) can be used as constraints for extracting glacier surface DEMs from old aerial photographs and to evaluate the uncertainty of the mass balance record derived from the DEMs. We present a case study for Drangajökull ice cap, NW-Iceland. This ice cap covered an area of 144 km2 when it was surveyed with airborne LiDAR in 2011. Aerial photographs spanning all or most of the ice cap are available from survey flights in 1946, 1960, 1975, 1985, 1994 and 2005. All ground control points used to constrain the orientation of the aerial photographs were obtained from the high resolution LiDAR DEM (2 m × 2 m cell size and vertical accuracy < 0.5 m). The LiDAR DEM was also used to estimate errors of the extracted photogrammetric DEMs in ice and snow free areas, at nunataks and outside the glacier margin. The derived errors of each DEM were used to constrain a spherical variogram model, which along with the derived errors in ice and snow free areas were used as inputs into 1000 Sequential Gaussian Simulations (SGSim). The simulations were used to estimate the possible bias in the entire glaciated part of the DEM. The derived bias correction, varying in magnitude between DEMs from 0.03 to 1.66 m (1946 DEM) was then applied. The simulation results were also used to calculate the 95 % confidence level of this bias, resulting in values between ±0.21 m (in 2005) and ±1.58 m (in 1946). Error estimation methods based on more simple proxies would typically yield 2–4 times larger error estimates. The aerial photographs used were acquired between late June and early October. An additional bias correction was therefore estimated using a degree day model to obtain the volume change between the start of two hydrological years (1 October). This correction corresponds to an average elevation change of ~ −3 m in the worst case for 1960, or about ~ 2/3 of volume change between the 1960 and the 1975 DEMs. The total uncertainty of the derived mass balance record is mostly due to uncertainty of the SGSim bias correction, the uncertainty of the seasonal bias correction and the uncertainty of the interpolated glacier surface where data is lacking. The record shows a glacier-wide mass balance rate of Ḃ = −0.250 ± 0.040 m w.e. a−1 for the entire study period (1946–2011). We observe significant decadal variability including positive periods, peaking in 1985–1994 with Ḃ = 0.26 ± 0.11 m w.e. a−1. There is a striking difference if Ḃ is calculated separately for the western and eastern halves of Drangajökull, with a reduction of eastern part on average ~ 3 times faster than the western part. Our study emphasises the need of applying rigorous geostatistical methods for obtaining uncertainty estimates of geodetic mass balance, the importance of seasonal corrections of DEMs from glaciers with high mass turnover and the risk of extrapolating mass balance record from one glacier to another even over short distances.
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Ostrowski, Piotr, Tomasz Falkowski, Dariusz Karczmarz, Przemysław Mądrzycki, and Henryk Szkudlarz. "The usefulness of low-altitude aerial photography for the assessment of channel morphodynamics of a lowland river." Annals of Warsaw University of Life Sciences – SGGW. Land Reclamation 49, no. 2 (June 1, 2017): 95–106. http://dx.doi.org/10.1515/sggw-2017-0008.
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Abstract The paper presents examples of using low-altitude aerial images of a modern river channel, acquired from an ultralight aircraft. The images have been taken for two sections of the Vistula river: in the Małopolska Gorge and near Dęblin and Gołąb. Alongside with research flights, there were also terrestrial investigations, such as echo sounding of the riverbed and geological mapping, carried out in the river channel zone. A comparison of the results of aerial and terrestrial research revealed high clarity of the images, allowing for precise identification of the evidence that indicates the specific course of river channel processes. Aerial images taken from ultralight aircrafts can significantly increase the accuracy of geological surveys of river channel zones in the Polish Lowlands due to low logistic requirements.
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Anikeeva, I. A., N. M. Babashkin, S. A. Kadnichanskiy, and S. S. Nekhin. "The Possibility and Effectiveness of Using Drones When Performing Cadastral Works." Geodesy and Cartography 938, no. 8 (September 20, 2018): 44–52. http://dx.doi.org/10.22389/0016-7126-2018-938-8-44-52.
