To see the other types of publications on this topic, follow the link: Geodetic instrument.
Journal articles on the topic 'Geodetic instrument'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Geodetic instrument.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Hamza, Veton, Bojan Stopar, Tomaž Ambrožič, Goran Turk, and Oskar Sterle. "Testing Multi-Frequency Low-Cost GNSS Receivers for Geodetic Monitoring Purposes." Sensors 20, no. 16 (August 5, 2020): 4375. http://dx.doi.org/10.3390/s20164375.
Full textAbstract:
Global Navigation Satellite System (GNSS) technology is widely used for geodetic monitoring purposes. However, in cases where a higher risk of receiver damage is expected, geodetic GNSS receivers may be considered too expensive to be used. As an alternative, low-cost GNSS receivers that are cheap, light, and prove to be of adequate quality over short baselines, are considered. The main goal of this research is to evaluate the positional precision of a multi-frequency low-cost instrument, namely, ZED-F9P with u-blox ANN-MB-00 antenna, and to investigate its potential for displacement detection. We determined the positional precision within static survey, and the displacement detection within dynamic survey. In both cases, two baselines were set, with the same rover point equipped with a low-cost GNSS instrument. The base point of the first baseline was observed with a geodetic GNSS instrument, whereas the second baseline was observed with a low-cost GNSS instrument. The results from static survey for both baselines showed comparable results for horizontal components; the precision was on a level of 2 mm or better. For the height component, the results show a better performance of low-cost instruments. This may be a consequence of unknown antenna calibration parameters for low-cost GNSS antenna, while statistically significant coordinates of rover points were obtained from both baselines. The difference was again more significant in the height component. For the displacement detection, a device was used that imposes controlled movements with sub-millimeter accuracy. Results, obtained on a basis of 30-min sessions, show that low-cost GNSS instruments can detect displacements from 10 mm upwards with a high level of reliability. On the other hand, low-cost instruments performed slightly worse as far as accuracy is concerned.
2
Lösler, Michael, Cornelia Eschelbach, and Stefan Riepl. "A modified approach for automated reference point determination of SLR and VLBI telescopes." tm - Technisches Messen 85, no. 10 (October 25, 2018): 616–26. http://dx.doi.org/10.1515/teme-2018-0053.
Full textAbstract:
AbstractThe International Terrestrial Reference Frame (ITRF) is derived by combining several space geodetic techniques. Basically, a meaningful combination of the geodesic space techniques is impossible without further geometrical information, i. e. local-ties. Local-tie vectors are defined between the geometrical reference points of space geodetic techniques at co-location stations. These local-ties are introduced during the inter-technique combination process, to overcome the weak physical connection between the space geodetic techniques. In particular, the determination of the reference point of radio telescopes or laser telescopes is a challenging task and requires indirect methods. Moreover, the Global Geodetic Observing System (GGOS) strives for an automated and continued reference point determination with sub-millimeter accuracy, because deviations in local-ties bias global results.This investigation presents a modified approach for automated reference point determination. The new approach extends the prior work of Lösler but evades the synchronization between the terrestrial instrument and the telescope. Thus, synchronization errors are omitted and the technical effort is reduced. A proof of concept was carried out at Geodetic Observatory Wettzell in 2018. Using a high-precision, mobile laser-tracker, the reference point of the Satellite Observing System Wettzell (SOS-W) was derived. An extended version of the in-house developed software package HEIMDALL was employed for a mostly automated data collection. To evaluate the estimated reference point, the derived results are compared with the results of two approved models.
3
Dvořáček, Filip. "Precision Tests of Geodetic Centring Equipment." Geoinformatics FCE CTU 15, no. 2 (December 8, 2016): 5–14. http://dx.doi.org/10.14311/gi.15.2.1.
Full textAbstract:
The paper introduces testing procedures of several different geodetic centring devices performed mostly at the laboratory of the Research Institute of Geodesy, Topography and Cartography. Functional construction characteristics of a spherically mounted retroreflector Leica RRR 1.5’’, rotatable carriers Sokkia AP41 and Leica GZR3 and 12 different geodetic tribraches were examined. Further, a centring displacement instrument developed at the Czech Technical University in Prague, Faculty of Civil Engineering, Department of Special Geodesy, is evaluated in both laboratory and field conditions. For all tests, laser tracker Leica AT401 with a 5 μm standard uncertainty of absolute distance measurement, was employed.
4
Ustinova, Nelli, Vello Kala, Tarvo Mill, and Artu Ellmann. "GEODETIC SURVEYING STUDIES FOR CIVIL ENGINEERING STUDENTS AT TALLINN UNIVERSITY OF TECHNOLOGY." Geodesy and Cartography 38, no. 2 (June 29, 2012): 86–91. http://dx.doi.org/10.3846/20296991.2012.692213.
Full textAbstract:
Studies in the Tallinn University of Technology are based on a modular system, where geodetic surveying comprises a self-contained study module in the curricula of all civil engineering specialities. Due to geodetic surveying being taught to all first year students of civil engineering, it serves as a touchstone to test a student's suitability for an engineering specialism. Future civil engineers are taught basic geodetic measurements and how to use optical theodolite, levelling instrument and laser level. The paper gives an overview of geodetic surveying lectures, laboratory classes and field survey camp. Teaching and assessment are based on learning outcomes. Students who have passed the exam are allowed to participate in the summer field survey camp, the aim of which is consolidating the knowledge acquired throughout the year and practising teamwork.
5
Šiaudinytė, Lauryna, Mindaugas Rybokas, and Vytautas Giniotis. "ANALYSIS OF ANGLE MEASUREMENTS AND A NEW APPROACH TO VERTICAL ANGLE CALIBATION / VERTIKALIŲJŲ KAMPŲ KALIBRAVIMO ANALIZĖ IR NAUJI KALIBRAVIMOBŪDAI / AНAЛИЗ УГЛOВЫХ ИЗМЕРЕНИЙ И НОВЫE МEТOДЫ КАЛИБРИРOВАНИЯ." Geodesy and Cartography 37, no. 4 (January 11, 2012): 149–53. http://dx.doi.org/10.3846/13921541.2011.645333.
Full textAbstract:
Testing and calibrating geodetic instruments is an important metrological procedure for precise instrumentation used in industry and geodesy. Electronic geodetic measuring instruments consist, among other elements, of circular scales and angular encoders for angle determination in two perpendicular horizontal and vertical planes. The accuracy of the instrument mostly depends on the accuracy of angle standards used for angle calibration in the horizontal plane. Although many methods are developed for angle calibration, the majority of those are not available for calibrating angles in the vertical plane. The method described in the International Standards of vertical angle calibration validates field testing geodetic instruments by taking precise angle readings between the calibrated points placed at long distance and height. Difficulties in creating such calibration basis and inconveniencies in proceeding with this field at long distances may appear. Also, the traceability of length and angle measurements is not ensured. The new method of calibrating the angles in the vertical plane for geodetic instruments was developed. The article describes the principle of indoor testing and the calibration of the vertical angle measuring system. Santrauka Daugelyje optinių elektroninių matavimo prietaisų yra įmontuotos apskritiminės skalės, skirtos kampinei padėčiai dviejose statmenose plokštumose – horizontaliojoje bei vertikaliojoje nustatyti. Prietaiso tikslumas daugiausia priklauso nuo sių skalių tikslumo. Rastrinių skalių metrologija yra gana specifinė sritis, būtina tam tikra metodika ir kalibravimo įranga. Trumpai apžvelgus pateikiami kai kurie būdai ir priemonės, taikytini kampų metrologijai, ypač vertikaliam plokščiajam kampui kalibruoti. Резюме Многие оптико-электронные измерительные инструменты состоят из круговых шкал для определения углов в двух перпендикулярных плоскостях – горизонтальной и вертикальной. Точность инструмента в основном зависит от точности этих угломерных шкал. Метрология угловых растровыx шкал довольно специфична и требует специфических мeтодов и приспособлений для калибрирования. В статье приводится обзор и некоторые простые способы и приспособления, которые можно использовать в метрологии углов, в частности, в калибрировании вертикального плоского угла.
6
Shcherbakov, Vladimir, Ivan Shcherbakov, and Vladimir Astrahancev. "DEVICE OF THE ROAD MASTER TO CONTROL GEOMETRY RAIL TRACK." Interexpo GEO-Siberia 1, no. 1 (2019): 71–76. http://dx.doi.org/10.33764/2618-981x-2019-1-1-71-76.
Full textAbstract:
This article presents the development of an automated tool and method for ensuring the con-trol of the geometry of a rail track, which includes the functions of the traditional track template of the MCC type, as well as new functions not previously used in the instruments of the road master. The functionality of the instrument for instrumental inspection of railways is given, which is one of the tasks of equalizing the capabilities of mobile high-performance diagnostic tools for rail gauge and the superstructure of the track with measuring instruments of a road craftsman who is responsi-ble for the condition of the track. The technical characteristics of the road master device (PDM) are also given, and the results of the preliminary tests performed are assessed, which make it possible to automate the geodetic work most frequently performed by road foremen.
7
Beran, Tomas, Lee Danisch, Adam Chrzanowski, and Maciej Bazanowski. "Measurement of Deformations by MEMS Arrays, Verified at Sub-millimetre Level Using Robotic Total Stations." Geoinformatics FCE CTU 12 (June 3, 2014): 34–40. http://dx.doi.org/10.14311/gi.12.6.
Full textAbstract:
Measurement of sub-millimetre-level deformations of structures in the presence of ambient temperature changes can be challenging. This paper describes the measurement of a structure moving due to temperature changes, using two ShapeAccelArray (SAA) instruments, and verified by a geodetic monitoring system. SAA is a geotechnical instrument often used for monitoring of displacements in soil. SAA uses micro-electromechanical system (MEMS) sensors to measure tilt in the gravity field. The geodetic monitoring system, which uses ALERT software, senses the displacements of targets relative to control points, using a robotic total station (RTS). The test setup consists of a central four-metre free-standing steel tube with other steel tubes welded to most of its length. The central tube is anchored in a concrete foundation. This composite “pole” is equipped with two SAAs as well as three geodetic prisms mounted on the top, in the middle, and in the foundation. The geodetic system uses multiple control targets mounted in concrete foundations of nearby buildings, and at the base of the pole. Long-term observations using two SAAs indicate that the pole is subject to deformations due to cyclical ambient temperature variations causing the pole to move by a few millimetres each day. In a multiple-day experiment, it was possible to track this movement using SAA as well as the RTS system. This paper presents data comparing the measurements of the two instruments and provides a good example of the detection of two-dimensional movements of seemingly rigid objects due to temperature changes.
8
Paar, Rinaldo, Miodrag Roić, Ante Marendić, and Stjepan Miletić. "Technological Development and Application of Photo and Video Theodolites." Applied Sciences 11, no. 9 (April 25, 2021): 3893. http://dx.doi.org/10.3390/app11093893.
Full textAbstract:
Theodolites are fundamental geodetic measuring instruments for all practical geodetic tasks, as well as for experimental geodetic scientific purposes. Their development has a long history. Photo and video theodolites represent the advanced development of classic theodolites. Development started in 19th century, but only in the last 15 years has commercial application been achieved in the geodetic profession. The latest development, called image-assisted total stations (IATS), is a theodolite which consists of a classic robotic total station (RTS) with integrated image sensors. It was introduced in the early 2000s. With the development of theodolites, their application became much wider; today, they can be used for structural and geo-monitoring, i.e., for the determination of static and dynamic displacements and deformations of civil engineering structures such as bridges, dams, wind turbines, and high buildings, as well as natural structures, such as mountain slopes. They can be implemented in geodetic monitoring systems, which are an integral part of engineering structural diagnosis, and they provide essential information about the current condition of the structure. This paper describes the technological development of photo and video theodolites divided into phases according to the main innovations in their development. The application of modern video theodolites (i.e., IATS) is presented through several experimental studies that were performed. The procedure of conducting measurements with this kind of instrument, as well as the analysis of acquired data and achieved results, is elaborated. Lastly, the authors conclude, according to the achieved results, that IATS can today be used for determination of quasi-static and dynamic displacements with small and high amplitudes.
9
GORB, A., and I. TREVOHO. "Innovative digital technologies in geodesy and geoinformatics at first online INTERGEO 2020." Modern achievements of geodesic science and industry 41, no. I (April 1, 2021): 16–22. http://dx.doi.org/10.33841/1819-1339-1-41-16-22.
Full textAbstract:
The analysis of the main news of the INTERGEO 2020 exhibition in Berlin in the field of geodetic instrument engineering is carried out, the characteristics of new systems and professional comment are given
10
Golubkova, O. K., and A. I. Spiridonov. "Anniversary of the first national standards for geodetic instruments." Geodesy and Cartography 946, no. 4 (May 20, 2019): 20–25. http://dx.doi.org/10.22389/0016-7126-2019-946-4-20-25.
Full textAbstract:
State standards on the types, basic parameters of levels and theodolites as well as technical requirements were developed in CNIIGAiK in 1962–1963. The authors indicate the experience of developing the first State standards for geodetic instrument making, the difficulties encountered in developers. In this article the main stages of preparation of State standards, including action algorithm from technical specifications to submissions for the approval of the public service are marked step-by-step. The types of levels and theodolites, and the basic technical characteristics for each type are described. During 55 years the positive impact in the areas of production and application of standardized levels and theodolites, inter alia, streamlining the issuance of standard sizes of devices, increased production and improved their quality and technical level was revealed.
11
Hamza, Veton, Bojan Stopar, Tomaž Ambrožič, and Oskar Sterle. "Performance Evaluation of Low-Cost Multi-Frequency GNSS Receivers and Antennas for Displacement Detection." Applied Sciences 11, no. 14 (July 20, 2021): 6666. http://dx.doi.org/10.3390/app11146666.
Full textAbstract:
Low-cost Global Navigation Satellite System (GNSS) receivers are currently used in various engineering applications. These low-cost devices are regarded as suitable sensors for applications in areas with a high risk of instrument damage. The main objectives of this research were to identify the size of displacements that can be detected in relative and absolute positioning modes by low-cost GNSS instruments and to compare the results of selected antennas. Additionally, geodetic and low-cost GNSS instruments were compared in the level of observations. For this study, low-cost SimpleRTK2B V1 boards, which house ZED-F9P GNSS chips, and three low-cost antennas, namely, Survey, Tallysman TW3882, and Survey Calibrated, were selected. While antenna calibration parameters are known for the last antenna, this is not the case for the first two. For testing purposes, a geodetic network consisting of four points was established; horizontal and vertical movements were imposed by a special mechanism with high accuracy. In relative positioning mode, the results indicate that the Survey Calibrated antenna can detect horizontal and vertical displacements with sizes of 4 mm, and 6 mm, respectively. In the detection of horizontal displacements, the performance of the Survey antenna was not as good as that of Tallysman, and the sizes of detected displacements were 6 mm and 4 mm for the first, and second antennas, respectively. Vertical displacements of 9 mm were detected using both Survey and Tallysman antennas. In absolute positioning mode, Survey Calibrated also had better performance than the Tallysman antenna, and spatial displacements of 20 mm or greater were detected by low-cost GNSS instruments. The observations made with low-cost and geodetic GNSS instruments were compared, and the latter showed better performance. However, the differences in cycle slips and the noise of phase observations were inferior. Considering their cost and proven performance, it can be concluded that such sensors can be considered for setting up a highly accurate but low-cost geodetic monitoring system.
12
Pettersen, Bjørn Ragnvald. "THE NORWEGIAN PART OF THE STRUVE GEODETIC ARC – AN ORIGINAL INSTRUMENT REDISCOVERED." Survey Review 39, no. 306 (October 2007): 294–307. http://dx.doi.org/10.1179/175227007x197200.
