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Umarhadi, Deha Agus, and Projo Danoedoro. "Comparing canopy density measurement from UAV and hemispherical photography: an evaluation for medium resolution of remote sensing-based mapping." International Journal of Electrical and Computer Engineering (IJECE) 11, no. 1 (February 1, 2021): 356. http://dx.doi.org/10.11591/ijece.v11i1.pp356-364.
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UAV and hemispherical photography are common methods used in canopy density measurement. These two methods have opposite viewing angles where hemispherical photography measures canopy density upwardly, while UAV captures images downwardly. This study aims to analyze and compare both methods to be used as the input data for canopy density estimation when linked with a lower spatial resolution of remote sensing data i.e. Landsat image. We correlated the field data of canopy density with vegetation indices (NDVI, MSAVI, and AFRI) from Landsat-8. The canopy density values measured from UAV and hemispherical photography displayed a strong relationship with 0.706 coefficient of correlation. Further results showed that both measurements can be used in canopy density estimation using satellite imagery based on their high correlations with Landsat-based vegetation indices. The highest correlation from downward and upward measurement appeared when linked with NDVI with a correlation of 0.962 and 0.652, respectively. Downward measurement using UAV exhibited a higher relationship compared to hemispherical photography. The strong correlation between UAV data and Landsat data is because both are captured from the vertical direction, and 30 m pixel of Landsat is a downscaled image of the aerial photograph. Moreover, field data collection can be easily conducted by deploying drone to cover inaccessible sample plots.
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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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Vásconez, Norma Lara, and Hernán Chamorro Sevilla. "Uso De Los Sensores Remotos En Mediciones Forestales." European Scientific Journal, ESJ 14, no. 15 (May 31, 2018): 58. http://dx.doi.org/10.19044/esj.2018.v14n15p58.
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To understand the use of remote sensors in forestry measurements, some of the most relevant definitions have been taken from a wide variety that currently exist, therefore, we will say that these generally play a predominant role in the Dasometry and that all The forest resource requires qualitative and quantitative information regarding the state of the forest and its evolution over time, with sampling that follows one of the existing methods. Historically, modern discipline arises with the invention of flight and the first photographs are obtained from a balloon in the years 1858 and 1859, in 1909 and on board the airplane the first photographic observation is acquired. The first aerial camera was developed in 1915 by J.T.C. Moore, starting the interesting way forward in the techniques of aerial photography using modified combat aircraft giving way to what was called systematic aerial photography in the late 50s. The development on a global scale of the first artificial satellites, allowed remote sensing in the middle of the 20th century on board the first satellite placed in orbit is that of the TYROS series in 1960 by NASA, becoming the pioneer in missions of meteorological observation, which also led to the appearance of satellite image processing, using mathematical procedures such as the Fourier transform. During the 70s missions were promoted with the objective of exploring the solar system and the moon; giving rise to the first spatial photographs taken by Alan B. Shepard rudimentary, Subsequently, Apollo-9 was used for the first multi-spectral experiment in which 4 Hasselblad cameras with different filters were installed. On July 23, 1972, the Landsat project appeared with the launch of the first satellite of the ERTS series (Earth Resources Technology Satellite). Google Earth in the 21st century, introduces online web services making remote sensing accessible to all audiences, with many techniques and processes that allow an image of the earth's surface to be obtained remotely captured by remote sensors located on satellites or airplanes that gather the spectral and spatial relations of objects. Interferometric radar synthetic aperture They are used to producing accurate digital models of large areas of land. LiDAR(An acronym for the English Light Detection and Ranging) is a monochrome active sensor, its mode of operation consists of measuring the distance between the sensor and the target. It is less expensive compared to manual inventory is multi-purpose, allows a complete survey of the study area, is more efficient than photogrammetry. The multi-spectral acquisition is based on the collection and analysis of areas or objects that emit or reflect radiation at a higher level than nearby objects. The quality of the information collected remotely, once the correction of errors through georeferencing with the help of specialized programs, will depend on their resolutions: spatial, spectral, radiometric and temporal.
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Ndalila, Mercy N., Grant J. Williamson, and David M. J. S. Bowman. "Geographic Patterns of Fire Severity Following an Extreme Eucalyptus Forest Fire in Southern Australia: 2013 Forcett-Dunalley Fire." Fire 1, no. 3 (October 22, 2018): 40. http://dx.doi.org/10.3390/fire1030040.
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Fire severity is an important characteristic of fire regimes; however, global assessments of fire regimes typically focus more on fire frequency and burnt area. Our objective in this case study is to use multiple lines of evidence to understand fire severity and intensity patterns and their environmental correlates in the extreme 2013 Forcett-Dunalley fire in southeast Tasmania, Australia. We use maximum likelihood classification of aerial photography, and fire behavior equations, to report on fire severity and intensity patterns, and compare the performance of multiple thresholds of the normalised burn ratio (dNBR) and normalized difference vegetation index (dNDVI) (from pre- and post-fire Landsat 7 images) against classified aerial photography. We investigate how vegetation, topography, and fire weather, and therefore intensity, influenced fire severity patterns. According to the aerial photographic classification, the fire burnt 25,950 ha of which 5% burnt at low severities, 17% at medium severity, 32% at high severity, 23% at very high severities, while 22% contained unburnt patches. Generalized linear modelling revealed that fire severity was strongly influenced by slope angle, aspect, and interactions between vegetation type and fire weather (FFDI) ranging from moderate (12) to catastrophic (>90). Extreme fire weather, which occurred in 2% of the total fire duration of the fire (16 days), caused the fire to burn nearly half (46%) of the total area of the fireground and resulted in modelled extreme fireline intensities among all vegetation types, including an inferred peak of 68,000 kW·m−1 in dry forest. The best satellite-based severity map was the site-specific dNBR (45% congruence with aerial photography) showing dNBR potential in Eucalyptus forests, but the reliability of this approach must be assessed using aerial photography, and/or ground assessment.
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ΑΣΤΑΡΑΣ, Θ., Δ. ΟΙΚΟΝΟΜΙΔΗΣ, and Α. ΜΟΥΡΑΤΙΔΗΣ. "Η συμβολή των δορυφορικών πολυφασματικών εικόνων στη Γεωμορφολογία, από τη δεκαετία του 70 (δορυφόροι LANDSAT) μέχρι σήμερα (δορυφόροι IKONOS, QuickBird). Παραδείγματα από την Ελλάδα." Bulletin of the Geological Society of Greece 38 (September 10, 2005): 157. http://dx.doi.org/10.12681/bgsg.18435.
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This paper describes initially the availability of multispectral satellite images, from the launch of the first Earth Resources Satellites (Landsat series), with medium resolution capabilities (80m), to the launch of the contemporary satellites (QuickBird, 2001), with very high resolution capabilities (60cm). It reviews researches, concerning the visual and digital image analyses of the LANDSAT series, SPOT, 1RS, TERRA and QuickBird satellite images that have been carried out during the last 20 years in the Department of Physical and Environmental Geography, School of Geology, Aristotle University of Thessaloniki. These researches are of geomorphological-geological interest and involve applications in various areas of Greece. In particular, practical examples are provided, concerning the detection and delineation of landslides in Macedonia and Epirus Provinces, the detection and classification of geomorphological units (land systems) in Peloponnesos, Thrace, Macedonia and Santorini areas and the analysis of drainage network in Central Macedonia Province with emphasis in the delineation of severe erosional phenomena. Reason for this review paper, is the contemporary use of Digital Elevation Models (DEMs) with 10-30 m accuracy, from the Shuttle Radar Topography Mission (SRTM / 2000) and their contribution, along with the high resolution satellite images, (from TERRA, QuickBird, etc), in the 3-D visualization of the Earths' relief. In particular, the use of 3-D satellite images will assist geoscientists and especially geomorphologists, to study the Earths' relief and its' evolution, more quickly, with better accuracy and at lower cost, compared with aerial photographs and 2-D satellite images, which have been used during the last 20 years.
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Salama, R. B., I. Tapley, T. Ishii, and G. Hawkes. "Identification of areas of recharge and discharge using Landsat-TM satellite imagery and aerial photography mapping techniques." Journal of Hydrology 162, no. 1-2 (October 1994): 119–41. http://dx.doi.org/10.1016/0022-1694(94)90007-8.
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Casassa, Gino, Katrine Smith, Andrés Rivera, José Araos, Michael Schnirch, and Christoph Schneider. "Inventory of glaciers in isla Riesco, Patagonia, Chile, based on aerial photography and satellite imagery." Annals of Glaciology 34 (2002): 373–78. http://dx.doi.org/10.3189/172756402781817671.
