Accession Number : ADP004579

Title :   Enhancements to the TTS-502 Time Transfer System,

Corporate Author : STANFORD TELECOMMUNICATIONS INC SANTA CLARA CA

Personal Author(s) : Van Dierendonck,A. J. ; Hua,Q. D.

Report Date : 02 APR 1984

Pagination or Media Count : 21

Abstract : Two years ago STI introduced an affordable, relatively compact time transfer system on the market -- the TTS-502, and described that system at the 1981 PTTI conference. Over the past few months, that system has been improved, and new features have been added. In addition, new options have been made available to further enhance the capabilities of the system. These enhancements include the addition of a positioning algorithm and new options providing a corrected 5 MHz output that is phase coherent with the 1 pps output, and providing an internal Rubidium Oscillator. The Positioning Algorithm was developed because not all time transfer users had the luxury of the Defense Mapping Agency's (DMA) services for determining their position in WGS-72 coordinates. The enhanced TTS-502 determines the GPS position anywhere in the world, independent of how many GPS satellites are concurrently visible. However, convergence time to a solution is inversely proportional to the number of satellites concurrently visible and the quality of frequency standard used in conjunction with the TTS-502. Real World solution results will be presented for a variety of cases and satellite scheduling scenarios. Typically, positioning accuracies were achieved better than 5 to 10 meters r.s.s. using the C/A code only at Sunnyvale, California.

Descriptors :   *POSITION FINDING, *TIME STUDIES, *GLOBAL POSITIONING SYSTEM, COMPUTATIONS, ALGORITHMS, ARTIFICIAL SATELLITES, KALMAN FILTERING

Distribution Statement : APPROVED FOR PUBLIC RELEASE