International Time Comparison by a GPS (Global Positioning System) Timing Receiver,

Tokyo Astronomical Observatory TAO has started a regular reception of the Global Positioning System GPS timing signals for the purpose of a precise international time comparison. A test operation of the GPS receiver was performed from September 1982 to January 1983 and achieved good accuracy in time comparisons. During the test run, a clock comparison was made by a USNO portable clock team and it was compared with the GPS reception. The difference between the comparisons was less than the error in the portable clock comparison. Since April 1983, regular reception of GPS signals has continued and the results in the GPS time error, UTCTAO-GPS, are transmitted every week on the General-electric GE Mark III system. By this means, the cesium clocks in the asian region will be related to TAI with better accuracies. Author