Singel-receiver sentinel to interference

Detection of RF interference or jamming that is above the thermal noise floor and below a power that causes loss of position is possible using signal-to-noise measurements from a single commercial-grade L1 GPS receiver. This research forms part of the GNSS Availability Accuracy Reliability and Integrity Assessment for timing and Navigation (GAARDIAN) project, which provides a mesh of sensors to monitor the integrity, reliability, continuity, and accuracy of the locally received GPS or other GNSS and eLoran signals continuously and to detect anomalous conditions such as local interference, differentiating between possible sources of errors such as interference, multipath, satellite errors, or space weather. A polynomial fit between elevation and SNR is then calculated from the remaining data. A second- or third-degree polynomial generally fits the high-elevation data with deviations from the profile at low elevations being primarily due to multipath where interference is not present.