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AbstractA glacier inventory for península Córdova, isla Riesco, Chilean Patagonia (53°14’ S, 73°00’W), has been compiled based on stereoscopic interpretation of aerial photographs of March and December 1984 and 1:100 000 topographic maps. Three small icefields comprising 33 glacier outlets, in addition to 12 small separate glaciers, have been identified, with a total area of 57 km2. Glaciers are located on mountain peaks with a maximum altitude of 1183 mand a lowermost elevation of 100 m. All glaciers terminate on land, except for three glaciers calving into small fresh-water lakes. A Landsat Thematic Mapper (TM) image of 6 October 1986 has been rectified and analyzed using a supervised classification to estimate snow- and glacier-covered surfaces. Glacier-area data derived from satellite-image analyses have been adjusted at península Córdova using photo-interpreted data, and extrapolated to estimate a glacier area of 215 ±40km2 for all of isla Riesco. The presence of trimlines and moraines beyond the present position of the glaciers indicates a generalized retreat from a maximum neoglacial position at península Córdova, most probably as a result of regional warming and precipitation decrease observed during the last century.
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Harvey, Kylie R., and Greg J. E. Hill. "Mapping the nesting habitats of saltwater crocodiles (Crocodylus porosus) in Melacca Swamp and the Adelaide River wetlands, Northern Territory: an approach using remote sensing and GIS." Wildlife Research 30, no. 4 (2003): 365. http://dx.doi.org/10.1071/wr00008.
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The utility of integrating remotely sensed data and other spatial information in a geographical information system (GIS) to model habitat suitability for nesting by saltwater crocodiles (Crocodylus porosus) was investigated in this study. The study areas, Melacca Swamp and the Adelaide River wetlands, are located 50 km east of Darwin, Northern Territory, and encompass areas of suitable nesting habitat for C. porosus. Melacca Swamp is a highly productive nesting area and is managed as a conservation reserve to protect its nesting habitat. Landsat TM, SPOT satellite imagery and large-scale colour aerial photography were evaluated for their utility in mapping habitats preferred for nesting by C. porosus within Melacca Swamp. Satellite imagery was capable of identifying generalised habitat classes used for nesting (e.g. open swamp with emergent trees). However, it was only with aerial photography that habitats could be discerned (e.g. sedges with scattered Melaleuca trees). Spatial information derived from satellite imagery and other sources was integrated in a GIS to model potentially suitable nesting habitat along the Adelaide River. This methodology effectively identified known preferred nesting areas of C. porosus on the basis of the analysis of environmental parameters (i.e. distance to water, vegetation type) that have an influence on selection of nesting habitat. The findings of this research demonstrate the utility of remote sensing and GIS for mapping nesting habitat of C. porosus at a range of scales and provide guidelines for application of the approaches used at the regional or State level.
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Drury, S. A. "SPOT image data as an aid to structural mapping in the southern Aravalli Hills of Rajasthan, India." Geological Magazine 127, no. 3 (May 1990): 195–207. http://dx.doi.org/10.1017/s0016756800014485.
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AbstractThe 10 to 20 m resolution of SPOT image data, together with their potential for stereoscopic viewing, provides an excellent base for geological mapping inremote and rugged terrain that is akin to high-level aerial photographs. Their large format (60 × 60 km) also gives the advantage of synoptic coverage that ranks with images from the Landsat series of satellites. Use of stereo pairs of single-band SPOT images has enabled some revision of existing geological maps of the southern Aravalli Hills in Rajasthan at a scale of 1:100000, and has added significantly to knowledge of their complex mid-Proterozoic structure. In particular, many possibly early low-angled faults have been discovered, together with the tectonic nature of a major terrain boundary and much detail of intricate structures has been added in the more remote areas. The potentialfor lithological discrimination of multispectral SPOT data is severely limited by its restricted coverage of geologically important spectral features, and it is far surpassed by that of Landsat Thematic Mapper data, which would have been capable of more comprehensive lithofacies reconnaissance, had they been available.
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Dietler, Dominik, Andrea Farnham, Kees de Hoogh, and Mirko S. Winkler. "Quantification of Annual Settlement Growth in Rural Mining Areas Using Machine Learning." Remote Sensing 12, no. 2 (January 9, 2020): 235. http://dx.doi.org/10.3390/rs12020235.
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Studies on annual settlement growth have mainly focused on larger cities or incorporated data rarely available in, or applicable to, sparsely populated areas in sub-Saharan Africa, such as aerial photography or night-time light data. The aim of the present study is to quantify settlement growth in rural communities in Burkina Faso affected by industrial mining, which often experience substantial in-migration. A multi-annual training dataset was created using historic Google Earth imagery. Support vector machine classifiers were fitted on Landsat scenes to produce annual land use classification maps. Post-classification steps included visual quality assessments, majority voting of scenes of the same year and temporal consistency correction. Overall accuracy in the four studied scenes ranged between 58.5% and 95.1%. Arid conditions and limited availability of Google Earth imagery negatively affected classification accuracy. Humid study sites, where training data could be generated in proximity to the areas of interest, showed the highest classification accuracies. Overall, by relying solely on freely and globally available imagery, the proposed methodology is a promising approach for tracking fast-paced population dynamics in rural areas where population data is scarce. With the growing availability of longitudinal high-resolution imagery, including data from the Sentinel satellites, the potential applications of the methodology presented will further increase in the future.
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Johnston, RM, and MM Barson. "Remote sensing of Australian wetlands: An evaluation of Landsat TM data for inventory and classification." Marine and Freshwater Research 44, no. 2 (1993): 235. http://dx.doi.org/10.1071/mf9930235.
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This study aimed to develop simple remote-sensing techniques suitable for mapping and monitoring wetlands, using Landsat TM imagery of inland wetland sites in Victoria and New South Wales. A range of classification methods was examined in attempts to map the location and extent of wetlands and their vegetation types. Multi-temporal imagery (winter/spring and summer) was used to display seasonal variability in water regime and vegetation status. Simple density slicing of the mid-infrared band (TM5) from imagery taken during wet conditions was useful for mapping the location and extent of inundated areas. None of the classification methods tested reproduced field maps of dominant vegetation species; however, density slicing of multi-temporal imagery produced classes based on seasonal variation in water regime and vegetation status that are useful for reconnaissance mapping and for examining variability in previously mapped units. Satellite imagery is unlikely to replace aerial photography for detailed mapping of wetland vegetation types, particularly where ecological gradients are steep, as in many riverine systems. However, it has much to offer in monitoring changes in water regime and in reconnaissance mapping at regional scales.
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Falkowski, Michael J., Michael A. Wulder, Joanne C. White, and Mark D. Gillis. "Supporting large-area, sample-based forest inventories with very high spatial resolution satellite imagery." Progress in Physical Geography: Earth and Environment 33, no. 3 (June 2009): 403–23. http://dx.doi.org/10.1177/0309133309342643.
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Information needs associated with forest management and reporting requires data with a steadily increasing level of detail and temporal frequency. Remote sensing satellites commonly used for forest monitoring (eg, Landsat, SPOT) typically collect imagery with sufficient temporal frequency, but lack the requisite spatial and categorical detail for some forest inventory information needs. Aerial photography remains a principal data source for forest inventory; however, information extraction is primarily accomplished through manual processes. The spatial, categorical, and temporal information requirements of large-area forest inventories can be met through sample-based data collection. Opportunities exist for very high spatial resolution (VHSR; ie, <1 m) remotely sensed imagery to augment traditional data sources for large-area, sample-based forest inventories, especially for inventory update. In this paper, we synthesize the state-of-the-art in the use of VHSR remotely sensed imagery for forest inventory and monitoring. Based upon this review, we develop a framework for updating a sample-based, large-area forest inventory that incorporates VHSR imagery. Using the information needs of the Canadian National Forest Inventory (NFI) for context, we demonstrate the potential capabilities of VHSR imagery in four phases of the forest inventory update process: stand delineation, automated attribution, manual interpretation, and indirect attribute modelling. Although designed to support the information needs of the Canadian NFI, the framework presented herein could be adapted to support other sample-based, large-area forest monitoring initiatives.
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Quincey, D. J., R. M. Lucas, S. D. Richardson, N. F. Glasser, M. J. Hambrey, and J. M. Reynolds. "Optical remote sensing techniques in high-mountain environments: application to glacial hazards." Progress in Physical Geography: Earth and Environment 29, no. 4 (December 2005): 475–505. http://dx.doi.org/10.1191/0309133305pp456ra.
