Carrier frequency phase calibration method for global navigation satellite system signal simulators

Carrier frequency phase differences of global navigation satellite system (GNSS) signals between multiple antennas are measured in many coordinate and navigation applications. GNSS signal simulators are used for determining and controlling instrumental errors of consumer navigation equipment. Therefore, determining the systematic error of the carrier frequency phase of the generated signals is imperative. On this basis, in this study, a calibration method of GNSS signal simulators based on the refined error model of the generated phase differences between simulator outlets was developed and tested. The proposed method was implemented using a wideband oscilloscope as an analog-to-digital converter. Validation of the simulator calibration method was performed by comparison with the measurement results obtained using the State secondary standard of units of complex transmission coefficients in the range of 0–60 dB and complex reflection coefficients in the range of 0.002–1 in the frequency range of 0.05–65 GHz (registration No. 2.1.ZZT.0210.2015). The proposed simulator calibration method can be used to determine calibration corrections to the phase differences of the carrier frequencies of radio signals reproduced by the simulator with an expanded uncertainty of 1° at a coverage factor of 3. The proposed method provides the required accuracy of generating phase differences of the carrier frequencies of GNSS signals for modern types of simulators.