Evaluation of the 1984 Alaska Global Positioning System campaign with the Bernese GPS Software

During the summer of 1984 five TI-4100 global positioning system (GPS) receivers were used to measure an eight-station network in Alaska and Canada, previously measured with mobile very long baseline interferometry (VLBI) systems, with baselines ranging from 300 km to almost 2700 km. The observations have been processed in the network mode with the Bernese GPS software using orbit improvement techniques. The comparisons of the GPS and VLBI solutions, established through a seven-parameter Helmert transformation, show an agreement of the order of 0.1 ppm for all solutions. No significant scale factor between GPS and VLBI coordinates could be detected. These results demonstrate for the first time the power of orbit improvement in conjunction with network processing of GPS phase observations.