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Remote sensing studies have shown that glaciers and their proximal environments exhibit unique temporal, spatial and spectral characteristics that can be analysed to better quantify glacial hazard potential. In this review, the optical remote sensing data sources available to glacial hazard assessors are considered and the range of information on glacial environments that can be derived is analysed. The review shows that the integration of a variety of data sources can provide geoscientists with information regarding glacial lakes and lake development, glacier dynamics, avalanche sources and ice-marginal fluctuations. Such data can be used to complement and, in many cases, improve field-based glacial hazard assessments. The review concludes that aerial photography still remains the main source of data for measuring a number of glacier characteristics, but that fine to moderate spatial resolution satellite sensors (e.g., ASTER, SPOT 5 HRVIR, Landsat ETM) also provide useful information that can be used to support the assessment of hazards in high-mountain glacierized terrain.
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Shahgedanova, M., G. Nosenko, S. Kutuzov, O. Rototaeva, and T. Khromova. "Deglaciation of the Caucasus Mountains, Russia/Georgia, in the 21st century observed with ASTER satellite imagery and aerial photography." Cryosphere 8, no. 6 (December 16, 2014): 2367–79. http://dx.doi.org/10.5194/tc-8-2367-2014.
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Abstract. Changes in the map area of 498 glaciers located on the Main Caucasus ridge (MCR) and on Mt. Elbrus in the Greater Caucasus Mountains (Russia and Georgia) were assessed using multispectral ASTER and panchromatic Landsat imagery with 15 m spatial resolution in 1999/2001 and 2010/2012. Changes in recession rates of glacier snouts between 1987–2001 and 2001–2010 were investigated using aerial photography and ASTER imagery for a sub-sample of 44 glaciers. In total, glacier area decreased by 4.7 ± 2.1% or 19.2 ± 8.7 km2 from 407.3 ± 5.4 km2 to 388.1 ± 5.2 km2. Glaciers located in the central and western MCR lost 13.4 ± 7.3 km2 (4.7 ± 2.5%) in total or 8.5 km2 (5.0 ± 2.4%) and 4.9 km2 (4.1 ± 2.7%) respectively. Glaciers on Mt. Elbrus, although located at higher elevations, lost 5.8 ± 1.4 km2 (4.9 ± 1.2%) of their total area. The recession rates of valley glacier termini increased between 1987–2000/01 and 2000/01–2010 (2000 for the western MCR and 2001 for the central MCR and Mt.~Elbrus) from 3.8 ± 0.8, 3.2 ± 0.9 and 8.3 ± 0.8 m yr−1 to 11.9 ± 1.1, 8.7 ± 1.1 and 14.1 ± 1.1 m yr−1 in the central and western MCR and on Mt. Elbrus respectively. The highest rate of increase in glacier termini retreat was registered on the southern slope of the central MCR where it has tripled. A positive trend in summer temperatures forced glacier recession, and strong positive temperature anomalies in 1998, 2006, and 2010 contributed to the enhanced loss of ice. An increase in accumulation season precipitation observed in the northern MCR since the mid-1980s has not compensated for the effects of summer warming while the negative precipitation anomalies, observed on the southern slope of the central MCR in the 1990s, resulted in stronger glacier wastage.
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Shahgedanova, M., G. Nosenko, S. Kutuzov, O. Rototaeva, and T. Khromova. "Deglaciation of the Caucasus Mountains, Russia/Georgia, in the 21st century observed with ASTER satellite imagery and aerial photography." Cryosphere Discussions 8, no. 4 (July 25, 2014): 4159–94. http://dx.doi.org/10.5194/tcd-8-4159-2014.
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Abstract. Changes in map area of 498 glaciers located in the Main Caucasus Ridge (MCR) and on Mt. Elbrus in the Greater Caucasus Mountains (Russia and Georgia) were assessed using multispectral ASTER and panchromatic Landsat imagery with 15 m spatial resolution from 1999–2001 and 2010–2012. Changes in recession rates of glacier snouts between 1987–2001 and 2001–2010 were investigated using aerial photography and ASTER imagery for a sub-sample of glaciers. In total, glacier area declined by 4.7 ± 1.6% or 19.24 km2. Glaciers located in the central and western MCR lost 13.4 km2 (4.6 ± 1.8%) in total or 8.56 km2 (5.0 ± 1.8%) and 4.87 km2 (4.1 ± 1.9%) respectively. Glaciers on Mt. Elbrus, although located at higher elevations, lost 5.8 km2 (4.9 ± 0.7%) of their total area. The recession rates of valley glacier termini increased between 1987–2000/01 and 2010 from 3.8 ± 0.8 m a−1, 3.2 ± 0.9 m a−1 and 8.3 ± 0.8 m a−1 to 11.9 ± 1.1 m a−1, 8.7 ± 1.1 m a−1 and 14.1 ± 1.1 m a−1 in the central and western MCR and on Mt. Elbrus respectively. The highest rate of increase in glacier termini retreat was registered on the southern slope of the central MCR where it has tripled. A positive trend in summer temperatures forced glacier recession and strong positive temperature anomalies of 1998, 2006, and 2010 contributed to the enhanced loss of ice. An increase in accumulation season precipitation observed in the northern MCR since the mid-1980s has not compensated for the effects of summer warming while the negative precipitation anomalies, observed on the southern slope of the central MCR in the 1990s, resulted in stronger glacier wastage.
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Harvey, K. R., and G. J. E. Hill. "Vegetation mapping of a tropical freshwater swamp in the Northern Territory, Australia: A comparison of aerial photography, Landsat TM and SPOT satellite imagery." International Journal of Remote Sensing 22, no. 15 (January 2001): 2911–25. http://dx.doi.org/10.1080/01431160119174.
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Coops, Nicholas, Antoine Delahaye, and Eddy Pook. "Estimation of Eucalypt Forest Leaf Area Index on the South Coast of New South Wales using Landsat MSS Data." Australian Journal of Botany 45, no. 5 (1997): 757. http://dx.doi.org/10.1071/bt96021.
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Research over the last decade has shown that regional estimation of Leaf Area Index (LAI) is possible using the ratio of red and near infrared radiation derived from satellite or airborne sensors. At landscape levels, however, this relationship has been more difficult to establish due to (i) logistic difficulties in measuring seasonal variation in LAI across the landscape over an extended period of time and (ii) difficulties in establishing the effect of understorey, canopy closure, and soil on the spectral radiation at fine spatial resolutions (< 100 m). This paper examines the first issue by utilising a temporal sequence of LAI data of a Eucalyptus mixed hardwood forest (E. maculata Hook., E. paniculata Sm., E. globoidea Blakely, E. pilularis Sm., E. sieberi L.Johnson) in south-eastern New South Wales and comparing it to historical Landsat Multi-Spectral Scanner (MSS) data covering a 9 year period. Field LAI was compared to the Normalised Difference Vegetation Index (NDVI) and the Simple Ratio (SR) derived from the MSS data. Linear relationships were shown to be appropriate to relate both transformations to the LAI data with r2 -values of 0.71 and 0.53 respectively. Using the NDVI relationship, LAI values were estimated along a transect originating from the monitoring site and these were compared to percentage canopy cover values derived from aerial photography.
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Stefouli, M., and P. Tsombos. "IDENTIFICATION AND MONITORING OF FRESH WATER OUTFLOWS IN COASTAL AREAS: PILOT STUDY ON PSAHNA AREA / EVIA ISLAND - GREECE." Bulletin of the Geological Society of Greece 36, no. 2 (July 23, 2018): 928. http://dx.doi.org/10.12681/bgsg.16894.
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Earth systems are interrelated in complex ways, which are inadequately understood. An improved understanding of these systems is necessary in order to develop effective policies for hydrologie management. Furthermore, the results should be communicated to decision-makers. The aim of the work has been to evaluate the applicability of the use of digital multi-temporal Landsat 5 / 7 images and aerial photography, for the mapping of local scale fresh water outflows, geological features and monitoring changes of the water outflows in coastal areas. "Psahna" map sheet (HAGS, 1977) in the Central part of Evia island in Greece has been used as pilot project area of study. Processing techniques have been applied for the: • Application of integrated image processing / GIS vector data techniques. • Image integration and creation of data fusion image products. • Automatic raster to vector conversion techniques, for the identification of the areal extent of changes in conditions of the water outflows through time and final map updating. The contribution of the remotely sensed data to the geologic / géomorphologie mapping and identification of changes of fresh water outflow through time is indicated with the processed satellite imagery for the pilot project area. Generally, the use of the remotely sensed images in map updating lies in the fact, that various hydrologie and geologic features can be mapped quickly for large areas while any temporal changes can be identified and evaluated. The satellite data seem to be a cost-effective solution for the map updating procedure. The cost to processing functions is well justifiable to a geologic / hydro-geologic-hydrologic map updating procedure. The system provides monitoring and feedback at appropriate spatial scales, using high resolution satellite remote sensing data and state of the art GIS techniques.
