Satellite phase bias estimation with global networks and high-dimensional integer ambiguity fixing

Precise point positioning requires precise knowledge of satellite phase biases, satellite position and satellite clock corrections. In this paper, a method for the estimation of these parameters with a global network of multi-frequency reference stations is presented. It includes a clustering of the reference stations. First, individual satellite phase biases, position and clock corrections are derived for each cluster. Subsequently, the solutions of each cluster are combined. We exploit the integer property of the carrier phase ambiguities and perform an integer decorrelation and fixing within each cluster and also in the multi-cluster combination. The performance of the proposed method is analyzed with Galileo measurements on both E1 and E5a of the IGS stations. We defined 16 clusters and obtained satellite phase biases with an accuracy of better than 2 cm.