Citation
Abstract
This article presents an analytic development of the information array obtained with a single tracking pass of phase-delay measurements made from a short baseline interferometer. Phase-delay observations can be made with great precision from two antennas using a single, common distributed frequency standard, hence the name “connected element.” With the information array, closed-form expressions are developed for the error covariance in declination and right ascension. These equations serve as useful tools for analyzing the relative merits of candidate station locations for connected element interferometry (CEI). The navigation performance of a short baseline interferometer located at the Deep Space Network’s (DSN’s) Goldstone complex is compared with that which is presently achievable using Very Long Baseline Interferometry (VLBI) over intercontinental baselines. The performance of an intracomplex pair of short baselines formed by three stations is also investigated, along with the use of a single baseline in conjunction with conventional two-way Doppler data. The phase-delay measurement accuracy and data rate used in the analysis are based on the expected performance of an experimental connected element system presently under construction at Goldstone. The results indicate that the VLBI system that will be used during the Galileo mission can determine the declination and right ascension of a distant spacecraft to an accuracy of 20-25 nrad, while the CEI “triad” system and the combination CEI-Doppler system are both capable of 30-70 nrad performance.
Details
- Volume
- 42-101
- Published
- May 15, 1990
- Pages
- 26–38
- File Size
- 553.4 KB