view Abstract Citations References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Telstar Synchronization and Ranging Experiments. Markowitz, Wm. ; Lidback, C. A. Abstract Timing experiments via Telstar were carried out by the National Physical Laboratory, Teddington, at Goonhilly Downs, and by the U. S. Naval Observatory, at Andover, Maine, 25 and 27 August 1962. The purpose was to synchronize clocks at the Naval Observatory, Washington, and the Royal Greenwich Observatory, Herstmonceux. Time pulses were transmitted and received at both Goonhilly and Andover. Experiments via Telstar included (a) simultaneous two-way transmissions, (b) retransmission, Goonhilly to Andover to Goonhilly, and (c) Andover to satellite to Andover. A photographic technique used at Andover gave a p.e. of 0.36 ~sec for one photograph. A visual technique used at Goonhilly gave a p.e. of 3 ~sec for a single reading. Clocks were related as follows, in microseconds: Andover/Goonhilly, 1; Washington/Andover, using Loran-C, 1; Herstmonceux/ Goonhilly, using 60 kc/sec time signals, 10. Range data derived from time measurements provide an independent check on the scale of an orbit based solely on angle measurements. The agreement of such range data and an ephemeris furnished by the Goddard Space Flight Center of the National Aeronautics and Space Administration, based on Minitrack, is considered very good. Indicated errors in size of orbit are 0.2 km on 25 August and 1.8 km on 27 August. Publication: The Astronomical Journal Pub Date: 1963 DOI: 10.1086/109044 Bibcode: 1963AJ.....68Q.285M full text sources ADS |