Full text
13
Woźniak, Marek, and Waldemar Odziemczyk. "Investigation of Stability of Precise Geodetic Instruments Used in Deformation Monitoring." Reports on Geodesy and Geoinformatics 104, no. 1 (December 20, 2017): 79–90. http://dx.doi.org/10.1515/rgg-2017-0017.
Full textAbstract:
Abstract Monitoring systems using automated electronic total stations are an important element of safety control of many engineering objects. In order to ensure the appropriate credibility of acquired data, it is necessary that instruments (total stations in most of the cases) used for measurements meet requirements of measurement accuracy, as well as the stability of instrument axis system geometry. With regards to the above, it is expedient to conduct quality control of data acquired using electronic total stations in the context of performed measurement procedures. This paper presents results of research conducted at the Faculty of Geodesy and Cartography at Warsaw University of Technology investigating the stability of “basic” error values (collimation, zero location for V circle, inclination), for two types of automatic total stations: TDA 5005 and TCRP 1201+. Research provided also information concerning the influence of temperature changes upon the stability of investigated instrument’s optical parameters. Results are presented in graphical analytic technique. Final conclusions propose methods, which allow avoiding negative results of measuring tool-set geometry changes during conducting precise deformation monitoring measurements.
14
Murzintsev, Petr P., Alexey V. Novikov, and Alexander S. Repin. "STUDY OF THE LED REMOVABLE NOZZLE ON THE REFLECTOR OF AN ELECTRON TOTAL STATION." Interexpo GEO-Siberia 1, no. 1 (July 8, 2020): 64–73. http://dx.doi.org/10.33764/2618-981x-2020-1-1-64-73.
Full textAbstract:
The article presents the results of a study of a removable LED nozzle on the reflector of an electronic total station. A description of the LED removable nozzle on the reflector of the electronic total station is made. The results of measurements of the runtime of pointing the device at the reflector at night, at various distances and in bad weather conditions (snowfall) are presented. A comparison between the results of studies with different backlight modes of the total station reflector is made. Models of reflectors with pulsed illumination manufactured by various instrument-making enterprises and their cost are given. Based on the results of the studies and analysis, conclusions on the use of a removable LED nozzle for performing geodetic measurements in the production of engineering and geodetic surveys and other types of geodetic works are drawn. The advantages and disadvantages of the LED removable nozzle are given.
15
Kamiński, Waldemar. "New Method for Determination of Adjustment Corrections for Crane Rail Axes." Reports on Geodesy and Geoinformatics 94, no. 1 (October 1, 2013): 47–55. http://dx.doi.org/10.2478/rgg-2013-0006.
Full textAbstract:
Abstract Electronic tacheometers are currently a standard instrument used in geodetic work, including also geodetic engineering measurements. One of the many applications of tacheometers in engineering geodesy are 3D control measurements of crane rail axes. This paper proposes a new method of computing adjustment corrections for crane rail axes based on 3D polar measurements performed with an electronic tacheometer. The intermediary method with conditions on parameters was used in the solution of the problem. The theoretical discussion was complemented with an example application on simulated results of observations. The obtained results confirmed the theoretical assumptions and encourage the verification of the presented proposal on practical examples.
16
Sztubecki, Jacek, Adam Bujarkiewicz, and Małgorzata Sztubecka. "Measuring Displacements in Engineering Structures by Means of a Coordinate Laser Station." Civil And Environmental Engineering Reports 23, no. 4 (December 1, 2016): 145–60. http://dx.doi.org/10.1515/ceer-2016-0059.
Full textAbstract:
Abstract The application of geodetic methods to examine structures consists in the determination of their displacements relative to an established geodetic reference datum or in the definition of the geometry of their individual components. Such examinations form a picture of changes happening between specific points in time. Modern measurement technologies used in geodetic engineering enable undertaking more and more challenging measurements with increasing accuracy. The purpose of this article is to present a measurement technique involving a Leica TDRA 6000 total station to measure displacements in engineering structures. The station features a direct drive technology to achieve an accuracy of 0.25 mm in 3-dimensional measurements. Supported by appropriate software, the unit makes a perfect instrument for the monitoring of civil engineering structures. The article presents the results of measurement of static and dynamic displacements in a few engineering structures. The measurements were carried out both in laboratory conditions and on actual, operated civil engineering structures.
17
Chen, Feng, Liang Yao Gu, Yue Yang, and Xiang Hua Wu. "Reconstruction Method of Existing Speed Rail Based on Precision Measurement." Applied Mechanics and Materials 256-259 (December 2012): 1761–64. http://dx.doi.org/10.4028/www.scientific.net/amm.256-259.1761.
Full textAbstract:
Absolute measuring principle of the high-speed rail was introduced to the measurement of existing speed rail. The line parameter reconstruction and long-wave smooth management is implemented. CPIII control points are laid along existing speed rail. Using the track fine-adjustment instrument, the center geodetic coordinates of midline of track were measured precisely. By least squares fitting method, parameters of straight line between curves was calculated. Plane curve were reconstructed based on measured geodetic coordinates of the continuous rail. The optimization results were used for the theoretical basis, and smoothness of 30 meters chord and 300 meters chord of rail were analyzed, and adjustments of plane curve were calculated to meet the long-wave smooth of rail.
18
García-Balboa, José, Antonio Ruiz-Armenteros, José Rodríguez-Avi, Juan Reinoso-Gordo, and Juan Robledillo-Román. "A Field Procedure for the Assessment of the Centring Uncertainty of Geodetic and Surveying Instruments." Sensors 18, no. 10 (September 20, 2018): 3187. http://dx.doi.org/10.3390/s18103187.
Full textAbstract:
The uncertainty evaluation of survey measurements is a daily and essential task in any surveying work. The result of a measurement is, in fact, only complete when accompanied by a statement of its uncertainty. Miscentring, or centring error, is one of the sources of uncertainty in every basic survey measurement which may have a great effect on horizontal angle measurement for short distances. In the literature, different terms and values are considered to refer to this source of uncertainty. Standard ISO 17123 provides different procedures for assessing the measurement uncertainty of geodetic and surveying instruments, with the aim of checking their suitability for the intending and immediate task in field conditions. ISO 17123 is aware of the importance of uncertainty in the instrument centring, but it does not propose any standardised procedure for its assessment. In this study, we propose such a procedure following a Type A evaluation (through the statistical analysis of series of observations), avoiding using values from Type B evaluations (from manufacturer’s specifications, handbooks, personal experiences, etc.) that could be unsuitable for the conditions of the task. Uncertainty can be individualised for a particular instrument (which includes the plummet type), ground mark, operator, and other factors on which the results could be dependent. The testing methodology includes a configuration of the test field, measurements, and calculation, following the structure of each part of the standard ISO 17123. An experimental application is included with two different total stations, which also includes a statistical analysis of the results.
19
Serdakov, L. E., P. P. Murzincev, D. B. Burenkov, and А. V. Polianskiy. "On choosing the laser tracker stations location for installation of technological equipment." Geodesy and Cartography 953, no. 11 (December 20, 2019): 22–25. http://dx.doi.org/10.22389/0016-7126-2019-953-11-22-25.
Full textAbstract:
A review article on the alignment of technological equipment located on a closed ring path (for example cyclic accelerators). Such geodesic works are very difficult, since the tolerance for alignment in the radial and altitude directions is 0,05 mm. The main survey instrument in such works is a laser tracker. The positions of the laser tracker stations were studied during equipment alignment, taking into account the effect of errors in the transverse directions. The values of the mean square errors for the distances and angles of the API trackers are used. Calculations are made for distances from 0,5 to 10 meters usual for production of precision measurements. The cases of installation of a laser tracker outside and inside the project radius are considered. The results of error calculations when changing the vertical angle of the laser tracker are also presented. The obtained results enable determining the 3D zones for the alignment process equipment, which will improve the efficiency of geodetic works.
20
Fomalont, Edward B. "The VLB array: a new geophysical tool." Symposium - International Astronomical Union 128 (1988): 445–51. http://dx.doi.org/10.1017/s0074180900119874.
