Analysis of GPS P(Y) signal power enhancement based on the observations with a semi-codeless receiver

The Global Position System(GPS)satellites of Block IIR-M and later versions can turn on the signal power enhancement if needed.In recent years,this power enhancement has been triggered several times when the U.S force was involved in local conflicts,which was observed by the monitoring receivers at International GNSS Service(IGS)/international GNSS Monitoring and Assessment System(iGMAS)stations or the high-gain antennas at monitoring ground stations.The specific power enhancement magnitudes with these two observation methods are different.The observations of L1/L2 P(Y)power with a high-gain antenna are accurate,while the observations at IGS/iGMAS stations contain biases.This paper analyses the reasons for the observation biases with monitoring receivers at IGS/iGMAS stations and proposes a method verifying the accurate relation between the observed carrier-to-noise ratio(C/N_(0))data and the real power enhancement magnitudes.When the power enhancement event happens,the observed L1/L2 P(Y)C/N_(0) data at IGS/iGMAS stations can be corrected using the model proposed in this paper.In the analysis,this paper concludes that the power of L1P(Y)increases by about 4.3–5.3 dB and the power of L2P(Y)by about 4.6–5.2 dB in power enhancement events,which matches the designed capability of GPS satellites as well.The results are also verified by the data of high-gain antennas.