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Barrs, HD, and SA Prathapar. "An inexpensive and effective basis for monitoring rice areas using GIS and remote sensing." Australian Journal of Experimental Agriculture 34, no. 7 (1994): 1079. http://dx.doi.org/10.1071/ea9941079.
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To ensure orderly, planned rice production, and to meet environmental constraints on the location of rice in the landscape, there is a need to locate and measure the area of rice plantings by paddock and by farm. Traditionally, rice areas have been estimated from manual measurements taken from aerial photography: overall, an expensive and time-consuming approach. In a pilot study covering 5 seasons on an area of 6 by 6.25 km containing 160 paddocks in 22 farms, we have found that it is possible to locate rice areas accurately, to determine their size, and to classify the vigour of the crop. Information is transferred into a geographic information system from classified satellite imagery using Landsat Thematic Mapper bands 3, 4, and 5 and then processed with a simple rule to distinguish rice rapidly from other crops. Furthermore, the classification categorises rice within each paddock into 3 statistically distinct groups of poor, medium, or good crop vigour. Total rice area and area of each rice class are computed for each rice paddock. Paddock data are combined to give corresponding values for each farm and for the entire study area. This information could be useful for forecasting rice yields in the current season and for the management of paddocks for more uniform and higher yields in subsequent seasons. The procedures used require inexpensive software and are largely automated since they include unsupervised clustering. The need for special skills is thereby minimised, making the transfer of the technology to interested parties quite straightforward. Over the 5 seasons, all paddocks growing rice were correctly identified and only 2 non-rice paddocks wrongly identified as growing rice.
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Deguchi, C., and S. Sugio. "Estimations for Percentage of Impervious Area by the Use of Satellite Remote Sensing Imagery." Water Science and Technology 29, no. 1-2 (January 1, 1994): 135–44. http://dx.doi.org/10.2166/wst.1994.0659.
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This study aims to evaluate the applicability of satellite imagery in estimating the percentage of impervious area in urbanized areas. Two methods of estimation are proposed and applied to a small urbanized watershed in Japan. The area is considered under two different cases of subdivision; i.e., 14 zones and 17 zones. The satellite imageries of LANDSAT-MSS (Multi-Spectral Scanner) in 1984, MOS-MESSR(Multi-spectral Electronic Self-Scanning Radiometer) in 1988 and SPOT-HRV(High Resolution Visible) in 1988 are classified. The percentage of imperviousness in 17 zones is estimated by using these classification results. These values are compared with the ones obtained from the aerial photographs. The percent imperviousness derived from the imagery agrees well with those derived from aerial photographs. The estimation errors evaluated are less than 10%, the same as those obtained from aerial photographs.
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Gardiner, DB, GJ Tupper, and GS Dundeon. "A Quantitative Appraisal of Woody Shrub Encroachment in Western New South Wales." Rangeland Journal 20, no. 1 (1998): 26. http://dx.doi.org/10.1071/rj9980026.
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Landsat Multispectral Scanner (MSS) digital imagery was used to estimate the distribution, density and change in woody shrub cover over time in western New South Wales. The purpose of the project was to derive maps of woody cover which can be used as a basis for regional planning and property planning. Assessment of woody vegetation cover using satellite imagery enables regions which are more susceptible to shrub encroachment to be targeted for control strategies. Dry season images which had minimal green vegetation were used, because the spectral signatures of scrubby ground cover interfered with the proper classification of woody vegetation. For each region, multidate imagery was classified using a pixel unmixing algorithm to derive data sets which showed woody canopy cover. These data were then rescaled to percentage values using aerial photography sampled throughout each region. A geographic information system (GIS) was used to derive changes in woody cover between both dates and to present the data in map form. Most current woody cover in the study area occurs at less than 20% cover, whilst higher levels (40 to 80%) occur in the eastern parts of the Louth and Barnato regions. At least 20,3 10 km2 of the 120,000 km2 study area is already affected by woody vegetation cover levels of greater than 40%, which significantly reduces carrying capacity and pastoral productivity. Changes in woody cover over a 10 to 20 year period were varied. Approximately 24% (26,041 km2) was relatively stable, whilst 20% of the Barnato region had moderate decreases (1 1 to 30%) due to wildfires, and increases of 11 to 30% cover occurred on 'hard red' soils in the east. Emerging woody vegetation of less than 10% cover occurred over 1816 km2 of Sandplains and Stony Lowlands in the Louth and Barnato regions, whilst woody vegetation levels of more than 40% cover occurred in the Barnato region. Considerable 'infilling' of previously unwooded areas was noted for regions which already had high levels of woody cover. A minimal amount of prescribed clearing was apparent from the change data, which suggests that effective control of shrubs is difficult to achieve and that future scenarios will see continued encroachment. The findings suggest that the southern Louth and Barnato regions are most at risk of further shrub encroachment, and that these areas need to be targeted for shrub control. The data provide a quantitative estimate of woody shrub cover which is useful for economic assessments, as well as providing an information base upon which woody shrub management strategies can be developed. Key words: Landsat Multispectral Scanner, remote sensing, geographic information system, change detection, rangeland, monitoring, land cover.
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TOBORE, A. O., G. OYERINDE, B. A. SENJOBI, and T. O. OGUNDIYI. "POTENTIALS AND CHARACTERISTICS OF LANDSAT IMAGERY IN RELATION TO LAND USE /COVER IN OKITIPUPA METROPOLIS, ONDO STATE, NIGERIA." Journal of Agricultural Science and Environment 19, no. 1 (October 5, 2020): 150–58. http://dx.doi.org/10.51406/jagse.v19i1.2021.
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Landsat satellite imagery plays a crucial role in providing information on land use/cover modifications on local, regional, and global scales, especially where aerial photographs are missing. Monitoring land-use changes from past to present tends to be time-consuming especially when dealing with ground-truth information. Determining the past and current land-use change on Earth's surface using Landsat imagery tends to be effective and efficient when high-resolution imagery is unavailable. This study employed the use of Landsat satellite imagery to assess the past and present land use/cover using supervised classification and Normalized Difference Vegetation Index (NDVI). The result of the supervised classification land use/cover showed that forest cover and woodland undergo rapid loss, while farmland, wetland, built-up, and waterbodies tend to experience gradual loss. The NDVI demonstrated that farmland and forest cover was the most affected land use/cover. Hence, land use/cover of the study area is affected by human activities, such as intensive farming, population size, and deforestation.
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Medvedev, Andrey, Arseny Kudikov, Natalia Telnova, Olga Tutubalina, Elena Golubeva, and Mikhail Zimin. "Multiscale assessment of northern forest characteristics based on ultra-high resolution data." Abstracts of the ICA 1 (July 15, 2019): 1. http://dx.doi.org/10.5194/ica-abs-1-246-2019.
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<p><strong>Abstract.</strong> The algorithms for quantitative estimates of various structural and functional parameters of forest ecosystems, particularly boreal forests, on high resolution remote sensing data are actively developing since the mid-2000s. For monitoring of forest ecosystems located at the Northern limit of distribution, effective not only lidar data but also the optical data obtained by unmanned aerial vehicles (UAV’s) with ultra-low altitude photography and derived products resulting from modern algorithms for the photogrammetric processing.</p><p>High-detail remote sensing from UAV’s is a key level of monitoring of Northern forests at a large-scale level, ensuring the correct transition from sub - satellite ground-based studies to thematic products obtained from multi-time Hyper-and multispectral data of medium and relatively high resolution (MODIS, LANDSAT, Sentinel-2).</p><p>When planning and conducting specific case studies based on UAV data, special attention should be paid to the justification of the survey methodology. In particular, the choice of a strictly defined high-altitude echelon of the survey determines the recognition of the objects of study and the possibility of reliable determination of its properties and features. To study the parameters of forest ecosystems at the level of individual trees and at the level of forest plantations, we selected two different-height echelons of survey from ultra-low altitudes: from 50 m, which allowed us to obtain ultra-high-detailed data for each sample area provided by detailed ground-based studies with sub-tree account, and from 100 m-to obtain derived characteristics of forest communities within the area equivalent to 3 pixels of thematic MODIS products with a spatial resolution of 250 m. The data of optical survey with UAV were obtained in July 2018 for 22 plots located in the central part of the Kola Peninsula and representative of different types of North taiga stands and their dynamics under climate change.</p><p>At the stage of preprocessing images were obtained dense point clouds, characterizing both vertical and horizontal structure of stands. Digital terrain and terrain models and tree canopy models were obtained after cloud filtering and classification. Algorithms of automated segmentation and classification have been developed and tested to obtain such characteristics of stands as the height of individual trees, the area of crown projections, the projective cover of the tree-shrub layer. The obtained characteristics are aggregated by cells of a regular network with the dimension corresponding to the spatial resolution of Sentinel-2 and Landsat-8 data.</p><p>The main results of the works are digital spatial datasets for 22 sample plots: raw data with very high resolution imagery (optical images with very high resolution, dense point clouds, RGB-orthophoto) and create based on a thematic derivative products (digital terrain model, topography, tree canopy cover; map of the heights and projections of the crowns of trees, percent cover of tree and shrub vegetation).</p>
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Manson, F. J., N. R. Loneragan, I. M. McLeod, and R. A. Kenyon. "Assessing techniques for estimating the extent of mangroves: topographic maps, aerial photographs and Landsat TM images." Marine and Freshwater Research 52, no. 5 (2001): 787. http://dx.doi.org/10.1071/mf00052.