Full textAbstract:
The National Radio Astronomy Observatory is constructing a Very Long Baseline Array (VLBA) consisting of ten antennas across the USA, between Hawaii and the Virgin Islands. The array will be a dedicated instrument for producing milliarcsecond images of radio sources. However, exciting geophysical applications of the array are obvious and, furthermore, detailed geodetic, astrometric and environmental parameters are necessary for the VLBA to achieve its full sensitivity, resolution and positional capabilities.
21
Garattini, M., S. Dell’Agnello, D. Currie, G. O. Delle Monache, M. Tibuzzi, G. Patrizi, S. Berardi, et al. "MOONLIGHT: A NEW LUNAR LASER RANGING RETROREFLECTOR INSTRUMENT." Acta Polytechnica 53, A (December 17, 2013): 821–24. http://dx.doi.org/10.14311/ap.2013.53.0821.
Full textAbstract:
Since 1969 Lunar Laser Ranging (LLR) to the Apollo Cube Corner Reflector (CCR) arrays has supplied several significant tests of gravity: Geodetic Precession, the Strong and Weak Equivalence Principle (SEP, WEP), the Parametrized Post Newtonian (PPN) parameter , the time change of the Gravitational constant (G), 1/r<sup>2</sup> deviations and new gravitational theories beyond General Relativity (GR), like the unified braneworld theory (G. Dvali et al., 2003). Now a new generation of LLR can do better using evolved laser retroreflectors, developed from tight collaboration between my institution, INFN–LNF (Istituto Nazionale di Fisica Nucleare – Laboratori Nazionali di Frascati), and Douglas Currie (University of Maryland, USA), one of the fathers of LLR. The new lunar CCR is developing and characterizing at the “Satellite/Lunar laser ranging Characterization Facility” (SCF), in Frascati, performing our new industry standard space test procedure, the “SCF-Test”; this work contains the experimental results of the SCF-Test applied to the new lunar CCR, and all the new payload developments, including the future SCF tests. The International Lunar Network (ILN) research project considers our new retroreflector as one of the possible “Core Instruments”
22
Hyklová, Petra, and Martin Šolc. "František Nušl, Vice-President of the IAU 1928–1935, and inventor of the circumzenithal telescope." Proceedings of the International Astronomical Union 13, S349 (December 2018): 197–202. http://dx.doi.org/10.1017/s1743921319000310.
Full textAbstract:
AbstractThe Czech astronomer František Nušl (1867–1951) was professor of mathematics, practical astronomy and geometrical optics at Prague Charles University. His scientific contribution to astronomy consisted mainly of inventing and constructing of new astronomical and geodetical instruments. Together with his friend Josef Jan Frič, founder of the Ondřejov Observatory, he developed and improved the circumzenithal telescope (1899–1903–1906–1922–1932), a portable instrument with a mercury horizon for determining the geodetic position using the Gauss method of equal altitudes. This instrument won the gold medal at the Exposition Internationale des Arts et Techniques dans la Vie Moderne in Paris in 1937. Nušl, independently of Ernst Öpik, invented the wobbling mirror for determining the velocity of meteors by visual observation, and constructed an unique guiding system for the Ondrejov astrograph etc. The organizational activities of Frantisek Nušl were considerably rich, too: He was one of the founders of the Czech Astronomical Society in 1917, in the years 1922–1948 he served as its president. From 1918 until his retirement in 1937 he was the director of the Ondrejov Observatory, 40 km south of capital city of Prague, lectured astronomy at the Prague university and held many popular lectures including regular courses in radio broadcasting. František Nušl was member of several commisions of international scientific unions; he organized the 3rd General Assembly of IUGG (International Union of Geodesy and Geophysics) in Prague 1927, and in IAU (International Astronomical Union) he was elected as Vice-President in the years 1928–1935. One can conclude that he was the main person who formed the Czech astronomy in the interwar period.
23
Butt, Jemil, Andreas Wieser, Zan Gojcic, and Caifa Zhou. "Machine learning and geodesy: A survey." Journal of Applied Geodesy 15, no. 2 (February 20, 2021): 117–33. http://dx.doi.org/10.1515/jag-2020-0043.
Full textAbstract:
Abstract The goal of classical geodetic data analysis is often to estimate distributional parameters like expected values and variances based on measurements that are subject to uncertainty due to unpredictable environmental effects and instrument specific noise. Its traditional roots and focus on analytical solutions at times require strong prior assumptions regarding problem specification and underlying probability distributions that preclude successful application in practical cases for which the goal is not regression in presence of Gaussian noise. Machine learning methods are more flexible with respect to assumed regularity of the input and the form of the desired outputs and allow for nonparametric stochastic models at the cost of substituting easily analyzable closed form solutions by numerical schemes. This article aims at examining common grounds of geodetic data analysis and machine learning and showcases applications of algorithms for supervised and unsupervised learning to tasks concerned with optimal estimation, signal separation, danger assessment and design of measurement strategies that occur frequently and naturally in geodesy.
24
Gelman, R. N., and A. V. Nikitin. "Radius measurement of a revolution surface: photogrammetric and geodetic variants." Geodesy and Cartography 927, no. 9 (October 20, 2017): 30–36. http://dx.doi.org/10.22389/0016-7126-2017-927-9-30-36.
Full textAbstract:
A description of methods for measuring the radius of curvature of any surface of revolution without the use of special devices and direct contact with the object is given. The method the minimum number of linear and angular measurements at a single point of tool is based on. The height of the cross section for which the radius of curvature is determined can be different with respect to the standpoint. The method in the photogrammetric version, when the main measurements taking from a photograph and a purely geodetic using traditional instrument, can be used. At azimuth geodetic option disappear the process of measuring the image and the issues associated with camera calibration, but requires bulky and expensive equipment as well as additional measurement of angles. Photogrammetric method is more suitable in urban environments due to its simplicity and speed. The justification of the tolerances during installation of the camera is given; a simplified method for its calibration is given; as well as an example of using the photogrammetric method for measuring a real object.
25
Lukac, Carl F., Paul J. Wheeler, Richard E. Keating, and Randolph T. Clarke. "Timing and Data Acquisition System for a Field Astrolabe." Symposium - International Astronomical Union 109 (1986): 397–406. http://dx.doi.org/10.1017/s0074180900076828.
Full textAbstract:
The Danjon Astrolabe at the Naval Observatory has been traditionally used to determine Universal Time and improve the systematic accuracy of star positions. During the past year, it has been used to determine latitude and longitude at remotely scattered sites for geodetic purposes. Operating this instrument away from the Observatory necessitated a mobile support and timing system rugged enough to operate dependably in ever changing, and sometimes harsh, environmental conditions.This paper describes the performance of the astrolabe timing and data acquisition system, gives engineering design considerations, and describes the equipment and instrumentation.
26
Kaasalainen, S., H. Kaartinen, A. Kukko, K. Anttila, and A. Krooks. "Brief communication "Application of mobile laser scanning in snow cover profiling"." Cryosphere 5, no. 1 (March 1, 2011): 135–38. http://dx.doi.org/10.5194/tc-5-135-2011.
Full textAbstract:
Abstract. We present a snowmobile-based mobile mapping system and its first application to snow cover roughness and change detection measurement. The ROAMER mobile mapping system, constructed at the Finnish Geodetic Institute, consists of the positioning and navigating systems, a terrestrial laser scanner, and the carrying platform (a snowmobile sledge in this application). We demonstrate the applicability of the instrument to snow cover roughness profiling and change detection by presenting preliminary results from a mobile laser scanning (MLS) campaign. The results show the potential of MLS for fast and efficient snow profiling from large areas in a millimetre scale.
27
Kaasalainen, S., H. Kaartinen, A. Kukko, K. Anttila, and A. Krooks. "Brief communication "Application of mobile laser scanning in snow cover profiling"." Cryosphere Discussions 4, no. 4 (November 30, 2010): 2513–22. http://dx.doi.org/10.5194/tcd-4-2513-2010.
