Results 21 to 30 of about 173 (112)
Approximations, Errors, and Misconceptions in the Use of Map Projections
Mathematical Problems in Engineering, Volume 2021, Issue 1, 2021., 2021 Global geodetic techniques currently can provide the user with worldwide millimeter accuracy. Preservation of this degree of accuracy in derived products is far from straightforward and may leave vast room for trouble in the different steps involved in the collection, storing, processing, analysis, and delivering of geospatial information.
Sergio Baselga +2 more
wiley +1 more source
Geoid model validation and topographic bias
Journal of Geodetic Science, 2022 Recently a number of geoid campaigns were performed to verify different types of geoid and quasigeoid modeling techniques. Typically, GNSS-leveling was employed as an independent method, but in some cases zenith camera astronomic deflection data were ...
Sjöberg Lars E.
doaj +1 more source
Development of a precise local quasigeoid model for the city of Krakow – QuasigeoidKR2019
Reports on Geodesy and Geoinformatics, 2020 A geoid or quasigeoid model allows the integration of satellite measurements with ground levelling measurements in valid height systems. A precise quasigeoid model has been developed for the city of Krakow.
Banasik Piotr +3 more
doaj +1 more source
Quasigeoid cục bộ và quasigeoid toàn cầu
Tạp chí Khoa học Đo đạc và Bản đồ, 2010 Như đã biết, dị thường độ cao xác định theo số liệu trọng lực bằng các phương pháp tích phân số, biến đổi Furie nhanh, collocation v.v… liên quan tới quasigeoid toàn cầu tương ứng với hệ thống tham khảo toàn cầu và mặt đẳng thế trung bình trên qui mô toàn cầu đi qua một điểm khởi tính.
Hoàng Lân Phạm, Yu. M Neyman
openaire +2 more sources
Determination of correlation coefficient between geoid-to-quasigeoid separation calculated by the satellite data in Sjöberg’s equation and GPS/Levelling method [PDF]
Geodesy and Cartography, 2018 In this paper, two techniques for calculating the geoid-to-quasigeoid separation are employed. One of them is GPS/Levelling customary method as a criterion where the geoid undulation and height anomaly are computed by subtracting the ellipsoid height ...
Ata Eshaghzadeh +2 more
doaj +1 more source
Geodetski Vestnik, 2022 This study aims to analyze the quality of several local reference quasigeoid surfaces obtained from several Global Geopotential Models (GGM) relative to the official quasigeoid solution of Serbia (SQM2011) and GNSS/dh observations for the territory of ...
Marko D. Stanković +2 more
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A crossvalidation-based comparison of kriging and IDW in local GNSS/levelling quasigeoid modelling
Reports on Geodesy and Geoinformatics, 2022 This study compares two interpolation methods in the problem of a local GNSS/levelling (quasi) geoid modelling. It uses raw data, no global geopotential model is involved.
Ligas Marcin +2 more
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The quasigeoid modelling in New Zealand using the boundary element method
Contributions to Geophysics and Geodesy, 2010 We compile a quasigeoid model at the study area of New Zealand using the boundary element method (BEM). The direct BEM formulation for the Laplace equation is applied to obtain a numerical solution to the linearized fixed gravimetric boundaryvalue ...
Robert ČUNDERLÍK +3 more
doaj +1 more source
The Geodetic Infrastructure of Ungheni District of the Republic of Moldova
Bulletin of the Polytechnic Institute of Jassy: Constructions, Architechture Section, 2021 Starting from 1999 a new geodetic reference system MOLDREF99 based on the ITRF97 and ETRS89 was established in Republic of Moldova. The realization of MOLDREF99 is the national GNSS Network with density about 1 point per 15 sq. km.
Chiriac Vasile, Nuca Dumitru
doaj +1 more source
Remote Sensing, 2021 This article concerns the development of gravimetric quasigeoid and geoid models using the geophysical gravity data inversion technique (the GGI method).
Marek Trojanowicz +3 more
doaj +1 more source