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Coastal habitats are critical to the sustained production of many fisheries. It is important, therefore, that fishery managers obtain accurate estimates of the extent of these habitats. This study investigated three methods of estimating the linear extent and area of mangroves (commercially available topographic data, aerial photographs and Landsat Thematic Mapper satellite imagery) in two regions in northern Australia: the Joseph Bonaparte Gulf (in particular, the Berkeley and Lyne Rivers) with typically narrow fringes of mangroves (<50 m wide), and the Embley River on Cape York Peninsula,with much broader mangrove stands (50–1000 m wide). Ground-truthing verified that aerial photographs provided the most accurate estimates of extents of mangroves in all rivers,because of their high spatial resolution (2 m). Landsat Thematic Mapper imagery gave good estimates of the area of habitats, but, because of the 30 m pixel resolution, it underestimated the linear extent in places where the mangrove fringe was narrow. Topographic data gave good estimates of the extent of mangroves where the forests were more extensive and less linear in shape, but were very poor otherwise at this scale. These findings have implications for the use of remote sensing techniques in ecological studies in these regions.
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HONEY-ROSÉS, JORDI, JOSÉ LÓPEZ-GARCÍA, EDUARDO RENDÓN-SALINAS, ARMANDO PERALTA-HIGUERA, and CARLOS GALINDO-LEAL. "To pay or not to pay? Monitoring performance and enforcing conditionality when paying for forest conservation in Mexico." Environmental Conservation 36, no. 2 (June 2009): 120–28. http://dx.doi.org/10.1017/s0376892909990063.
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SUMMARYPaying landowners to conserve forests is a promising new strategy to protect biodiversity and ecosystem services. However to succeed with this approach, programme managers need reliable monitoring data to make informed payment decisions. This includes withholding payment from landowners who do not meet conservation objectives. The monitoring method used for the Monarch Butterfly Conservation Fund compared aerial photographs and conducted field sampling to identify forest changes. The comparison of aerial photographs showed that 161 hectares of forest were degraded in the central core zone of the Monarch Butterfly Biosphere Reserve in Mexico between 2001 and 2003. As a result, payment was withheld from one of 13 landowners. Analysis of high resolution (0.6 m) digital aerial photographs did not detect finer scale changes, despite obtaining an average pixel resolution 1000 times greater than Landsat satellite imagery. This suggests that current payment for ecosystem services programmes are underestimating environmental change and overpaying non-compliant participants. In addition, selecting a decision rule to enforce payment conditionality raised new questions about how much ecosystem degradation should be permitted before withholding payment. Sound decisions about withholding payment cannot be developed until the marginal value of ecosystem services is better understood. Until then, payment thresholds can be based on specific policy objectives.
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Stähli, Manfred, Jesko Schaper, and Andreas Papritz. "Towards a snow-depth distribution model in a heterogeneous subalpine forest using a Landsat TM image and an aerial photograph." Annals of Glaciology 34 (2002): 65–70. http://dx.doi.org/10.3189/172756402781817923.
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AbstractFor landscapes with a complex topography and a heterogeneous forest mosaic it is not feasible to map the snow depth directly from optical satellite images. In this paper, an indirect method to predict the snow-depth distribution is presented and applied to a 0.7 km2 subalpine catchment in central Switzerland. The method consists of (a) a parsimonious linear regression model which includes the attributes of topography and vegetation indices (derived from a Landsat Thematic Mapper (TM) image) as explanatory variables, and (b) geostatistical interpolationtechniques. A previous analysis of the forest mosaic revealed two main scales showing up in the Landsat TM image and an aerial photograph. This discrepancy in scale was assumed to be the major reason why the vegetation indices derived from the Landsat TM image were only weak explanators of the snow-depth variation measured at 100–200 locations within the catchment. Surprisingly, the geostatistical interpolation (universal kriging) was not able to improve the prediction of the snow-depth distribution significantly. The residuals of the regression model showed hardly any spatial dependence for single snow-measurement dates.
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Wang, Yetang, Shugui Hou, and Yaping Liu. "Glacier changes in the Karlik Shan, eastern Tien Shan, during 1971/72–2001/02." Annals of Glaciology 50, no. 53 (2009): 39–45. http://dx.doi.org/10.3189/172756410790595877.
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AbstractGlacier changes in the Karlik Shan, eastern Tien Shan, from 1971/72 to 2001/02 were monitored in this study. Topographic maps of 1 : 50 000 scale based on aerial photographs from 1971/72 and satellite images (Landsat TM, Landsat ETM+ and ASTER) from 1992, 2001 and 2002 were used to map glacier extent through a process of manual digitizing. The total glacier area decreased by 5.3% from 1971/72 to 2001/02. The rate of glacier area shrinkage was 0.13% a–1 between 1972 and 1992, but it was 0.27% a–1 from 1992 to 2001/02, suggesting accelerated glacier retreat in recent decades. Glacier changes in the region are a response to summer temperature increase. Annual precipitation also showed an upward trend, but this could not compensate for the mass loss due to ablation.
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Mastelic, Toni, Josip Lorincz, Ivan Ivandic, and Matea Boban. "Aerial Imagery Based on Commercial Flights as Remote Sensing Platform." Sensors 20, no. 6 (March 17, 2020): 1658. http://dx.doi.org/10.3390/s20061658.
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Remote sensing is commonly performed via airborne platforms such as satellites, specialized aircraft, and unmanned aerial systems (UASs), which perform airborne photography using mounted cameras. However, they are limited by their coverage (UASs), irregular flyover frequency (aircraft), and/or low spatial resolution (satellites) due to their high altitude. In this paper, we examine the utilization of commercial flights as an airborne platform for remote sensing. Namely, we simulate a situation where all aircraft on commercial flights are equipped with a mounted camera used for airborne photography. The simulation is used to estimate coverage, the temporal and spatial resolution of aerial imagery acquired this way, as well as the storage capacity required for storing all imagery data. The results show that Europe is 83.28 percent covered with an average of one aerial photography every half an hour and a ground sampling distance of 0.96 meters per pixel. Capturing such imagery results in 20 million images or four petabytes of image data per day. More detailed results are given in the paper for separate countries/territories in Europe, individual commercial airlines and alliances, as well as three different cameras.
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Parece, Tammy, and James Campbell. "Comparing Urban Impervious Surface Identification Using Landsat and High Resolution Aerial Photography." Remote Sensing 5, no. 10 (October 10, 2013): 4942–60. http://dx.doi.org/10.3390/rs5104942.
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Bown, Francisca, Andrés Rivera, and César Acuña. "Recent glacier variations at the Aconcagua basin, central Chilean Andes." Annals of Glaciology 48 (2008): 43–48. http://dx.doi.org/10.3189/172756408784700572.
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AbstractThe majority of glaciers in central Chile have receded in recent decades, from >50m to only a few meters per year, mainly in response to an increase in the 0˚C isotherm altitude. The Aconcagua river basin (33˚ S) is one of the major glaciated basins in central Chile, with 121 km2 of ice in 2003. An earlier inventory using 1955 aerial photographs yielded a total surface area of 151 km2, implying a reduction in glacier area of 20% (0.63km2 a–1) over the 48 years. Photographic stereo models, high-resolution satellite images (Landsat, ASTER) and SRTM data have been used to delineate glacier basins. A focus on Glaciar Juncal Norte, one of the largest glaciers in the basin, allows a more detailed analysis of changes. The glacier has exhibited a smaller reduction (14%) between 1955 and 2006, and the resulting elevation changes over this smaller period are not significant. The above reduction rates are lower than in other glaciers of central Chile and Argentina. This trend emphasizes water runoff availability in a river where most of the water in the dry summers is generated by glaciers and snowpack, and where most of the superficial water rights are already allocated. Ongoing hydrological research including modelling of future water runoff will improve our understanding.
