Expansion and Improvement of the Israeli Geoid Model by Shipborne GNSS Measurements

The mean sea surface topography of the Ionian and Adriatic Seas has been determined. This was based on six-months of Global Navigation Satellite System (GNSS) measurements which were performed on the Ionian Queen (a ship). The measurements were analyzed following a double-path methodology based on differential GNSS (D-GNSS) and precise point positioning (PPP) analysis. Numerical filtering techniques, multi-parametric accuracy analysis and a new technique for removing the meteorological tide factors were also used. Results were compared with the EGM96 geoid model. The calculated differences ranged between 0 and 48 cm. The error of the results was estimated to fall within 3.31 cm. The 3D image of the marine topography in the region shows a nearly constant slope of 4 cm/km in the N–S direction. Thus, the effectiveness of the approach “repeated GNSS measurements on the same route of a ship” developed in the context of “GNSS methods on floating means” has been demonstrated. The application of this approach using systematic multi-track recordings on conventional liner ships is very promising, as it may open possibilities for widespread use of the methodology across the world.

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Construction of STHA-model of geometric geoid on the Lviv region area

Modern achievements of geodesic science and industry ◽

10.33841/1819-1339-2-42-49-56 ◽

2021 ◽

Vol 42 (II) ◽

pp. 49-56

Author(s):

F. ZABLOTSKYI ◽

◽

B. DZHUMAN ◽

Keyword(s):

Regularization Parameter ◽

Geometric Model ◽

Regional Model ◽

Practical Significance ◽

Independent Data ◽

Geoid Model ◽

Static Mode ◽

High System ◽

Rms Error ◽

Gnss Measurements

Nowadays there is a need to modernize the high system of Ukraine, which requires its integration in the European Vertical Reference System EVRS. In this regard there is also a need to build a regional model of the geoid on the territory of our country, which would be well consistent with the model of the European geoid EGG2015. To obtain the optimal model, it is necessary to use both gravimetric and geometric data. In this case, the model is called gravimetric-geometric. This approach is used both when building a model of the European geoid and when building geoid models on the territory of different European countries. Aim. The purpose of this work is to build a regional geometric STHA-model of the geoid on the Lviv region area and assess its accuracy. In the future it is planned to build a gravimetric STHA-model of the geoid in the same area and compare the results. Methods. To build a geometric STHA-model of the geoid on the Lviv region area, the heights of the geometric geoid, obtained from GNSS-observations at the points of SGN of I, II and III classes, were used. RMS error of determination of geodetic heights , obtained from GNSS leveling in static mode, did not exceed 15 mm. 205 values of the calculated heights of the geoid were used to build the geoid model. 8 values were not involved in the construction of the model, because they were used for an independent assessment of model accuracy. Results. The regional model of geoid within the “Remove–Compute–Restore” procedure with introduction of regularization parameter is obteined. RMS error of the obtained model, calculated on the basis of the data used in its construction, is 12 mm, and on other independent data is 25 mm. Scientific novelty and practical significance. For the first time STHA-functions were tested to build a regional geoid model. The geometric model of the geoid on the Lviv region are is calculated and the accuracy of the obtained model is estimated on the basis of dependent and independent data. The RMS error of the obtained model was about 2 cm, which corresponds to the accuracy of GNSS-measurements. The obtained model can be used as a transformation field on the Lviv region area.

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Extraction of geoid heights from shipborne GNSS measurements along the Weser River in northern Germany

Journal of Geodetic Science ◽

10.1515/jogs-2015-0014 ◽

2015 ◽

Vol 5 (1) ◽

Cited By ~ 4

Author(s):

D. Lavrov ◽

G. Even-Tzur ◽

J. Reinking

Keyword(s):

Measurement Data ◽

Geoid Height ◽

Theoretical Background ◽

Geoid Model ◽

Measuring Techniques ◽

Systematic Effects ◽

Gnss Measurements ◽

Accuracy Assessments

AbstractIn-land geoid models rely on several measuring techniques. The quality of those models is directly related to the spatial resolution of the measurement data. Occasionally, a local geoid model does not cover the coastal area at all and a local marine geoid simply does not exist. ShipborneGNSS measurementsmay provide away of overcoming this problem in coastal areas. However, several corrections to the raw measurements must be applied in order to account for systematic effects induced by ship dynamics and other static and dynamic impacts from tides, atmospheric pressure or wind stress. This paper presents the theoretical background for the method and the results of a case study in the estuary of the Weser River in Germany. A series of GNSS measurements were carried out aboard a ship and the approximate geoid height along the river was derived. For accuracy assessments of this method, the resultswere compared to the German Combined QuasiGeoid 2011 (GCG2011). The results are very promising and indicate the ability to extract geoid heights from shipborne GNSS measurements.

