From Kinematic Orbit Determination to Derivation of Satellite Velocity and Gravity Field

2006 ◽  
pp. 177-192 ◽  
Author(s):  
Dražen Švehla ◽  
Lóránt Földváry
Keyword(s):  
Gravity Field ◽  
Orbit Determination ◽  
Kinematic Orbit ◽  
Satellite Velocity

scholarly journals PPP-based Swarm kinematic orbit determination

2018 ◽  
Author(s):  
Le Ren ◽  
Steffen Schön
Keyword(s):  
Gravity Field ◽  
Orbit Determination ◽  
External Validation ◽  
Ionospheric Scintillation ◽  
Kinematic Orbit ◽  
Cycle Slips ◽  
Gravity Field Recovery ◽  
Swarm Satellites ◽  
Least Squares Adjustment ◽  
Reduced Dynamic

Abstract. ESA's Swarm mission offers excellent opportunities to study the ionosphere and to bridge the gap in gravity field recovery between GRACE and GRACE-FO. In order to contribute to these studies, at IfE Hannover, a software based on Precise Point Positioning (PPP) batch least-squares adjustment is developed for kinematic orbit determination. In this paper, the main achievements are presented. The approach for the detection and repair of cycle slips caused by ionospheric scintillation is introduced, which is based on the Melbourne-Wübbena and ionosphere-free linear combination. The results show that around 95 % cycle slips can be repaired and the majority of the cycle slips occur on L2. After the analysis and careful preprocessing of the observations, one year kinematic orbits of Swarm satellites from Sept., 2015 to Aug., 2016 are computed with the PPP approach. The kinematic orbits are validated with the reduced-dynamic orbits published by ESA in Swarm Level 2 products and the SLR measurements. The differences between our kinematic orbits and ESA reduced-dynamic orbits are at the 1.5 cm, 1.5 cm and 2.5 cm level in the along, cross and radial track, respectively. Remaining systematics are characterised by spectral analyses. The external validation with SLR measurements shows rms errors at the 4 cm level. Finally, fully populated covariance matrices of the kinematic orbits obtained from 30 s, 10 s and 1 s data rate are discussed. It is shown that for data rates larger than 10 s, the correlation should be taken into account when using POD coordinates as input for the gravity field recovery.

scholarly journals PPP-based Swarm kinematic orbit determination

2018 ◽  
Vol 36 (5) ◽  
pp. 1227-1241
Author(s):  
Le Ren ◽  
Steffen Schön
Keyword(s):  
Least Squares ◽  
Gravity Field ◽  
Orbit Determination ◽  
External Validation ◽  
European Space Agency ◽  
Kinematic Orbit ◽  
Cycle Slips ◽  
Swarm Satellites ◽  
Least Squares Adjustment ◽  
Reduced Dynamic

Abstract. The Swarm mission of the European Space Agency (ESA) offers excellent opportunities to study the ionosphere and to provide temporal gravity field information for the gap between the Gravity Recovery and Climate Experiment (GRACE) and its follow-on mission (GRACE-FO). In order to contribute to these studies, at the Institut für Erdmessung (IfE) Hannover, a software based on precise point positioning (PPP) batch least-squares adjustment is developed for kinematic orbit determination. In this paper, the main achievements are presented. The approach for the detection and repair of cycle slips caused by ionospheric scintillation is introduced, which is based on the Melbourne–Wübbena and ionosphere-free linear combination. The results show that around 95 % of cycle slips can be repaired and the majority of the cycle slips occur on L2. After the analysis and careful preprocessing of the observations, 1-year kinematic orbits of Swarm satellites from September 2015 to August 2016 are computed with the PPP approach. The kinematic orbits are validated with the reduced-dynamic orbits published by the ESA in the Swarm Level 2 products and SLR measurements. The differences between IfE kinematic orbits and ESA reduced-dynamic orbits are at the 1.5, 1.5 and 2.5 cm level in the along-track, cross-track and radial directions, respectively. Remaining systematics are characterized by spectral analyses, showing once-per-revolution period. The external validation with SLR measurements shows RMSEs at the 4 cm level. Finally, fully populated covariance matrices of the kinematic orbits obtained from the least-squares adjustment with 30, 10 and 1 s data rate are discussed. It is shown that for data rates larger than 10 s, the correlation between satellite positions should be taken into account, for example, for the recovery of gravity field from kinematic orbits.