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Thomsen, H. H. "Photogrammetric and Satellite Mapping of the Margin of the Inland Ice, West Greenland." Annals of Glaciology 8 (1986): 164–67. http://dx.doi.org/10.1017/s0260305500001373.
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Glaciological investigations have been carried out in areas proposed for local hydro-power stations in Greenland, A mapping programme was set up, to provide data for mass balance and simulation of run-off, as well as glacier dynamics.Two types of glacier map have been produced, covering the margin of the Inland Ice: detailed photogrammetric maps, based on plotting from vertical aerial photographs and a new type of surface feature map, based on digitally-processed Landsat data. The photogrammetric maps, plotted on a scale of 1:25 000, include surface topography and surface features, such as crevasses, lakes, moraines etc. The surface feature maps, plotted on a scale of 1:100 000, show surface features related to ice and melt-water drainage, as well as subtle, topographic features, related to the subglacial topography.The maps have so far been used for preliminary delineation of drainage areas on the Inland Ice and for planning tracks of radio echo-soundings.
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Thomsen, H. H. "Photogrammetric and Satellite Mapping of the Margin of the Inland Ice, West Greenland." Annals of Glaciology 8 (1986): 164–67. http://dx.doi.org/10.3189/s0260305500001373.
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Glaciological investigations have been carried out in areas proposed for local hydro-power stations in Greenland, A mapping programme was set up, to provide data for mass balance and simulation of run-off, as well as glacier dynamics.Two types of glacier map have been produced, covering the margin of the Inland Ice: detailed photogrammetric maps, based on plotting from vertical aerial photographs and a new type of surface feature map, based on digitally-processed Landsat data. The photogrammetric maps, plotted on a scale of 1:25 000, include surface topography and surface features, such as crevasses, lakes, moraines etc. The surface feature maps, plotted on a scale of 1:100 000, show surface features related to ice and melt-water drainage, as well as subtle, topographic features, related to the subglacial topography.The maps have so far been used for preliminary delineation of drainage areas on the Inland Ice and for planning tracks of radio echo-soundings.
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Samani Majd, Amir M., Max P. Bleiweiss, Dave DuBois, and Manoj K. Shukla. "Estimation of the fractional canopy cover of pecan orchards using Landsat 5 satellite data, aerial imagery, and orchard floor photographs." International Journal of Remote Sensing 34, no. 16 (May 23, 2013): 5937–52. http://dx.doi.org/10.1080/01431161.2013.800951.
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LIMA, ZULEIDE MARIA CARVALHO, ADRIANO DE LIMA ALVES, VENERANDO EUSTÁQUIO AMARO, and HELENICE VITAL. "Evolução da Linha de Costa do Esporão de Galinhos (NE Brasil) Utilizando Fotografias Aéreas e Imagens Landsat TM." Pesquisas em Geociências 28, no. 2 (December 31, 2001): 497. http://dx.doi.org/10.22456/1807-9806.20324.
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Galinhos is one of many spits along the northern coast of Rio Grande do Norte state. Nowadays it has almost 10 km of extension in the E-W direction and medium width of 550 m. Sandy beaches, reefs, estuary, mangroves, lagoon, and dunes are the characteristic geomorphologic features. The modeling of these features is directly correlated with the united performance of waves, coastal current and winds, related with variations of the se level happened in the Quaternary. Aiming to monitoring the evolution of the coastline, it was used aerial photographs from 1954, 1967 and 1988 and satellite images from 1989 and 2000. After georeferred, the images were submitted to several techniques of digital processing, being applied synthesis techniques (dimensionality reduction) and emphasis of the information contained in the same ones, as: RGB colored compositions, index methods (NDWI), analysis for main components (PC’s) and space frequency filtering (directional filters). Each one of the six spectral bands (1-5 and 7) of the Landsat 5-TM and 7-ETM+ were submitted to contrast modifications of the histogram (lineal and no lineal contrast transformations). Among the applied processes, NDWI and the colored composition RGB 432 showed better results to the identification of the interface sea/earth. The application of directional filters allowed to observe submerged features, as sandwaves and photolineaments; the last one also observed in the aerial photographs, with direction NE-SW, which infers the existence of a paleo-channel, cutting the Galinhos spit, suggesting ancient system of island barrier developing for the current spit. The results show a ciclicity of erosional and accretionary processes, as well as the progress of the field of coastal dunes, located in the end East, burying the mangrove vegetation and silting up the tidal channel.
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Pârvu, Iuliana Maria, Iuliana Adriana Cuibac Picu, P. I. Dragomir, and Daniela Poli. "Urban Classification from Aerial and Satellite Images." Journal of Applied Engineering Sciences 10, no. 2 (December 1, 2020): 163–72. http://dx.doi.org/10.2478/jaes-2020-0024.
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AbstractWhen talking about land cover, we need to find a proper way to extract information from aerial or satellite images. In the field of photogrammetry, aerial images are generally acquired by optical sensors that deliver images in four bands (red, green, blue and near-infrared). Recent researches in this field demonstrated that for the image classification process is still place for improvement. From satellites are obtained multispectral images with more bands (e.g. Landsat 7/8 has 36 spectral bands). This paper will present the differences between these two types of images and the classification results using support-vector machine and maximum likelihood classifier. For the aerial and the satellite images we used different sets of classification classes and the two methods mentioned above to highlight the importance of choosing the classes and the classification method.
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Ha, Nam-Thang, Merilyn Manley-Harris, Tien-Dat Pham, and Ian Hawes. "Detecting Multi-Decadal Changes in Seagrass Cover in Tauranga Harbour, New Zealand, Using Landsat Imagery and Boosting Ensemble Classification Techniques." ISPRS International Journal of Geo-Information 10, no. 6 (May 31, 2021): 371. http://dx.doi.org/10.3390/ijgi10060371.
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Seagrass provides a wide range of essential ecosystem services, supports climate change mitigation, and contributes to blue carbon sequestration. This resource, however, is undergoing significant declines across the globe, and there is an urgent need to develop change detection techniques appropriate to the scale of loss and applicable to the complex coastal marine environment. Our work aimed to develop remote-sensing-based techniques for detection of changes between 1990 and 2019 in the area of seagrass meadows in Tauranga Harbour, New Zealand. Four state-of-the-art machine-learning models, Random Forest (RF), Support Vector Machine (SVM), Extreme Gradient Boost (XGB), and CatBoost (CB), were evaluated for classification of seagrass cover (presence/absence) in a Landsat 8 image from 2019, using near-concurrent Ground-Truth Points (GTPs). We then used the most accurate one of these models, CB, with historic Landsat imagery supported by classified aerial photographs for an estimation of change in cover over time. The CB model produced the highest accuracies (precision, recall, F1 scores of 0.94, 0.96, and 0.95 respectively). We were able to use Landsat imagery to document the trajectory and spatial distribution of an approximately 50% reduction in seagrass area from 2237 ha to 1184 ha between the years 1990–2019. Our illustration of change detection of seagrass in Tauranga Harbour suggests that machine-learning techniques, coupled with historic satellite imagery, offers potential for evaluation of historic as well as ongoing seagrass dynamics.
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Hartcher, Michael G., and Rezaul K. Chowdhury. "An alternative method for estimating total impervious area in catchments using high-resolution colour aerial photography." Water Practice and Technology 12, no. 2 (June 1, 2017): 478–86. http://dx.doi.org/10.2166/wpt.2017.053.
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Estimation of total impervious area (TIA) is a pre-requisite for ecohydrological research to allow for a direct prediction on stream ecosystem health within catchments. This paper presents an alternative to using multi-spectral imagery for estimating TIA at a catchment scale, by using high-resolution colour aerial photography. The method was applied to a number of catchments in South East Queensland, Australia, some of which were gauged and some of which were part of an Ecosystem Health Monitoring Program (EHMP). The results from this method were compared to TIA estimates, for some of the same catchments, that were derived through three other techniques, i.e. manual digitization of geo-referenced aerial photos, Brisbane City Council data derived from image analysis using Landsat TM imagery and rainfall runoff depth relationship. The high-resolution colour aerial photography method compared favourably to the other techniques with standard deviations of TIA (%) ranging between 0.8% and 8%. The major constraints were shading effects, particularly on roads and grassed areas, and from the similarity in colours between some surface types, some of which can be reduced by appropriate selection of signature colours and multiple iterations of a supervised classification. It was concluded that while infra-red spectral wave bands could help considerably, the high-resolution colour photography could be applied with confidence to derive catchment-scale TIA estimates.