Full textAbstract:
Abstract. We present a snowmobile based mobile mapping system and its first application on snow cover roughness and change detection measurement. The ROAMER mobile mapping system, constructed at the Finnish Geodetic Institute, consists of the positioning and navigating systems, a terrestrial laser scanner, and the carrying platform (a snowmobile sledge in this application). We demonstrate the applicability of the instrument in snow cover roughness profiling and change detection by presenting preliminary results from a mobile laser scanning (MLS) campaign. The results show the potential of MLS for fast and efficient snow profiling from large areas in a millimetre scale.
28
Frank, William B., and Emily E. Brodsky. "Daily measurement of slow slip from low-frequency earthquakes is consistent with ordinary earthquake scaling." Science Advances 5, no. 10 (October 2019): eaaw9386. http://dx.doi.org/10.1126/sciadv.aaw9386.
Full textAbstract:
Slow slip transients on faults can last from seconds to months and stitch together the earthquake cycle. However, no single geophysical instrument is able to observe the full range of slow slip because of bandwidth limitations. Here, we connect seismic and geodetic data from the Mexican subduction zone to explore an instrumental blind spot. We establish a calibration of the daily median amplitude of the seismically recorded low-frequency earthquakes to the daily geodetically recorded moment rate of previously established slow slip events. This calibration allows us to use the precise evolution of low-frequency earthquake activity to quantitatively measure the moment of smaller, subdaily slip events that are unresolvable by geodesy alone. The resulting inferred slow slip moments scale with duration and inter-event time like ordinary earthquakes. These new quantifications help connect slow and fast events in a broad spectrum of transient slip and suggest that slow slip events behave much like ordinary earthquakes.
29
Gargula, Tadeusz. "Adjustment of an Integrated Geodetic Network Composed of GNSS Vectors and Classical Terrestrial Linear Pseudo-Observations." Applied Sciences 11, no. 10 (May 11, 2021): 4352. http://dx.doi.org/10.3390/app11104352.
Full textAbstract:
The paper proposes a new method for adjusting classical terrestrial observations (total station) together with satellite (GNSS-Global Navigation Satellite Systems) vectors. All the observations are adjusted in a single common three-dimensional system of reference. The proposed method does not require the observations to be projected onto an ellipsoid or converted between reference systems. The adjustment process follows the transformation of a classical geodetic network (distances and horizontal and vertical angles) into a spatial linear (distance) network. This step facilitates easy integration with GNSS vectors when results are numerically processed. The paper offers detailed formulas for calculating pseudo-observations (spatial distances) from input terrestrial observations (horizontal and vertical angles, horizontal distances, height of instrument and height of target). The next stage was to set observation equations and transform them into a linear form (functional adjustment model of geodetic observations). A method was provided as well for determining the mean errors of the pseudo-observations, necessary to assess the accuracy of the values following the adjustment (point coordinates). The proposed algorithm was verified in practice whereby an integrated network made up of a GNSS vector network and a classical linear-angular network was adjusted.
30
Martini, M., S. Dell’Agnello, D. Currie, G. O. Delle Monache, R. Vittori, S. Berardi, A. Boni, et al. "MOONLIGHT: A NEW LUNAR LASER RANGING RETROREFLECTOR AND THE LUNAR GEODETIC PRECESSION." Acta Polytechnica 53, A (December 17, 2013): 746–49. http://dx.doi.org/10.14311/ap.2013.53.0746.
Full textAbstract:
Since the 1970s Lunar Laser Ranging (LLR) to the Apollo Cube Corner Retroreflector (CCR) arrays (developed by the University of Maryland, UMD) supplied almost all significant tests of General Relativity (Alley et al., 1970; Chang et al., 1971; Bender et al.,1973): possible changes in the gravitational constant, gravitational self-energy, weak equivalence principle, geodetic precession, inverse-square force-law. The LNF group, in fact, has just completed a new measurement of the lunar geodetic precession with Apollo array, with accuracy of 9 × 10−3, comparable to the best measurement to date. LLR has also provided significant information on the composition and origin of the moon. This is the only Apollo experiment still in operation. In the 1970s Apollo LLR arrays contributed a negligible fraction of the ranging error budget. Since the ranging capabilities of ground stations improved by more than two orders of magnitude, now, because of the lunar librations, Apollo CCR arrays dominate the error budget. With the project MoonLIGHT (Moon Laser Instrumentation for General relativity High-accuracy Tests), in 2006 INFN-LNF joined UMD in the development and test of a new-generation LLR payload made by a single, large CCR (100mm diameter) unaffected by the effect of librations. With MoonLIGHT CCRs the accuracy of the measurement of the lunar geodetic precession can be improved up to a factor 100 compared to Apollo arrays. From a technological point of view, INFN-LNF built and is operating a new experimental apparatus (Satellite/lunar laser ranging Characterization Facility, SCF) and created a new industry-standard test procedure (SCF-Test) to characterize and model the detailed thermal behavior and the optical performance of CCRs in accurately laboratory-simulated space conditions, for industrial and scientific applications. Our key experimental innovation is the concurrent measurement and modeling of the optical Far Field Diffraction Pattern (FFDP) and the temperature distribution of retroreflector payloads under thermal conditions produced with a close-match solar simulator. The apparatus includes infrared cameras for non-invasive thermometry, thermal control and real-time payload movement to simulate satellite orientation on orbit with respect to solar illumination and laser interrogation beams. These capabilities provide: unique pre-launch performance validation of the space segment of LLR/SLR (Satellite Laser Ranging); retroreflector design optimization to maximize ranging efficiency and signal-to-noise conditions in daylight. Results of the SCF-Test of our CCR payload will be presented. Negotiations are underway to propose our payload and SCF-Test services for precision gravity and lunar science measurements with next robotic lunar landing missions. In particular, a scientific collaboration agreement was signed on Jan. 30, 2012, by D. Currie, S. Dell’Agnello and the Japanese PI team of the LLR instrument of the proposed SELENE-2 mission by JAXA (Registered with INFN Protocol n. 0000242-03/Feb/2012). The agreement foresees that, under no exchange of funds, the Japanese single, large, hollow LLR reflector will be SCF-Tested and that MoonLIGHT will be considered as backup instrument.
31
Mrówczyńska, Maria. "EVOLUTIONARY STRATEGY (μ+λ) AS AN INSTRUMENT FOR DETERMINING DEFORMATION PARAMETERS OF STEEL STRUCTURES." Reports on Geodesy and Geoinformatics 95, no. 1 (December 1, 2013): 23–35. http://dx.doi.org/10.2478/rgg-2013-0010.
Full textAbstract:
Abstract The article presents the use of an evolutionary algorithm for determining the shape of the guy rope sag of a steel smokestack. The author excludes the analysis of the operation of the rope, and discusses only the problem of determining parameters of the function of the adaption of the rope sag curve into empirical data, obtained by the geodetic method. The estimation of parameters of the curve and the characteristics of the accuracy of its adaption into experimental data were carried out by means of an evolutionary algorithm with the use of an evolutionary strategy (μ+λ). The correctness of the strategy presented in the paper, as an instrument for searching for a global minimum of a criterion function, has been presented using as an example the minimisation of a certain two dimensional function and the estimation of parameters of an ordinary and orthogonal regression function. Previous theoretical analyses have also been used for determining parameters of the guy rope sag of a steel smokestack, which is measured periodically. In addition approximate values of the pull forces in the guy ropes have been calculated.
32
Spielvogel, Andrew R., and Louis L. Whitcomb. "Adaptive bias and attitude observer on the special orthogonal group for true-north gyrocompass systems: Theory and preliminary results." International Journal of Robotics Research 39, no. 2-3 (November 5, 2019): 321–38. http://dx.doi.org/10.1177/0278364919881689.