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Development of the One Centimeter Accuracy Geoid Model of Latvia for GNSS Measurements

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/96/1/012037 ◽

2015 ◽

Vol 96 ◽

pp. 012037

Author(s):

J Balodis ◽

G Silabriedis ◽

D Haritonova ◽

M Kaļinka ◽

I Janpaule ◽

...

Keyword(s):

Geoid Model ◽

Gnss Measurements ◽

The One

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HIGH-PRECISION SATELLITE LEVELING AND INVESTIGATION OF THE LOCAL GEOID MODEL IN THE TERRITORY OF KASHKADARYA REGION

EPRA International Journal of Economic Growth and Environmental Issues ◽

10.36713/epra5788 ◽

2020 ◽

pp. 31-35

Author(s):

Fazilova D.Sh ◽

Magdiev H.N ◽

Halimov B.T

Keyword(s):

High Precision ◽

Reference System ◽

Reference Data ◽

Height Anomaly ◽

Geopotential Model ◽

Geoid Model ◽

Geopotential Models ◽

Normal Heights ◽

Gnss Measurements ◽

Local Geoid

In this paper, a study of the accuracy of obtaining normal heights using Global Geopotential Models EGM2008, EIGEN-6C4, GECO and GNSS measurements for the territory of the Kashkadarya region in Uzbekistan is carried out. The heights obtained by the classical leveling in Baltic reference system were used as reference data. EIGEN-6C4 and GECO models were recommended for definition a preliminary quasi  geoid model of the region. KEYWORDS: GNSS and classical leveling, Global Geopotential Model, height anomaly

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New geoid models computation in the Southeast part of Brazil

10.5194/egusphere-egu21-3284 ◽

2021 ◽

Author(s):

Valeria Silva ◽

Gabriel Guimarães ◽

Denizar Blitkow ◽

Ana Cristina Matos

Keyword(s):

Gravity Data ◽

Digital Terrain Model ◽

Minas Gerais ◽

Data Sets ◽

Geoid Model ◽

Terrain Model ◽

Paulo State ◽

Normal Heights ◽

Field Works ◽

Gnss Measurements

<p>In the last decade, big efforts have been undertaken in terms of gravity surveys in the Southeast part of Brazil. First of all, S&#227;o Paulo state has gravity data coverage quite completed in terms of 5&#8217; resolution. Second, in the last few years, some field works have been carried out in Minas Gerais state. The purpose of gravity densification is not only to improve the quality of geoid (quasi-geoid) models in Brazil, but also to contribute to the geodetic infrastructure, in particular, at the moment, for the establishment of the International Height Reference Frame, where two of six planned stations are located in the densification area. These efforts resulted in the computation of two quasi-geoid models in the Southeast region of Brazil. The decision is to compute a quasi-geoid instead of a geoid model, once since 2018, the Brazilian vertical system is based on normal heights. The Minas Gerais model was computed using Least Squares Collocation, via Fast Collocation. The spectral decomposition was employed in the technique for quasi-geoid model computation, where the reference field was represented by XGM2019 up to degree and order 200. The model was compared with GNSS/leveling in order to check the consistency of two different data sets. Two quasi-geoidal models for the S&#227;o Paulo state have been computed. Numerical integration through the Fast Fourier Transform (FFT) was used to perform the integral. The Molodensky gravity anomaly was determined in a 5&#8217; grid, reduced and restored using the Residual Terrain Model (RTM) technique and the XGM2019 with the degree and order 250 and 720. The validation for the S&#227;o Paulo quasi-geoid model is based on the GNSS measurements in the leveling network too.&#160; The Digital Terrain Model SRTM15 plus was used in the continent and the ocean areas in both states.</p>

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