Test and Analysis of Interference Effects on Dual Frequency GNSS Receiver

摘要

High accuracy GNSS receivers generally eliminate ionospheric delay by adopting dual or multi frequency error correction model to obtain desirable positioning results. However, dual-frequency GNSS receivers also face with radio frequency interference (RFI) in actual application, especially in complicated electromagnetic environment. In this paper, the analysis of carrier to noise ratio (C/N_0) and standard deviation of positioning in interference was introduced, and a test on the actual performance of a typical dual-frequency GPS receiver in interference at the two working frequencies was presented. The test results showed that: as the intensity of interference increased, the C/N_0 of signal descends obviously, thereupon the pseudo-range measurement precision for viewed satellites declined, leading to the loss of positioning accuracy. DGPS carrier phase measurement was recommended under interference condition in this article. By the carrier phase differential approach, the measurement error caused in the course of RFI was eliminated, and better results can be achieved if the number of satellites viewed is favorable.