Full textAbstract:
This article reports an adaptive sensor bias observer and attitude observer operating directly on [Formula: see text] for true-north gyrocompass systems that utilize six-degree-of-freedom inertial measurement units (IMUs) with three-axis accelerometers and three-axis angular rate gyroscopes (without magnetometers). Most present-day low-cost robotic vehicles employ attitude estimation systems that employ microelectromechanical system (MEMS) magnetometers, angular rate gyros, and accelerometers to estimate magnetic attitude (roll, pitch, and magnetic heading) with limited heading accuracy. Present-day MEMS gyros are not sensitive enough to dynamically detect the Earth’s rotation, and thus cannot be used to estimate true-north geodetic heading. Relying on magnetic compasses can be problematic for vehicles that operate in environments with magnetic anomalies and those requiring high-accuracy navigation as the limited accuracy ([Formula: see text] error) of magnetic compasses is typically the largest error source in underwater vehicle navigation systems. Moreover, magnetic compasses need to undergo time-consuming recalibration for hard-iron and soft-iron errors every time a vehicle is reconfigured with a new instrument or other payload, as very frequently occurs on oceanographic marine vehicles. In contrast, the gyrocompass system reported herein utilizes fiber optic gyroscope (FOG) IMU angular rate gyro and MEMS accelerometer measurements (without magnetometers) to dynamically estimate the instrument’s time-varying true-north attitude (roll, pitch, and geodetic heading) in real-time while the instrument is subject to a priori unknown rotations. This gyrocompass system is immune to magnetic anomalies and does not require recalibration every time a new payload is added to or removed from the vehicle. Stability proofs for the reported bias and attitude observers, preliminary simulations, and a full-scale vehicle trial are reported that suggest the viability of the true-north gyrocompass system to provide dynamic real-time true-north heading, pitch, and roll utilizing a comparatively low-cost FOG IMU.
33
Manoussakis, Gerassimos, Romylos Korakitis, and Paraskevas Milas. "Gravimetric estimation of the Eötvös matrix components." Contributions to Geophysics and Geodesy 47, no. 1 (March 28, 2017): 53–68. http://dx.doi.org/10.1515/congeo-2017-0004.
Full textAbstract:
Abstract The components of the Eötvös matrix are useful for various geodetic applications, such as interpolation of the elements of the deflection of the vertical, determination of gravity anomalies and determination of geoid heights. A torsion balance instrument is customarily used to determine the Eötvös components. In this work, we show that it is possible to estimate the Eötvös components at a point on the Earth’s physical surface using gravity measurements at three nearby points, comprising a very small network. In the first part, we present the method in detail, while in the second part we demonstrate a numerical example. We conclude that this method is able to estimate the components of the Eötvös matrix with satisfactory accuracy.
34
Holst, Christoph, Tomislav Medić, and Heiner Kuhlmann. "Dealing with systematic laser scanner errors due to misalignment at area-based deformation analyses." Journal of Applied Geodesy 12, no. 2 (April 25, 2018): 169–85. http://dx.doi.org/10.1515/jag-2017-0044.
Full textAbstract:
Abstract The ability to acquire rapid, dense and high quality 3D data has made terrestrial laser scanners (TLS) a desirable instrument for tasks demanding a high geometrical accuracy, such as geodetic deformation analyses. However, TLS measurements are influenced by systematic errors due to internal misalignments of the instrument. The resulting errors in the point cloud might exceed the magnitude of random errors. Hence, it is important to assure that the deformation analysis is not biased by these influences. In this study, we propose and evaluate several strategies for reducing the effect of TLS misalignments on deformation analyses. The strategies are based on the bundled in-situ self-calibration and on the exploitation of two-face measurements. The strategies are verified analyzing the deformation of the Onsala Space Observatory’s radio telescope’s main reflector. It is demonstrated that either two-face measurements as well as the in-situ calibration of the laser scanner in a bundle adjustment improve the results of deformation analysis. The best solution is gained by a combination of both strategies.
35
Gonsette, Alexandre, Jean Rasson, and François Humbled. "In situ vector calibration of magnetic observatories." Geoscientific Instrumentation, Methods and Data Systems 6, no. 2 (September 25, 2017): 361–66. http://dx.doi.org/10.5194/gi-6-361-2017.
Full textAbstract:
Abstract. The goal of magnetic observatories is to measure and provide a vector magnetic field in a geodetic coordinate system. For that purpose, instrument set-up and calibration are crucial. In particular, the scale factor and orientation of a vector magnetometer may affect the magnetic field measurement. Here, we highlight the baseline concept and demonstrate that it is essential for data quality control. We show how the baselines can highlight a possible calibration error. We also provide a calibration method based on high-frequency absolute measurements. This method determines a transformation matrix for correcting variometer data suffering from scale factor and orientation errors. We finally present a practical case where recovered data have been successfully compared to those coming from a reference magnetometer.
36
Andersen, Ole Baltazar, Shengjun Zhang, David T. Sandwell, Gérald Dibarboure, Walter H. F. Smith, and Adili Abulaitijiang. "The Unique Role of the Jason Geodetic Missions for high Resolution Gravity Field and Mean Sea Surface Modelling." Remote Sensing 13, no. 4 (February 11, 2021): 646. http://dx.doi.org/10.3390/rs13040646.
Full textAbstract:
The resolutions of current global altimetric gravity models and mean sea surface models are around 12 km wavelength resolving 6 km features, and for many years it has been difficult to improve the resolution further in a systematic way. For both Jason 1 and 2, a Geodetic Mission (GM) has been carried out as a part of the Extension-of-Life phase. The GM for Jason-1 lasted 406 days. The GM for Jason-2 was planned to provide ground-tracks with a systematic spacing of 4 km after 2 years and potentially 2 km after 4 years. Unfortunately, the satellite ceased operation in October 2019 after 2 years of Geodetic Mission but still provided a fantastic dataset for high resolution gravity recovery. We highlight the improvement to the gravity field which has been derived from the 2 years GM. When an Extension-of-Life phase is conducted, the satellite instruments will be old. Particularly Jason-2 suffered from several safe-holds and instrument outages during the GM. This leads to systematic gaps in the data-coverage and degrades the quality of the derived gravity field. For the first time, the Jason-2 GM was “rewound” to mitigate the effect of the outages, and we evaluate the effect of “mission rewind” on gravity. With the recent successful launch of Sentinel-6 Michael Freilich (S6-MF, formerly Jason CS), we investigate the possibility creating an altimetric dataset with 2 km track spacing as this would lead to fundamental increase in the spatial resolution of global altimetric gravity fields. We investigate the effect of bisecting the ground-tracks of existing GM to create a mesh with twice the resolution rather than starting all over with a new GM. The idea explores the unique opportunity to inject Jason-3 GM into the same orbital plane as used for Jason-2 GM but bisecting the existing Jason-2 tracks. This way, the already 2-years Jason-2 GM could be used to create a 2 km grid after only 2 years of Jason-3 GM, rather than starting all over with a new GM for Jason-3.
37
Schutz, B. E. "New Observational Techniques and Precise Orbit Determination of Artificial Satellites." International Astronomical Union Colloquium 165 (1997): 79–85. http://dx.doi.org/10.1017/s025292110004639x.
Full textAbstract:
AbstractModern observational techniques using ground-based and space-based instrumentation have enabled the measurement of the distance between the instrument and satellite to better than one centimeter. Such high precision instrumentation has fostered applications with centimeter-level requirements for satellite position knowledge. The determination of the satellite position to such accuracy requires a comparable modeling of the forces experienced by the satellite, especially when classical orbit determination methods are used. Geodetic satellites, such as Lageos, in conjunction with high precision ground-based laser ranging, have been used to improve for modeling of forces experienced by the satellite. Space-based techniques, such as Global Positioning System (GPS), offer alternatives, including kinematic techniques which require no modeling of the satellite forces, or only rudimentary models. This paper will describe the various techniques and illustrate the accuracies achieved with current satellites, such as TOPEX/POSEIDON, GPS/MET and the expectations for some future satellites.
38
Davis, Earl, Keir Becker, Masanori Kyo, and Toshinori Kimura. "Foundational Experiences and Recent Advances in Long-Term Deep-Ocean Borehole Observatories for Hydrologic, Geodetic, and Seismic Monitoring." Marine Technology Society Journal 52, no. 5 (September 1, 2018): 74–86. http://dx.doi.org/10.4031/mtsj.52.5.4.
