Analysis of radial orbit errors of ERS-1, and the development of super-tailored gravity models
Abstract
The altimetry mission of the future ESA remote sensing satellite ERS-1 requires very accurate orbit solutions, of which in particular the radial position component should have an accuracy of approximately 10 cm. This paper presents some investigations into the possibility of reducing the radial position error due to the earth's gravity field, which is by far the largest contributing error source.
With a detailed harmonic analysis of the ERS-1 orbit a number of gravity field model terms are identified which produce the major radial orbit perturbations. These dominant terms are adjusted in a least-squares orbit determination and parameter estimation procedure using actual SEASAT laser tracking observations and altimeter height measurements. The initial gravity model is the NASA GEM-L2 model derived from satellite tracking data only, with an emphasis on LAGEOS data. The resulting super-tailored model yields a significantly improved radial accuracy relative to GEM-L2, but fails to reach the accuracy of the SEASAT-tailored model PGS-S4. Finally, the SEASAT altimeter residuals and the residuals of the cross-over differences are analyzed in the frequency domain by applying a special filtering technique which separates the major radial orbit error and geoid error contributions.- Publication:
-
Advances in Space Research
- Pub Date:
- 1986
- DOI:
- 10.1016/0273-1177(86)90372-8
- Bibcode:
- 1986AdSpR...6i.183Z
- Keywords:
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- Earth Gravitation;
- Error Analysis;
- Ers-1 (Esa Satellite);
- Gravitational Effects;
- Satellite Altimetry;
- Satellite Orbits;
- Satellite Perturbation;
- Harmonic Analysis;
- Satellite Tracking;
- Seasat Satellites;
- Geophysics