Test results for the WAAS Signal Quality Monitor

The Signal Quality Monitor (SQM) is an integrity monitor for the Wide Area Augmentation System (WAAS). The monitor detects L1 signal waveform deformation of a GPS or a Geosynchronous (GEO) satellite monitored by WAAS should that event occur. When a signal deformation occurs, the L1 correlation function measured by the receiver becomes distorted. The distortion will result in an error in the L1 pseudorange. The size of the error depends on the design characteristics of the user receiver. This paper describes test results for the WAAS SQM conducted using prototype software. There are two groups of test cases: the nominal testing and the negative path testing.