C/N0 Estimator Based on the Adaptive Strong Tracking Kalman Filter for GNSS Vector Receivers

摘要

The carrier-to-noise ratio ( ) is an important indicator of the signal quality of global navigation satellite system receivers. In a vector receiver, estimating using a signal amplitude Kalman filter is a typical method. However, the classical Kalman filter (CKF) has a significant estimation delay if the signal power levels change suddenly. In a weak signal environment, it is difficult to estimate the measurement noise for CKF correctly. This article proposes the use of the adaptive strong tracking Kalman filter (ASTKF) to estimate . The estimator was evaluated via simulation experiments and a static field test. The results demonstrate that the ASTKF estimator can track abrupt variations in and the method can estimate the weak signal correctly. When jumps, the ASTKF estimation method shows a significant advantage over the adaptive Kalman filter (AKF) method in terms of the time delay. Compared with the popular algorithms, the narrow-to-wideband power ratio (NWPR) method, and the variance summing method (VSM), the ASTKF estimator can adopt a shorter averaging time, which reduces the hysteresis of the estimation results.