Evaluation of Three GPS Receivers for use in the GPS Sounder

摘要

Three high performance, geodetic quality, Global Positioning System (GPS)receivers were tested at the Naval Command, Control and Ocean Surveillance Center RDT and E Division to evaluate their use in supporting the GPS Sounder. These tests are focused on comparisons of the signal-to-noise ratio (SNR) of the GPS satellite is either rising or setting on the ocean horizon. Of primary interest is the ability of the receiver to lock onto and track the GPS signals when the satellite is at elevation angles of less than 1 degree. This requirement is unique to the GPS Sounder and is one of the most stressful conditions for receiving processing. In most applications, GPS signals never examined at ground-to-satellite elevation angles of less than about 15 degrees because of multipath effects on signal reception. However, the ability to lock onto and track the GPS signals in the presense of severe multipath conditions is crucial to the success of the GPS Sounder.