Spaceborne GPS orbit determination method based on adaptive measurement noise variance estimation

Abstract

The invention discloses a spaceborne GPS orbit determination method based on adaptive measurement noise variance estimation. The method comprises steps: (1) according to I and Q paths of signals in a spaceborne GPS receiver tracking loop, a narrowband broadband power ratio method is used to estimate a carrier noise ratio (C / N0) of the signals; (2) according to the C / N0 of a tracking loop in each channel, pseudo distance measurement errors between L1 and L2 dual-frequency signals are calculated; (3) L1 and L2 dual-frequency pseudo distance measurement values are combined to obtain a pseudo distance measurement value rhoIF with no ionosphere delay and the error sigmaIF; and (4) with the rhoIF as an observed quantity, an EKF algorithm is used to estimate the orbit information of the satellite. In the method, the measurement noise variance matrix is adaptively adjusted through monitoring changes of the C / N0 of signals in each channel of the spaceborne GPS receiver in real time, the noise statistical characteristics of the observed quantity can be reflected correctly, defects existing in insufficient priori information and dynamic environment of the traditional fixed design EKF algorithm are overcome, and a higher orbit determination precision can be acquired.

Description

technical field [0001] The invention relates to a satellite-borne GPS orbit determination method, in particular to a satellite-borne GPS orbit determination method based on adaptive measurement noise variance estimation. Background technique [0002] With the development of the Global Positioning System (GPS), a new way is provided for spacecraft navigation and orbit determination. Compared with traditional ground-based orbit determination, spaceborne GPS can provide more accurate and continuous navigation and orbit determination services. Therefore, spaceborne GPS technology has gradually become an effective way to determine the orbit of low-orbit satellites. [0003] At present, according to whether the dynamic information of low-orbit satellites is used or not, spaceborne GPS orbit determination is mainly divided into the following three types: 1) Geometric method, which directly uses the pseudorange information of the spaceborne GPS receiver for positioning calculation, ...

AI Technical Summary

Problems solved by technology

[0005] In order to overcome the problem of the traditional KF orbit determination method in random model parameter values, the present invention proposes a spaceborne GPS orbit determination method based on Adaptive Measurement Noise Variance Estimation (AMNVE), which can According to the receiver carrier noise ratio (Carrier Noise Ratio, C / N 0 ) adaptively adjusts R, so that it can better reflect the noise statistical characteristics of the measured value, and can obtain higher orbit determination accuracy

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