Accession Number:

ADA209958

Title:

Feasibility of Millimeter-Accuracy Geodetic Positioning and Vehicle Tracking with Repeater Satellites

Descriptive Note:

Master's thesis 29 Apr 1986-27 Jan 1989

Corporate Author:

MASSACHUSETTS INST OF TECH CAMBRIDGE

Personal Author(s):

Report Date:

1989-01-27

Pagination or Media Count:

76.0

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.

Subject Categories:

  • Geodesy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE