The Study of Gravity Field Estimation Procedures.

1985 ◽  
Author(s):  
Richard H. Rapp
Keyword(s):  
Gravity Field ◽  
Estimation Procedures ◽  
Field Estimation

A simulated gravity field estimation for the main belt comet 133P/Elst-Pizarro

2021 ◽  
Vol 366 (6) ◽  
Author(s):  
Wutong Gao ◽  
Jianguo Yan ◽  
Weitong Jin ◽  
Chen Yang ◽  
Linzhi Meng ◽  
...  
Keyword(s):  
Gravity Field ◽  
Main Belt ◽  
Field Estimation

Impact of low-degree gravity field estimation in the SLR data processing of spherical satellites at AIUB

2021 ◽  
Author(s):  
Linda Geisser ◽  
Ulrich Meyer ◽  
Daniel Arnold ◽  
Adrian Jäggi ◽  
Daniela Thaller
Keyword(s):  
Gravity Field ◽  
Lower Altitude ◽  
Earth’S Gravity Field ◽  
Low Degree ◽  
Station Coordinates ◽  
Earth Rotation Parameters ◽  
Field Estimation ◽  
University Of Bern ◽  
The University ◽  
The Impact

<p>The Astronomical Institute of the University of Bern (AIUB) collaborates with the Federal Agency for Cartography and Geodesy (BKG) in Germany to develop new procedures to generate products for the International Laser Ranging Service (ILRS). In this framework the SLR processing of the standard ILRS weekly solutions of spherical geodetic satellites at AIUB, where the orbits are determined in 7-day arcs together with station coordinates and other geodetic parameters, is extended from LAGEOS-1/2 and the Etalon-1/2 satellites to also include the LARES satellite orbiting the Earth at much lower altitude. Since a lower orbit experiences a more variable enviroment, e.g. it is more sensitive to time-variable Earth's gravity field, the orbit parametrization has to be adapted and also the low degree spherical harmonic coefficients of Earth's gravity field have to be co-estimated. The impact of the gravity field estimation is studied by validating the quality of other geodetic parameters such as geocenter coordinates, Earth Rotation Parameters (ERPs) and station coordinates. The analysis of the influence of LARES on the SLR solution shows that a good datum definition is important.</p>

Determination of Celestial Body Principal Axes via Gravity Field Estimation

2017 ◽  
Vol 40 (12) ◽  
pp. 3050-3060
Author(s):  
Yu Takahashi ◽  
Nicholas Bradley ◽  
Brian Kennedy
Keyword(s):  
Celestial Body ◽  
Gravity Field ◽  
Principal Axes ◽  
Field Estimation

scholarly journals The Role of Non-tidal Atmospheric Loading in the Task of Gravity Field Estimation by Inter-Satellite Measurements

2021 ◽  
Author(s):  
I. O. Skakun ◽  
V. V. Mitrikas ◽  
V. V. Ianishevskii
Keyword(s):  
Gravitational Field ◽  
Gravity Field ◽  
Satellite Measurements ◽  
Atmospheric Loading ◽  
Field Estimation ◽  
Tidal Variations ◽  
Grace Mission ◽  
Monthly Variations ◽  
Water Height

AbstractThe paper reviews models of tidal and non-tidal variations of the Earth's gravitational field. Proposing an algorithm for the estimation of the Stokes coefficients based on inter-satellite measurements of low-orbit spacecrafts. By processing measurements of the GRACE mission, we obtained experimental estimates of gravity field monthly variations. The analysis of these values was carried out by calculating the change in the equivalent water height for a given area.

scholarly journals Combination Analysis of Future Polar-Type Gravity Mission and GRACE Follow-On

2019 ◽  
Vol 11 (2) ◽  
pp. 200 ◽  
Author(s):  
Yufeng Nie ◽  
Yunzhong Shen ◽  
Qiujie Chen
Keyword(s):  
Mass Transport ◽  
Gravity Field ◽  
Combined Model ◽  
Low Latitude ◽  
Orbit Inclination ◽  
Field Estimation ◽  
One Year ◽  
Polar Type ◽  
Gravity Recovery ◽  
Gravity Mission