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The analysis of the capabilities and effectiveness of the aerial survey using a drone for determining the coordinate points of the real estate objects’ boundaries with photogrammetric method in doing cadastral works basing on established requirements is given. The matters of coordinates’ definition accuracy are considered basing on the results of research trials of hardware and software systems of digital aerial photography and photogrammetric processing based on using drones and the aerial photos of the polygon. The results of a comparative analysis of the aerial survey effectiveness using drones of various types and traditional aerial survey with manned aircraft are given. The factors affecting the efficiency are analyzed. Issues of creating the legislation base for aerial survey with drones are discussed. The conclusion is made about possibility of aerial survey using unmanned aircraft to determine the coordinates of the real estate objects’ boundaries with precision meeting the established requirements. Planning aerial surveys with drones for cadastral tasks should be primarily based on economic factors (time and cost), taking into account the specific conditions of the subject and used hardware and software.
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Kurkov, V. M., T. N. Skripitsina, and A. Yu Sozonova. "METHODS AND TECHNOLOGIES FOR AERIAL SURVEYING AND GROUND PHOTOGRAMMETRIC SURVEYS FOR ARCHAEOLOGICAL PURPOSES." ECOLOGY ECONOMY INFORMATICS. GEOINFORMATION TECHNOLOGIES AND SPACE MONITORING 2, no. 5 (2020): 75–82. http://dx.doi.org/10.23885/2500-123x-2020-2-5-75-82.
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This article we consider methods and technologies of unmanned aerial surveying and close-range photogrammetric survey as applied for archeological research. We summed up the practical experience of the specialists of the Moscow State University of Geodesy and Cartography (MIIGAiK), obtained with the participation in the Bosporus archaeological expedition of the State Historical Museum on the Taman Peninsula in 2018–20. During the 3 expeditions, 18 archaeological sites were surveyed by aerial methods using UAV Geoscan 101 Geodesy and UAS DJI Phantom 4 Pro. In addition to aerial surveying, the Canon 30D digital camera with 50 mm and 14 mm focal lengths was used for groundbased, close-range photogrammetric surveys of archaeological sites. Some sites were surveyed many times during different periods of archaeological research. At all surveyed archaeological sites using photogrammetric processing methods at the Agisoft Metashape software we received survey documents (orthophoto, digital terrain models, 3D models). For some artifacts, three-dimensional metric models have been obtained using digital photogrammetry methods. Various methods of aerial surveying were used to study archaeological sites. The article gives recommendations on optimization of photography process in order to obtain reliable and informative documents for archaeological excavations. Comparison and analysis of aerial and close-range survey data was performed by the QGIS geographic information system. The information obtained using geo-information technologies will improve the quality and reliability of forecasts and hypotheses in archaeological studies.
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Takechi, Hitoshi, Shunsuke Aragaki, and Mitsuteru Irie. "Differentiation of River Sediments Fractions in UAV Aerial Images by Convolution Neural Network." Remote Sensing 13, no. 16 (August 12, 2021): 3188. http://dx.doi.org/10.3390/rs13163188.
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Riverbed material has multiple functions in river ecosystems, such as habitats, feeding grounds, spawning grounds, and shelters for aquatic organisms, and particle size of riverbed material reflects the tractive force of the channel flow. Therefore, regular surveys of riverbed material are conducted for environmental protection and river flood control projects. The field method is the most conventional riverbed material survey. However, conventional surveys of particle size of riverbed material require much labor, time, and cost to collect material on site. Furthermore, its spatial representativeness is also a problem because of the limited survey area against a wide riverbank. As a further solution to these problems, in this study, we tried an automatic classification of riverbed conditions using aerial photography with an unmanned aerial vehicle (UAV) and image recognition with artificial intelligence (AI) to improve survey efficiency. Due to using AI for image processing, a large number of images can be handled regardless of whether they are of fine or coarse particles. We tried a classification of aerial riverbed images that have the difference of particle size characteristics with a convolutional neural network (CNN). GoogLeNet, Alexnet, VGG-16 and ResNet, the common pre-trained networks, were retrained to perform the new task with the 70 riverbed images using transfer learning. Among the networks tested, GoogleNet showed the best performance for this study. The overall accuracy of the image classification reached 95.4%. On the other hand, it was supposed that shadows of the gravels caused the error of the classification. The network retrained with the images taken in the uniform temporal period gives higher accuracy for classifying the images taken in the same period as the training data. The results suggest the potential of evaluating riverbed materials using aerial photography with UAV and image recognition with CNN.