Citation
Abstract
This article describes an error covariance analysis methodology used to investigate different weighting schemes for two-way (coherent) Doppler data in the presence of transmission-media and observing-platform calibration errors. The analysis focuses on orbit-determination performance in the interplanetary cruise phase of deepspace missions, Analytical models for the Doppler observable and for transmissionmedia and observing-platform calibration errors are presented, drawn primarily from previous work. Previously published analytical models have been improved upon by (1) considering the effects of errors in the calibration of radio signal propagation through the troposphere and ionosphere as well as station-location errors; (2) modelling the spacecraft state transition matrix using a more accurate piecewiselinear approximation to represent the evolution of the spacecraft trajectory; and (3) incorporating Doppler data weighting functions that are functions of elevation angle, which reduce the sensitivity of the estimated spacecraft trajectory to troposphere and ionosphere calibration errors. The analysis is motivated by the need to develop suitable weighting functions for two-way Doppler data acquired at 8.4 GHz (X-band) and 32 GHz (Ka-band). This weighting is likely to be different from that in the weighting functions currently in use; the current functions were constructed originally for use with 2.3-GHz (S-band) Doppler data, which are affected much more strongly by the ionosphere than are the higher frequency data.
Details
- Volume
- 42-108
- Published
- February 15, 1992
- Pages
- 2–19
- File Size
- 854.0 KB