Method for improving Doppler accuracy

Abstract

The invention provides a method for improving Doppler accuracy. The method comprises the following steps of a, Kalman filtering, specifically establishing a dynamic model by using a carrier phase as the observed quantity of a filter, and filtering to obtain a phase rate and a phase secondary change rate; b, overtime compensation, specifically compensating the phase rate obtained by the Kalman filtering, namely adding a compensation value to the phase rate to make the phase rate suitable for the short-time interval characteristic of a tracking loop under high dynamic, wherein the compensation value is obtained by multiplying the phase secondary change rate of the filter by lead time; and c, delay compensation, specifically compensating the phase rate to make the phase rate suitable for thehigh dynamic characteristic, dividing the difference of the estimated phase secondary change rate by a time interval to serve as the input of the filter, filtering by using a first-order Kalman filterto obtain a phase third change rate, and multiplying the phase rate by delay to obtain the compensation value. By adopting the scheme, the accuracy of the carrier phase rate of a receiver can be improved, the noise is well suppressed, and accurate observation information is provided for high-accuracy speed measurement.

Description

technical field [0001] The invention relates to the technical field of digital signal processing in satellite receivers, in particular to a method for improving Doppler precision. Background technique [0002] In the Global Positioning Satellite System (GNSS), there are usually two ways to measure velocity: one is calculated by extracting the carrier phase rate from the carrier phase, and the other is calculated by the instantaneous Doppler raw observations obtained by the receiver tracking loop. The carrier phase given by the tracking loop is more accurate than the Doppler value, and most receivers use the carrier phase to extract the carrier phase rate. The phase noise can be removed by filtering technology, but this will cause a large output delay. In the case of high dynamics, the carrier phase rate changes rapidly, and the delay results in poor accuracy of the result. Therefore, it is necessary to process the phase rate of the filtered output to obtain a high-precision...

AI Technical Summary

Problems solved by technology

[0006] The invention solves the technical problem of how to obtain high-precision phase rate from the carrier phase given by the tracking loop

The present invention uses the carrier phase given by the tracking loop to obtain high-precision phase rate, but the existing technology has the disadvantages of being unable to meet the dynamic environment, having time delay, and a large amount of calculation.

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