Impact of Double Differences Correlation on the Adjustment of Small GNSS Networks

Abstract

The effect of correlations in global navigation satellite system (GNSS) double difference observation has been investigated, and it has been empirically found that such effect is small in local networks (baseline up to a few kilometers). In this work, we show that if the extension of the network is very small (a few kilometers), if all receivers of the network observe the same satellites (no occlusion), and the network baselines are created by the star strategy, the discussed correlations do not have an impact at all on the estimates of the coordinates. The equivalence between the network solution and the single baseline solutions is first derived theoretically and then tested on a small real network. A method to derive the overall covariance matrix of the network from single baseline solutions is given.