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Meyer, Lorenz Hans, Marco Heurich, Burkhard Beudert, Joseph Premier, and Dirk Pflugmacher. "Comparison of Landsat-8 and Sentinel-2 Data for Estimation of Leaf Area Index in Temperate Forests." Remote Sensing 11, no. 10 (May 15, 2019): 1160. http://dx.doi.org/10.3390/rs11101160.
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With the launch of the Sentinel-2 satellites, a European capacity has been created to ensure continuity of Landsat and SPOT observations. In contrast to previous sensors, Sentinel-2′s multispectral imager (MSI) incorporates three additional spectral bands in the red-edge (RE) region, which are expected to improve the mapping of vegetation traits. The objective of this study was to compare Sentinel-2 MSI and Landsat-8 OLI data for the estimation of leaf area index (LAI) in temperate, deciduous broadleaf forests. We used hemispherical photography to estimate effective LAI at 36 field plots. We then built and compared simple and multiple linear regression models between field-based LAI and spectral bands and vegetation indices derived from Landsat-8 and Sentinel-2, respectively. Our main findings are that Sentinel-2 predicts LAI with comparable accuracy to Landsat-8. The best Landsat-8 models predicted LAI with a root-mean-square error (RMSE) of 0.877, and the best Sentinel-2 model achieved an RMSE of 0.879. In addition, Sentinel-2′s RE bands and RE-based indices did not improve LAI prediction. Thirdly, LAI models showed a high sensitivity to understory vegetation when tree cover was sparse. According to our findings, Sentinel-2 is capable of delivering data continuity at high temporal resolution.
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Tsutomu, Kadota, and Davaa Gombo. "Recent glacier variations in Mongolia." Annals of Glaciology 46 (2007): 185–88. http://dx.doi.org/10.3189/172756407782871675.
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AbstractGlacier monitoring enables us to detect influences of global warming in high mountain regions. To initiate the establishment of a glacier-monitoring network in northern Eurasia, we studied recent glacier variations in Mongolia using topographical maps, aerial photographs and satellite images (Corona and Landsat). Glaciers in Mongolia exist in the Altai mountains which span approximately 1400 km within Russia, China and Mongolia. Four regions were selected to form the study area: Tavan Bogd region, Turgen massif, Kharkhiraa massif and Tsambagarav massif. During the period from the 1940s to 2000 or from 1968 to 2000, the glaciers in these regions lost 10.2%, 19.3%, 28.0% and 28.8% of their area respectively. The glaciers in the Tavan Bogd, Kharkhiraa and Turgen regions were found to have been almost stationary since 1987/88, while those in Tsambagarav massif showed no significant change in area since 1963. Shrinkage of the glaciers occurred between 1945/68 and 1987/88 in the former regions and between 1948 and 1963 in the latter. Mongolian glaciers seem to behave differently from other glaciers which have been experiencing steady shrinkage recently.
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Moravec, David, Jan Komárek, Serafín López-Cuervo Medina, and Iñigo Molina. "Effect of Atmospheric Corrections on NDVI: Intercomparability of Landsat 8, Sentinel-2, and UAV Sensors." Remote Sensing 13, no. 18 (September 7, 2021): 3550. http://dx.doi.org/10.3390/rs13183550.
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Sentinel-2 and Landsat 8 satellites constitute an unprecedented source of freely accessible satellite imagery. To produce precise outputs from the satellite data, however, proper use of atmospheric correction methods is crucial. In this work, we tested the performance of six different atmospheric correction methods (QUAC, FLAASH, DOS, ACOLITE, 6S, and Sen2Cor), together with atmospheric correction given by providers, non-corrected image, and images acquired using an unmanned aerial vehicle while working with the normalised difference vegetation index (NDVI) as the most widely used index. We tested their performance across urban, rural, and vegetated land cover types. Our results show a substantial impact from the choice of the atmospheric correction method on the resulting NDVI. Moreover, we demonstrate that proper use of atmospheric correction methods can increase the intercomparability between data from Landsat 8 and Sentinel-2 satellite imagery.
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Williams, R. S. "Glacier Inventories of Iceland: Evaluation and Use of Sources of Data." Annals of Glaciology 8 (1986): 184–91. http://dx.doi.org/10.1017/s0260305500001439.
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All sources of cartographic, aerial photographic, satellite image, and related data, from the 18th century to the present, for the eight geographic groups of Iceland’s glaciers, were evaluated for use in preparing a preliminary inventory of Iceland’s glaciers, based on information requirements of the Temporary Technical Secretariat for World Glacier Inventory. On the basis of an evaluation of all sources of historic and modern data for the Langjökull Group, the 1:50 000 scale U.S. Army Map Service Series C762 maps of Iceland were determined to be the best maps from which to derive information for a preliminary inventory, as long as the limitations of these maps are considered and accommodated. The fluctuations of Langjökull’s principal outlet glaciers on maps and Landsat images were found to be consistent with field observations at the International Hydrological Decade monitoring stations. Accumulation area ratios were calculated from late summer snow lines on 1973 Landsat images of Vatnajökull (0.70), Langjökull (0.78), and Mýrdalsjökull (0.35), Measurements of the area of the now stagnant glacier on Ok showed a rapid reduction in area (68 per cent) between 1910 and 1960, but a decline in rate of wastage since 1960 (73 per cent between 1910 and 1978). From 1910 and 1945 topographic maps, the volume of the glacier on Ok was found to be reduced by 0.62 km3.
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Williams, R. S. "Glacier Inventories of Iceland: Evaluation and Use of Sources of Data." Annals of Glaciology 8 (1986): 184–91. http://dx.doi.org/10.3189/s0260305500001439.
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All sources of cartographic, aerial photographic, satellite image, and related data, from the 18th century to the present, for the eight geographic groups of Iceland’s glaciers, were evaluated for use in preparing a preliminary inventory of Iceland’s glaciers, based on information requirements of the Temporary Technical Secretariat for World Glacier Inventory. On the basis of an evaluation of all sources of historic and modern data for the Langjökull Group, the 1:50 000 scale U.S. Army Map Service Series C762 maps of Iceland were determined to be the best maps from which to derive information for a preliminary inventory, as long as the limitations of these maps are considered and accommodated. The fluctuations of Langjökull’s principal outlet glaciers on maps and Landsat images were found to be consistent with field observations at the International Hydrological Decade monitoring stations. Accumulation area ratios were calculated from late summer snow lines on 1973 Landsat images of Vatnajökull (0.70), Langjökull (0.78), and Mýrdalsjökull (0.35), Measurements of the area of the now stagnant glacier on Ok showed a rapid reduction in area (68 per cent) between 1910 and 1960, but a decline in rate of wastage since 1960 (73 per cent between 1910 and 1978). From 1910 and 1945 topographic maps, the volume of the glacier on Ok was found to be reduced by 0.62 km3.
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Loshkareva, A. R., and N. E. Koroleva. "Large-scale map of key area in forest-tundra zone on Kola Peninsula: methods of mapping and analysis of result." Geobotanical mapping, no. 2013 (2013): 112–24. http://dx.doi.org/10.31111/geobotmap/2013.112.
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Large-scale vegetation mapping of key area of 1400 km2 in forest-tundra zone in the middle flow of Teriberkariver (Kola Peninsula) was conducted on the base of satellite images, topographic maps and field geobotanical investigations. Study of Landsat TM images local spectral characteristics and syntaxonomical analysis of vegetation demonstrated that satellite images with 30 m spatial resolution and 6-bands spectral resolution alone can't be used for automatical large-scale classification of forest-tundra zone vegetation. Map of vegetation in scale 1:50 000 resulted from manual processing of both hypsometry and spectral characteristic, on the base of field work points with description of vegetation. Legend of mapped units contains 2 types for tundra, 5 ones for mountain birch forest and 4 ones for wetlands. Quality and correctness of the map were verified by satellite image of extra high spatial resolution Quick Bird (0,65 m/pixel) and aerial photograph for this territory. The map illustrated that distribution of vegetation is primarily caused by unevenness of relief. Timberline lies at 220-240 m a.s.l., altitudinal distances across mountain birch forest and tundra zones are about 40-60 m, tundra vegetation occurs on moraine hills and bedrocks slopes and summits. Pounikkos flark-and-mounds, tuft-and-fen bog complexes occur from 170 to 240 m.s.l. in depressions and valleys. Proportion of tundra vegetation is about 40%, mountain birch forest – 30%, wetlands – 20%, lakes, rivers and springs take 10% of area investigated.
