Citation
Abstract
This article summarizes the status of determining the components of observable modeling that may need upgrading in navigation software to take advantage of the higher accuracy potentially available through 32-GHz (Ka-band) range, Doppler, and delta-differential one-way ranging (delta-DOR) measurements. Areas investigated include (1) high-precision station-location models, (2) Earth-orientation models, (3) a light-time solution, and (4) spacecraft dynamics modeling. JPL software used for radio very long baseline interferometry (VLBI) applications in geodynamics and astrometry was a reference for high-accuracy station-location models, and JPL software used in precision gravity-field determination provided other insights to improved observable modeling. The study reveals that station-location models in the navigation software are complete to the centimeter level, with the exception of the ocean loading and diurnal and semi-diurnal variations in UT1 and polar motion. Since the last updates to the station-location models in the navigation software (1991), it has been established that there are additional centimeter-level models of tidal terms in UT1 and polar motion that should be added. Improvements in the light-time solution implemented in the gravity-reduction software should be realized in the next-generation navigation software, in which extended numerical precision in representing time exists. The higher-order dynamical models in the gravity-analysis software are being implemented in the navigation software for the Mars Reconnaissance Orbiter mission.
Keywords
Details
- Volume
- 42-159
- Published
- November 15, 2004
- Pages
- 1–10
- File Size
- 106.2 KB