Thanks to the unprecedented success of Gravity Recovery and Climate Experiment (GRACE), its successive mission GRACE Follow-On (GFO) has been in orbit since May 2018 to continue measuring the Earth’s mass transport. In order to possibly enhance GFO in terms of mass transport estimates, four orbit configurations of future polar-type gravity mission (FPG) (with the same payload accuracy and orbit parameters as GRACE, but differing in orbit inclination) are investigated by full-scale simulations in both standalone and jointly with GFO. The results demonstrate that the retrograde orbit modes used in FPG are generally superior to prograde in terms of gravity field estimation in the case of a joint GFO configuration. Considering the FPG’s independent capability, the orbit configurations with 89- and 91-degree inclinations (namely FPG-89 and FPG-91) are further analyzed by joint GFO monthly gravity field models over the period of one-year. Our analyses show that the FPG-91 basically outperforms the FPG-89 in mass change estimates, especially at the medium- and low-latitude regions. Compared to GFO & FPG-89, about 22% noise reduction over the ocean area and 17% over land areas are achieved by the GFO & FPG-91 combined model. Therefore, the FPG-91 is worthy to be recommended for the further orbit design of FPGs.

scholarly journals Mitigation of ionospheric signatures in Swarm GPS gravity field estimation using weighting strategies

2018 ◽  
Author(s):  
Lucas Schreiter ◽  
Daniel Arnold ◽  
Veerle Sterken ◽  
Adrian Jäggi
Keyword(s):  
Gravity Field ◽  
Systematic Errors ◽  
Low Earth Orbit ◽  
Mitigation Strategies ◽  
Dual Frequency ◽  
Satellite Mission ◽  
Gravity Fields ◽  
Data Gaps ◽  
Field Estimation ◽  
Grace Mission

Abstract. Even though ESA's three-satellite mission Swarm is primarily a magnetic field mission, it became more and more important as gravity field mission. Located in a low earth orbit with altitudes of 460 km for Swarm A and Swarm C and 530 km for Swarm B, after the commissioning phase, and equipped with geodetic-type dual frequency GPS receivers, it is suitable for gravity field computation. Of course the Swarm GPS-only gravity fields are not as good as the gravity fields derived from the ultra precise GRACE K-Band measurements, but due to the end of the GRACE mission in October 2017, data gaps in the previous months, and the gap between GRACE and the recently launched GRACE Follow-On mission, Swarm gravity fields became important to maintain a continuous time series and bridge the gap. By validating the Swarm gravity fields to the GRACE gravity fields, systematic errors have been observed, especially around the geomagnetic equator. These errors are already visible in the kinematic positioning from where they propagate into the gravity field solutions. We investigate these systematic errors by analyzing the geometry-free linear combination of the GPS carrier phase observations. Based on this we present different weighting schemes and investigate their impact on the gravity field solutions in order to assess the success of different mitigation strategies.

scholarly journals Mitigation of ionospheric signatures in Swarm GPS gravity field estimation using weighting strategies

2019 ◽  
Vol 37 (1) ◽  
pp. 111-127 ◽  
Author(s):  
Lucas Schreiter ◽  
Daniel Arnold ◽  
Veerle Sterken ◽  
Adrian Jäggi
Keyword(s):  
Gravity Field ◽  
Systematic Errors ◽  
Low Earth Orbit ◽  
Mitigation Strategies ◽  
Electron Content ◽  
Dual Frequency ◽  
Total Electron ◽  
Gravity Fields ◽  
Field Estimation ◽  
Gravity Recovery

Abstract. Even though ESA's three-satellite low-earth orbit (LEO) mission Swarm is primarily a magnetic field mission, it can also serve as a gravity field mission. Located in a near-polar orbit with initial altitudes of 480 km for Swarm A and Swarm C and 530 km for Swarm B and equipped with geodetic-type dual frequency Global Positioning System (GPS) receivers, it is suitable for gravity field computation. Of course, the Swarm GPS-only gravity fields cannot compete with the gravity fields derived from the ultra-precise Gravity Recovery And Climate Experiment (GRACE) K-band measurements. But for various reasons like the end of the GRACE mission in October 2017, data gaps in the previous months due to battery aging, and the gap between GRACE and the recently launched GRACE Follow-On mission, Swarm gravity fields became important to maintain a continuous time series and to bridge the gap between the two dedicated gravity missions. By comparing the gravity fields derived from Swarm kinematic positions to the GRACE gravity fields, systematic errors have been observed in the Swarm results, especially around the geomagnetic equator. These errors are already visible in the kinematic positions as spikes up to a few centimeters, from where they propagate into the gravity field solutions. We investigate these systematic errors by analyzing the geometry-free linear combination of the GPS carrier-phase observations and its time derivatives using a combination of a Gaussian filter and a Savitzky–Golay filter and the Rate of Total Electron Content (TEC) Index (ROTI). Based on this, we present different weighting schemes and investigate their impact on the gravity field solutions in order to assess the success of different mitigation strategies. We will show that a combination of a derivative-based weighting approach with a ROTI-based weighting approach is capable of reducing the geoid rms from 21.6 to 12.0 mm for a heavily affected month and that almost 10 % more kinematic positions can be preserved compared to a derivative-based screening.

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