Impact of Satellite Elevation Mask in GPS+Galileo RTK Positioning

Global Navigation Satellite Systems (GNSS) have become the keystone and main information supplier for Positioning, Navigation and Timing (PNT) data. While providing an adequate open sky performance, the accuracy of standard code-based GNSS techniques is insufficient for applications requiring precise navigation. Additionally, GNSS positioning algorithms performance can be easily disturbed in signal-degraded environments due to space weather events, obstacles, urban areas, bridges, limited open sky view and/or low-elevation multipath effects. Hence, this study gives a comparative of the performance assessment for different high elevation masks of a multi-frequency multi-GNSS RTK method in a loose combination (a pivot satellite is chosen for each constellation and frequency) to avoid the case of the lack of coinciding frequencies and based in the code and carrier phase measurements of the integration of multiple GNSS constellations. The analysis of the Ambiguity Dilution of Precision (ADOP) and the number of fixed ratio epochs in both static and dynamic real scenarios, demonstrates that the dual frequency L1/E1+L5/E5a GPS+Galileo RTK positioning solution approach presented in this study has a good performance in terms of reliability, positioning accuracy and availability in comparative with a GPSonly RTK algorithm when high elevation mask values are used.