scholarly journals The Unique Role of Jason-2 Geodetic Mission for High Resolution Gravity Field Modelling

2020 ◽  
Author(s):  
Ole Baltazar Andersen ◽  
Shengjun Zhang ◽  
David T. Sandwell ◽  
Gérald Dibarboure ◽  
Walter H.F. Smith ◽  
...  
Keyword(s):  
High Resolution ◽  
Gravity Field ◽  
Unique Role ◽  
Gravity Field Modelling ◽  
Field Modelling

High-resolution combined global gravity field modelling – The d/o 5,400 XGM2020 model

2020 ◽  
Author(s):  
Philipp Zingerle ◽  
Roland Pail ◽  
Thomas Gruber
Keyword(s):  
High Resolution ◽  
Gravity Field ◽  
Gravity Anomalies ◽  
Normal Equation ◽  
Terrestrial Gravity ◽  
Gravity Field Modelling ◽  
Field Modelling ◽  
Global Gravity ◽  
Very High ◽  
Block Diagonal

<p>Within this contribution we present the new experimental combined global gravity field model XGM2020. Key feature of this model is the rigorous combination of the latest GOCO06s satellite-only model with global terrestrial gravity anomalies on normal equation level, up to d/o 2159, using individual observation weights. To provide a maximum resolution, the model is further extended to d/o 5400 by applying block diagonal techniques.</p><p>To attain the high resolution, the incorporated terrestrial dataset is composed of three different data sources: Over land 15´ gravity anomalies (by courtesy of NGA) are augmented with topographic information, and over the oceans gravity anomalies derived from altimetry are used.  Corresponding normal equations are computed from these data sets either as full or as block diagonal systems.</p><p>Special emphasis is given to the novel processing techniques needed for very high-resolution gravity field modelling. As such the spheroidal harmonics play a central role, as well as the stable calculation of associated Legendre polynomials up to very high d/o. Also, a new technique for the optimal low-pass filtering of terrestrial gravity datasets is presented.</p><p>On the computational side, solving dense normal equation systems up to d/o 2159 means dealing with matrices of the size of about 158TB. Handling with matrices of such a size is very demanding, even for today’s largest supercomputers. Thus, sophisticated parallelized algorithms with focus on load balancing are crucial for a successful and efficient calculation.</p>

Direct BEM for high-resolution global gravity field modelling

2010 ◽  
Vol 54 (2) ◽  
pp. 219-238 ◽  
Author(s):  
Róbert Čunderlík ◽  
Karol Mikula
Keyword(s):  
High Resolution ◽  
Gravity Field ◽  
Gravity Field Modelling ◽  
Field Modelling ◽  
Global Gravity

High-resolution global gravity field modelling by the finite volume method

2014 ◽  
Vol 59 (1) ◽  
pp. 1-20 ◽  
Author(s):  
Zuzana Minarechová ◽  
Marek Macák ◽  
Robert Čunderlík ◽  
Karol Mikula
Keyword(s):  
High Resolution ◽  
Finite Volume Method ◽  
Gravity Field ◽  
Finite Volume ◽  
Gravity Field Modelling ◽  
Field Modelling ◽  
Global Gravity ◽  
Volume Method

scholarly journals Earth’s gravity field modelling based on satellite accelerations derived from onboard GPS phase measurements

2017 ◽  
Vol 91 (9) ◽  
pp. 1049-1068 ◽  
Author(s):  
X. Guo ◽  
P. Ditmar ◽  
Q. Zhao ◽  
R. Klees ◽  
H. H. Farahani
Keyword(s):  
Gravity Field ◽  
Earth’S Gravity Field ◽  
Phase Measurements ◽  
Gravity Field Modelling ◽  
Field Modelling ◽  
Satellite Accelerations

Harmonic Correction for Residual Terrain Modelling (RTM) Technique in Physical Geodesy Applications

2021 ◽  
Author(s):  
Meng Yang ◽  
Xiao-Le Deng ◽  
Min Zhong
Keyword(s):  
Gravity Anomaly ◽  
Gravity Field ◽  
Physical Geodesy ◽  
Geoid Height ◽  
Gravity Field Modelling ◽  
Field Modelling ◽  
Condensation Method ◽  
Residual Terrain Modelling ◽  
Harmonic Correction ◽  
Terrain Modelling

<p>       In physical geodesy, the harmonic correction (HC), as one of the main problems when using residual terrain modelling (RTM), has become a research focus of high-frequency gravity field modelling. Over past decades, though various methods have been proposed to handle the HC issues for RTM technique, most of them focused on the HC for RTM gravity anomaly rather than other gravity functionals, such as RTM geoid height and gravity gradient. In practice, the HC for RTM geoid height was generally assumed to be negligible, but a quantification is yet studied. In this study, besides the highlighted HC for gravity anomaly in previous studies, the expressions of HC terms for RTM geoid height are provided in the framework of the classical condensation method under infinite Bouguer plate approximation. The errors involved by various assumption of the classical condensation method, e.g., mass inconsistency between infinite masses in the HC and limited masses in the RTM, and planar assumption of the Earth’s surface, are further studied. Based on the derived formulas, the quantification of HC for RTM geoid height when reference surface is expanded to degree and order of 2,159 is given. Our results showed the significance of HC for RTM geoid height, with values up to ~10 cm, in cm-level and mm-level geoid determination. With integration masses extending up to a sufficient distance, such as 1° from calculation point for the determination of RTM geoid height, the errors due to an infinite Bouguer plate approximation are neglectable small. The validation through comparison with terrestrial measurements proved that the HC terms provided in this study can improve the accuracy of RTM derived geoid height and are expected to be useful for applications of RTM technique in regional and global gravity field modelling.</p>

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