Orbit determination of the SELENE satellites using multi-satellite data types and evaluation of SELENE gravity field models

2011 ◽  
Vol 85 (8) ◽  
pp. 487-504 ◽  
Author(s):  
S. Goossens ◽  
K. Matsumoto ◽  
D. D. Rowlands ◽  
F. G. Lemoine ◽  
H. Noda ◽  
...  
Keyword(s):  
Gravity Field ◽  
Satellite Data ◽  
Orbit Determination ◽  
Data Types ◽  
Gravity Field Models

Determination of Polar Motion and Earth Rotation from Laser Tracking of Satellites

1979 ◽  
Vol 82 ◽  
pp. 231-238 ◽  
Author(s):  
David E. Smith ◽  
Ronald Kolenkiewicz ◽  
Peter J. Dunn ◽  
Mark Torrence
Keyword(s):  
Gravity Field ◽  
Radiation Pressure ◽  
Orbit Determination ◽  
Earth Rotation ◽  
Polar Motion ◽  
Ocean Tides ◽  
Earth’S Gravity Field ◽  
Laser Tracking ◽  
Order Of Magnitude

Laser tracking of the Lageos spacecraft has been used to derive the position of the Earth's pole of rotation at 5-day intervals during October, November and December 1976. The estimated precision of the results is 0.01 to 0.02 arcseconds in both x and y components, although the formal uncertainty is an order of magnitude better, and there is general agreement with the Bureau International de l'Heure smoothed pole path to about 0.02 arcseconds. Present orbit determination capability of Lageos is limited to about 25 cm rms fit to data over periods of 5 days and about 50 cm over 50 days. The present major sources of error in the perturbations of Lageos are Earth and ocean tides followed by the Earth's gravity field, and solar and Earth reflected radiation pressure. Ultimate accuracy for polar motion and Earth rotation from Lageos after improved modeling of the perturbing forces appears to be of order ± 5 cm for polar motion over a period of about 1 day and about ± 0.2 to ± 0.3 milliseconds in U.T. for periods up to 2 or 3 months.

scholarly journals Effects of New Level-1B Data on GRACE Temporal Gravity Field Models and Precise Orbit Determination Solutions

2021 ◽  
Vol 13 (20) ◽  
pp. 4119
Author(s):  
Nannan Guo ◽  
Xuhua Zhou ◽  
Kai Li
Keyword(s):  
Gravity Field ◽  
Orbit Determination ◽  
Field Model ◽  
Precise Orbit Determination ◽  
Satellite Orbit ◽  
Data Types ◽  
Gravity Field Model ◽  
Precise Orbit ◽  
Temporal Gravity ◽  
Gravity Field Models

The quality of Gravity Recovery and Climate Experiment (GRACE) observation is the prerequisite for obtaining the high-precision GRACE temporal gravity field model. To study the influence of new-generation GRACE Level-1B Release 03 (RL03) data and the new atmosphere and ocean de-aliasing (AOD1B) products on recovering temporal gravity field models and precise orbit determination (POD) solutions, we combined the global positioning system and K-band ranging-rate (KBRR) observations of GRACE satellites to estimate the effect of different data types on these solutions. The POD and monthly gravity field solutions are obtained from 2005 to 2010 by SHORDE software developed by the Shanghai Astronomical Observatory. The post-fit residuals of the KBRR data were decreased by approximately 10%, the precision of three-direction positions of the GRACE POD was improved by approximately 5%, and the signal-to-noise ratio of the monthly gravity field model was enhanced. The improvements in the new release of monthly gravity field model and POD solutions can be attributed to the enhanced Level-1B KBRR data and the AOD1B model. These improvements were primarily due to the enhanced of KBRR data; the effect of the AOD1B model was not significant. The results also showed that KBRR data slightly improve the satellite orbit precision, and obviously enhance the precision of the gravity field model.

Sign in / Sign up

Export Citation Format

Share Document