Feasibility of Millimeter-Accuracy Geodetic Positioning and Vehicle Tracking with Repeater Satellites
Abstract
The feasibility of the GeoBeacon system is studied. In this system, low-power radio transmitters are placed on vehicles or at other points whose positions are to be monitored. Tropospheric and ionospheric refraction are also monitored. The number of transmitters is practically unlimited. Signals from all transmitters in view are repeated by satellites to a central site where detection, measurement, and data processing take place. To enable precise geodetic positioning, signals would be emitted at multiple frequencies, including relatively low (e.g., 100 MHz) and relatively high (several GHz) frequencies. The lower frequency signals would aid in the acquisition and tracking of the higher frequency signals in order to reduce transmitter-power requirements. Power requirements are calculated as functions of frequency from 100 MHz to 50 GHz, considering both natural phenomena and interference from accidental and intentional radio transmissions. An algorithm is developed for the selection of frequencies by which aided tracking of the highest frequency signal can be maintained. This algorithm is based on a stochastic description of the kinematic and ionospheric contributions to the received signal frequencies and phases. Discrete Kalman filter equations are derived for estimating the covariances of phase and frequency estimates. Keywords: Satellite geodesy; Satellite positioning; Satellite communications; Repeater satellites; Space geodesy; Radio positioning; Radio interferometry; Radio tracking.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 27, 1989
- Accession Number
- ADA209958
Entities
People
- Laureano A. Cangahuala
Organizations
- Massachusetts Institute of Technology