Full textAbstract:
AbstractFor nearly three decades, various phases of the scientific Ocean Drilling Programs have deployed sealed-hole observatories in deep-ocean boreholes for long-term subseafloor monitoring to address a range of hydrologic and geodynamic objectives. We summarize the scientific motivation for these observatories and review some important early results from those installed in young oceanic crust and subduction zones. We also summarize the evolution of the borehole observatory designs and associated instrumentation, from simple single-interval installations with autonomous low-rate temperature and pressure monitoring to recent multiple-zone installations with sophisticated downhole instrument packages connected to seafloor cabled networks that provide power and high-rate, real-time data access. We emphasize recent advances, illustrated with example data drawn mainly from transects of borehole observatories offshore Japan and Cascadia. These examples illustrate the value of borehole observatory data in resolving a wide range of crustal geodynamic responses from long periods of gradual geodetic change and accumulation of stress to episodes of rapid deformation associated with both seafloor spreading and subduction processes.
39
Matuła, Rafał, and Paulina Lewińska. "Geodetic survey as a means of improving fast MASW (Multichannel Analysis Of Surface Waves) profiling in difficult terrain/land conditions." E3S Web of Conferences 26 (2018): 00007. http://dx.doi.org/10.1051/e3sconf/20182600007.
Full textAbstract:
This paper revolves around newly designed and constructed system that can make 2D seismic measurement in natural, subsoil conditions and role of land survey in obtaining accurate results and linking them to 3D surface maps. A new type of land streamer, designed for shallow subsurface exploration is described in this paper. In land seismic data acquisition methods a vehicle tows a line of seismic cable, lying on construction called streamer. The measurements of points and shots are taken while the line is stationary, arbitrary placed on seismic profile. Exposed land streamer consists of 24 innovatory gimballed 10 Hz geophones. It eliminates the need for hand ‘planting’ of geophones, reducing time and costs. With the use of current survey techniques all data obtained with this instrument are being transferred in to 2D and 3D maps. This process is becoming more automatic.
40
Poshekhonov, V., V. Eremeev, А. Kuznetcov, and A. Kochergin. "MODELS FOR PHOTOGRAMMETRIC PROCESSING OF INFORMATION FROM “RESOURCE-P” SATELLITES." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B6 (June 17, 2016): 169–71. http://dx.doi.org/10.5194/isprs-archives-xli-b6-169-2016.
Full textAbstract:
The present paper provides information about imagery and navigation systems of the Russian high resolution satellites "Resource- P". Models of image geolocation used for photogrammetric processing of information from all types of imagery systems are designed. Design of these models is based on two task solutions: correct processing of the measurement information and geometric calibration of the imagery systems. <br><br> It is shown that for high-precision interior orientation parameters adjustment of the high-resolution "Geoton" instrument the method of self-calibration should be used. The technology of calibration activities is considered. Distinctive features of calibration of the hyperspectral and wide-swath imagery systems are noted. It is represented in the paper that after calibration the root mean square error (RMSE) of measured geodetic coordinates of objects on images do not exceed 10 m. <br><br> Examples of the obtained models practical application for photogrammetric processing of images from “Resource-P” satellites are shown.
41
Mrówczyńska, Maria. "Elements of an algorithm for optimizing a parameter-structural neural network." Reports on Geodesy and Geoinformatics 101, no. 1 (June 1, 2016): 27–35. http://dx.doi.org/10.1515/rgg-2016-0019.
Full textAbstract:
Abstract The field of processing information provided by measurement results is one of the most important components of geodetic technologies. The dynamic development of this field improves classic algorithms for numerical calculations in the aspect of analytical solutions that are difficult to achieve. Algorithms based on artificial intelligence in the form of artificial neural networks, including the topology of connections between neurons have become an important instrument connected to the problem of processing and modelling processes. This concept results from the integration of neural networks and parameter optimization methods and makes it possible to avoid the necessity to arbitrarily define the structure of a network. This kind of extension of the training process is exemplified by the algorithm called the Group Method of Data Handling (GMDH), which belongs to the class of evolutionary algorithms. The article presents a GMDH type network, used for modelling deformations of the geometrical axis of a steel chimney during its operation.
42
Cooke, Anne-Karin, Cédric Champollion, and Nicolas Le Moigne. "First evaluation of an absolute quantum gravimeter (AQG#B01) for future field experiments." Geoscientific Instrumentation, Methods and Data Systems 10, no. 1 (March 24, 2021): 65–79. http://dx.doi.org/10.5194/gi-10-65-2021.
Full textAbstract:
Abstract. Quantum gravimeters are a promising new development allowing for continuous absolute gravity monitoring while remaining user-friendly and transportable. In this study, we present experiments carried out to assess the capacity of the AQG#B01 in view of future deployment as a field gravimeter for hydrogeophysical applications. The AQG#B01 is the field version follow-up of the AQG#A01 portable absolute quantum gravimeter developed by the French quantum sensor company Muquans. We assess the instrument's performance in terms of stability (absence of instrumental drift) and sensitivity in relation to other gravimeters. No significant instrumental drift was observed over several weeks of measurement. We discuss the observations concerning the accuracy of the AQG#B01 in comparison with a state-of-the-art absolute gravimeter (Micro-g-LaCoste, FG5#228). We report the repeatability to be better than 50 nm s−2. This study furthermore investigates whether changes in instrument tilt and external temperature and a combination of both, which are likely to occur during field campaigns, influence the measurement of gravitational attraction. We repeatedly tested external temperatures between 20 and 30 ∘C and did not find any significant effect. As an example of a geophysical signal, a 100 nm s−2 gravity change is detected with the AQG#B01 after a rainfall event at the Larzac geodetic observatory (southern France). The data agreed with the gravity changes measured with a superconducting relative gravimeter (GWR, iGrav#002) and the expected gravity change simulated as an infinite Bouguer slab approximation. We report 2 weeks of stable operation under semi-terrain conditions in a garage without temperature-control. We close with operational recommendations for potential users and discuss specific possible future field applications. While not claiming completeness, we nevertheless present the first characterization of a quantum gravimeter carried out by future users. Selected criteria for the assessment of its suitability in field applications have been investigated and are complemented with a discussion of further necessary experiments.
43
Ho, Minh Dai, and Sergey V. Muravyov. "Accuracy enhancement of measurand estimate on the base of additive combined measurements." Sensor Review 40, no. 3 (May 7, 2020): 377–83. http://dx.doi.org/10.1108/sr-01-2020-0009.
Full textAbstract:
Purpose The paper aims to develop a method for improving the accuracy of smart sensors (deemed as digital measuring instruments) by organizing combined measurements and processing their results by the parametric adjustment method at heterogeneous dispersion of the random error of the applied regression model. Design/methodology/approach When carrying out combined measurements, the problem of joint processing of measurement results of functionally related quantities must be solved. The function type can be known in advance or obtained experimentally. The number of combined measurements exceeds the number of unknown measured quantities. The redundant measurements can improve the accuracy of estimates of measured values but lead to inconsistency of the measurement results. The problem of inconsistency is solved by the parametric adjustment method, which is rather widely used mainly in the field of geodetic measurements, wherein the parametric equations are linear and the measured quantities are additive. Findings The proposed method allows to reduce the uncertainty of type B of a measurement result, caused by the maximum permissible error of a digital measuring instrument, by 1.2–4 times in comparison with the direct estimation method. Originality/value A compact description of the parametric adjustment method in matrix form is given. Recommendations are given on shaping a sensitivity matrix of functions for the proposed method. The geometric interpretation of the proposed method is considered. The results of the proposed method experimental testing are given when evaluating resistance values.
44
Poshekhonov, V., V. Eremeev, А. Kuznetcov, and A. Kochergin. "MODELS FOR PHOTOGRAMMETRIC PROCESSING OF INFORMATION FROM “RESOURCE-P” SATELLITES." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B6 (June 17, 2016): 169–71. http://dx.doi.org/10.5194/isprsarchives-xli-b6-169-2016.