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Silver, M., M. Törmä, K. Silver, M. Nuñez, and J. Okkonen. "CHALLENGING THE INVISIBILITY OF MOBILE CULTURES REMOTE SENSING, ENVIRONMENT AND ARCHAEOLOGY IN THE NEAR EAST." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W11 (May 5, 2019): 1065–72. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w11-1065-2019.
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<p><strong>Abstract.</strong> Remote sensing has provided a modern wider perspective to approach the earth with its various environments and impact of humans by prospecting previously unknown frontiers of human life. The traces of mobile groups are archaeologically often more difficult to detect than those of the sedentary ones, but new approaches and methods have changed and enhanced the ways to extract archaeological information of hunter-gatherers and pastoral nomads. Remote sensing, for example, provides alternative views from above and better visibility in a larger scale, especially with high resolution solutions, than on the ground to trace sites. Mobile people have become more visible in archaeology, and therefore their importance in the development of human cultures has received more focus and understanding. This paper will focus on the use of remote sensing in the archaeological study of mobile cultures and their environments in the Near East. Various examples of techniques and site types will be discussed, and the suitability of applications will be considered based on the studies by Finnish and Finnish-Swedish projects in the Near East. We will provide examples of applications and emphasize the importance of empirical approaches in studying archaeological evidence by remote sensing. GPS coordinate points have served as the basis of our field survey and mapping. From the image-based data we shall deal with aerial photographs, CORONA satellite photographs, Landsat, SPOT, QuickBird and GeoEye satellite images. From the range-based data we shall discuss X-SAR Shuttle Mission 2000 and ASTER-DEM data, but LiDAR and geophysical devices will only be briefly considered.</p>
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Szantoi, Zoltan, Scot E. Smith, Giovanni Strona, Lian Pin Koh, and Serge A. Wich. "Mapping orangutan habitat and agricultural areas using Landsat OLI imagery augmented with unmanned aircraft system aerial photography." International Journal of Remote Sensing 38, no. 8-10 (January 23, 2017): 2231–45. http://dx.doi.org/10.1080/01431161.2017.1280638.
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Evans, Eleri, Richard Essery, and Richard Lucas. "Changing snow cover and the net mass balance of Storglaciären, northern Sweden." Annals of Glaciology 49 (2008): 199–204. http://dx.doi.org/10.3189/172756408787814933.
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AbstractThe spatial and temporal variability of seasonal snow cover in glacierized catchments has important implications for the net mass balance of alpine glaciers. This study examines the relationship between changing snowpack volume, the resulting winter balance and the net mass balance of Storglaciären, northern Sweden. Using a conceptual model, the net seasonal snow input to the glacier is simulated daily for 16 years from 1990. From this the annual snow accumulation and winter balance are calculated. The model outputs are compared with snowlines delineated from classified aerial photographs, ASTER and Landsat 7 ETM+ satellite imagery, and with measured Storglaciären winter balances. The results of the model indicate variability in the winter balance over the study period, though there is a slightly negative trend overall. The highest winter balances and seasonal snow volumes occurred in the early 1990s and correspond with positive net mass balances. However, the slightly negative trend in winter balance and decreased net seasonal snow volumes suggested by the model, combined with the measured increasing trend in mass lost due to ablation, have resulted in decreasing glacier net mass balances and a corresponding rise in ELA over the study period.
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Ferrigno, J. G., B. K. Lucchitta, K. F. Mullins, A. L. Allison, R. J. Allen, and W. G. Gould. "Velocity measurements and changes in position of Thwaites Glacier/iceberg tongue from aerial photography, Landsat images and NOAA AVHRR data." Annals of Glaciology 17 (1993): 239–44. http://dx.doi.org/10.1017/s0260305500012908.
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The Thwaites Glacier/iceberg tongue complex has been a significant feature of the Antarctic coastline for at least 50 years. In 1986, major changes began to occur in this area. Fast ice melted and several icebergs calved from the base of the iceberg tongue and the terminus of Thwaites Glacier. The iceberg tongue rotated to an east-west orientation and drifted westward. Between 1986 and 1992, a total of 140 km of drift has occurred. Remote digital velocity measurements were made on Thwaites Glacier using sequential Landsat images to try to determine if changes in velocity had occurred in conjunction with the changes in ice position. Measurements on Landsat images from 1972 and 1984 revealed an average annual velocity of 2.62 km a−1 during that time period, and measurements on images from 1984 and 1990 an average annual velocity of 2.84kma−1, an increase of more than 8%. Estimates made on Thwaites Glacier by others using earlier data contained enough uncertainty that it was impossible to determine a velocity profile over a longer period of time. Examination of the morphology of the glacier/iceberg tongue showed no evidence of surge activity.
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Ferrigno, J. G., B. K. Lucchitta, K. F. Mullins, A. L. Allison, R. J. Allen, and W. G. Gould. "Velocity measurements and changes in position of Thwaites Glacier/iceberg tongue from aerial photography, Landsat images and NOAA AVHRR data." Annals of Glaciology 17 (1993): 239–44. http://dx.doi.org/10.3189/s0260305500012908.
Full textAbstract:
The Thwaites Glacier/iceberg tongue complex has been a significant feature of the Antarctic coastline for at least 50 years. In 1986, major changes began to occur in this area. Fast ice melted and several icebergs calved from the base of the iceberg tongue and the terminus of Thwaites Glacier. The iceberg tongue rotated to an east-west orientation and drifted westward. Between 1986 and 1992, a total of 140 km of drift has occurred.Remote digital velocity measurements were made on Thwaites Glacier using sequential Landsat images to try to determine if changes in velocity had occurred in conjunction with the changes in ice position. Measurements on Landsat images from 1972 and 1984 revealed an average annual velocity of 2.62 km a−1 during that time period, and measurements on images from 1984 and 1990 an average annual velocity of 2.84kma−1, an increase of more than 8%. Estimates made on Thwaites Glacier by others using earlier data contained enough uncertainty that it was impossible to determine a velocity profile over a longer period of time. Examination of the morphology of the glacier/iceberg tongue showed no evidence of surge activity.
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Petrova, Teodora. "RESEARCH ON ALGORITHMS FOR FILTRATION OF AERIAL AND RADAR IMAGES." KNOWLEDGE INTERNATIONAL JOURNAL 31, no. 6 (June 5, 2019): 1923–36. http://dx.doi.org/10.35120/kij31061923p.
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In the 1960s a new special science of imagery began to develop – „imagery“, which deals with the study of the general image properties, the goals and tasks of their transformation, the processing and reproduction as well as the recognition of graphic images. Image forming, increasing image quality and the automated processing of aerial images including images captured from satellites, unmanned aircraft, radars equipped with synthesizing equipment and so on, are a subject of a number of researches and developments. The automatic analysis is widely applied in modern monitoring systems as the ones used in overwatch of areas, forests, asserting damage done on crops, reconnaissance and in the fire department services. In this article researches are conducted on the use of different image filtering methods from radar with synthesized aperture and aerial photography. The results indicate that filters can used for image pre-treatment under different scenarios, but the appropriate filter and its parameters need to be carefully selected.
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Erena, M., S. Montesinos, D. Portillo, J. Alvarez, C. Marin, L. Fernandez, J. M. Henarejos, and L. A. Ruiz. "CONFIGURATION AND SPECIFICATIONS OF AN UNMANNED AERIAL VEHICLE FOR PRECISION AGRICULTURE." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B1 (June 6, 2016): 809–16. http://dx.doi.org/10.5194/isprsarchives-xli-b1-809-2016.
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Unmanned Aerial Vehicles (UAVs) with multispectral sensors are increasingly attractive in geosciences for data capture and map updating at high spatial and temporal resolutions. These autonomously-flying systems can be equipped with different sensors, such as a six-band multispectral camera (Tetracam mini-MCA-6), GPS Ublox M8N, and MEMS gyroscopes, and miniaturized sensor systems for navigation, positioning, and mapping purposes. These systems can be used for data collection in precision viticulture. In this study, the efficiency of a light UAV system for data collection, processing, and map updating in small areas is evaluated, generating correlations between classification maps derived from remote sensing and production maps. Based on the comparison of the indices derived from UAVs incorporating infrared sensors with those obtained by satellites (Sentinel 2A and Landsat 8), UAVs show promise for the characterization of vineyard plots with high spatial variability, despite the low vegetative coverage of these crops. Consequently, a procedure for zoning map production based on UAV/UV images could provide important information for farmers.