Long Baseline (Transoceanic) Surveying Using the Global Positioning System and Its Broadcast Ephemeris.

摘要

Two Global Positioning System (GPS) receivers were used to simultaneously track GPS satellites on a very long baseline. The baseline was 8344 km and subtended an earth-centered arc of about 85 degrees. Due to the large distance separating the antennas and their location in the Southern Hemisphere, only two satellites of the present GPS constellation were able to be tracked simultaneously at both sites. The receiver antennas were placed over position markers with known absolute position accuracies of about 1 to 2 m. Doppler data and the satellite broadcast ephemerides were collected at both sites for a period of about a month. Weekly and daily estimates of the relative antenna positions were determined. The data were processed using linear least-squares procedures, which held one site fixed and estimated corrections to the assumed coordinates of the second. The baseline length was established with an error of less than 1 part per million (ppm). (Author)