Full textAbstract:
The present paper provides information about imagery and navigation systems of the Russian high resolution satellites "Resource- P". Models of image geolocation used for photogrammetric processing of information from all types of imagery systems are designed. Design of these models is based on two task solutions: correct processing of the measurement information and geometric calibration of the imagery systems. <br><br> It is shown that for high-precision interior orientation parameters adjustment of the high-resolution "Geoton" instrument the method of self-calibration should be used. The technology of calibration activities is considered. Distinctive features of calibration of the hyperspectral and wide-swath imagery systems are noted. It is represented in the paper that after calibration the root mean square error (RMSE) of measured geodetic coordinates of objects on images do not exceed 10 m. <br><br> Examples of the obtained models practical application for photogrammetric processing of images from “Resource-P” satellites are shown.
45
Romney, Jonathan D. "The Very Long Baseline Array." Symposium - International Astronomical Union 129 (1988): 461–68. http://dx.doi.org/10.1017/s0074180900135272.
Full textAbstract:
The Very Long Baseline Array (VLBA) will be the world's first large-scale dedicated VLBI facility. It is planned as a multipurpose instrument, supporting continuum, spectroscopic, astrometric/geodetic, multi-frequency, bandwidth synthesis, polarization, and pulsar measurements – with a variety of bandwidths, sampling rates, quantization schemes, and multi-band modes. The Array will consist of ten new 25-m precision antennas, in an optimized geographical configuration. Extremely low-noise receivers will support observations with dual polarization in nine frequency bands from 330 MHz to 43 GHz, including almost all conventional VLBI bands. A wideband, high-density recording system will allow unattended operation at a sustained data rate of 128 Mbit/s for 24 hours, and peak rates up to 512 Mbit/s. The VLBA correlator, planned as a 20-station system to support processing of all observations involving the Array, will be by far the largest ever built for VLBI. The Array will be operated remotely, from a new operations and data-reduction center to be built in Socorro, NM.
46
Sužiedelytė-Visockienė, Jūratė. "IMPROVEMENT OF RAILWAY TOPOGRAPHIC PLANS UPDATING TECHNOLOGIES." TRANSPORT 21, no. 2 (June 30, 2006): 119–22. http://dx.doi.org/10.3846/16484142.2006.9638052.
Full textAbstract:
Peculiar technologies on the update of topographic map linear objects to scale 1:500–1:2000 are presented. Due to that resulted peculiarities make aerial photographs, carrying out digital aerial triangulation, renewing the topographical plan. The article deals with the submitted example of the topographic plan exhibiting the renovated railway in the city of Vilnius. The updating has been made on the aerial photograph on 1:4000 scale with the photogrammetric instrument PlaniComp P3. The objects possessing no identification in photogrammetry are measured by means of a geodetic method. The redacting varied objects in a database are drawn with AutoCadsoftware. On the basis of this work it is possible to state that for fast and exact updating of topographic plans a progressive photogrammetric method is recommended. It is advised the edition data base to be made by the same operator who made photogrammetric work. The objects are visible in an aerial photo, but no identifying photogrammetry should be applied locally. Digital, renewed data are necessary for drawing up geo information systems (GIS) of the railway, to be able to make fast decisions of urgent problems.
47
Yetkin, M., and O. Bilginer. "On the application of nature-inspired grey wolf optimizer algorithm in geodesy." Journal of Geodetic Science 10, no. 1 (June 24, 2020): 48–52. http://dx.doi.org/10.1515/jogs-2020-0107.
Full textAbstract:
AbstractNowadays, solving hard optimization problems using metaheuristic algorithms has attracted bountiful attention. Generally, these algorithms are inspired by natural metaphors. A novel metaheuristic algorithm, namely Grey Wolf Optimization (GWO), might be applied in the solution of geodetic optimization problems. The GWO algorithm is based on the intelligent behaviors of grey wolves and a population based stochastic optimization method. One great advantage of GWO is that there are fewer control parameters to adjust. The algorithm mimics the leadership hierarchy and hunting mechanism of grey wolves in nature. In the present paper, the GWO algorithm is applied in the calibration of an Electronic Distance Measurement (EDM) instrument using the Least Squares (LS) principle for the first time. Furthermore, a robust parameter estimator called the Least Trimmed Absolute Value (LTAV) is applied to a leveling network for the first time. The GWO algorithm is used as a computing tool in the implementation of robust estimation. The results obtained by GWO are compared with the results of the ordinary LS method. The results reveal that the use of GWO may provide efficient results compared to the classical approach.
48
Suyarso, Suyarso. "Dinamika dan Evolusi Pantai Probolinggo, Jawa Timur." Oseanologi dan Limnologi di Indonesia 1, no. 1 (May 31, 2016): 19. http://dx.doi.org/10.14203/oldi.2016.v1i1.30.
Full textAbstract:
<strong>Dynamics and Evolution of the Coast of Probolinggo, East Java.</strong> The coastal plain of Probolinggo extends from Tongas Subdistrict in the western part to Kraksaan Subdistrict in the eastern part. The south side is the fertile rice field area, while the north side is the fish pond area. The phenomena of coastal changes in Probolinggo are strongly influenced by the materials supplied from Mount Bromo. This research was conducted in April–May 2012, February 2013, and August 2014 and aimed to gain insight into the coastal dynamics and evolution as well as changes and land cover convertion in Probolinggo. The analysis of coastal changes in Probolinggo from 1973 until 2013 was done using multitemporal landsat imageries, the measurement and drawing of coastal profile were carried out using shokiza geodetic instrument and SeaBird Electronic tide gauge. The results showed that in the western part, the accretion process is still ongoing, while in the eastern part, the accretion speed since 1989 has continued to decline and even some places experienced erosion. The new coastal plain formed by the accretion of marine processes is utilized by the residents as fish ponds, whereas accretion formed by fluvial processes is utilized as rice fields. <br /><br />
49
Rybokas, M., V. Giniotis, P. Petrokeviius, R. Kulvietiene, and D. Brucas. "Performance monitoring of geodetic instruments." Insight - Non-Destructive Testing and Condition Monitoring 48, no. 8 (August 1, 2006): 488–91. http://dx.doi.org/10.1784/insi.2006.48.8.488.
Full text
50
Gabryś, Marta, Katarzyna Kryszyn, and Łukasz Ortyl. "GPR surveying method as a tool for geodetic verification of GESUT database of utilities in the light of BSI PAS128." Reports on Geodesy and Geoinformatics 107, no. 1 (June 25, 2019): 49–59. http://dx.doi.org/10.2478/rgg-2019-0006.
Full textAbstract:
AbstractIntensified investment processes in construction have resulted in increased interest in the methods of efficient detection, verification and location of underground utility networks. In addition to the well-known pipe and cable locating equipment, which has increased its efficiency and reliability through the development of technologies, GPRs are becoming more and more popular.This publication presents the results of the experimental research carried out with the use of GPRs manufactured by two different companies as well as the results of the verification of underground utilities in real conditions. The GPRs have worked in the mode of the real-time location of their own position using the GNSS system or robotic total stations.The GPR (Ground Penetrating Radar) surveys performed on a test field, consisting of 9 pipes with a known position, were aimed at assessing the accuracy of their identification on echograms. The utility line location errors were determined using three different combinations between the GPR and the locating instrument. It allowed the evaluation of the possibility of using these solutions for detection, verification and location of underground utility networks in the light of the Polish legal regulations and the British specification PAS 128.The verification in real conditions was carried out in a typical urban space, characterised by an intense occurrence of underground utilities, that is, sewage systems, gas pipelines and power cables. It was based on the GESUT database captured from the county geodetic and cartographic documentation centre. The results of the visual analysis of the materials captured with the help of two measurement systems were described in detail, however, the verification was carried out only for one set of data. The authors have presented the procedure of processing echograms and detecting the location of pipeline axes based on their vectorisation. The authors of this research paper have performed a numerical analysis of the compliance of the profiles of utility lines with the information from the base map for two variants of the GPR data integration with the coordinates. The authors of this research paper have also presented an alternative concept of capturing the profile of a utility line in the field based on the processing of GPR data in 3D – the so-called C-scan. The conclusions summarise the possible factors affecting the surveying results and the methods of eliminating sources of errors, both for the GPR and geodetic data.