A high-orbit satellite orbit determination method for receiving extremely weak GNSS signals

Abstract

The invention discloses a quite-weak GNSS signal receiving high-orbit-satellite orbit positioning method. By means of the method, a GNSS ephemeris and celestial navigation information are used, the GNSS satellite visibility is analyzed, and a GNSS signal Doppler frequency range is estimated; the technology that an 8*20-ms coherent integration time matched filer is combined with a navigation message for estimation is used, influences of overturning of the navigation message are avoided, data of the navigation message can be correctly obtained, the problem that a coherent integration value is attenuated due to the code Doppler effect is solved, and open-loop-structure quite-weak GNSS signals with the signal intensity as low as -158 dBm can be accurately captured. Meanwhile, ionized layer delay is compensated, the super-long pseudo-range ambiguity is constructed, and accurate orbit positioning of a high-orbit satellite is achieved. The super-long coherent integration time is used, the signals can be intermittently and accurately captured, the weak signal capturing sensitivity is greatly improved, and the energy losses are reduced.

Description

technical field [0001] The invention relates to the technical field of satellite navigation, in particular to a high-orbit satellite orbit determination method for receiving extremely weak GNSS signals. Background technique [0002] GNSS stands for Global Navigation Satellite System, Global Navigation Satellite System. A satellite navigation receiver acquires and tracks the signals of multiple GNSS satellites and then demodulates the navigation data modulated therein. The satellite navigation receiver uses the ranging code to calculate the relative distance between the GNSS satellite and the user, uses the ephemeris data in the navigation data to solve the satellite position and time model, and then calculates the user's position. [0003] Navigation using GNSS signals (such as GPS, Beidou, GLONASS, etc.) has been widely used in space low-orbit satellites, missiles, and ground targets. When the carrier is running on an orbit higher than the GNSS satellite constellation, th...

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Problems solved by technology

[0007] 2. The signal strength is extremely weak, requiring extremely long integration time: traditional receivers are limited by the navigation data bit rate of 50bps, and the coherent integration time is up to 20ms, and must be synchronized after the signal bit to avoid the impact of data bit jumps

[0008] 3. With the extension of the coherent integration time, the Doppler effect of the code will gradually cause the attenuation of the coherent integration, so it is necessary to find a method to overcome the attenuation of the coherent integration;

[0009] 4. High pseudo-range ambiguity: Since high-orbit satellites are extremely far away from GNSS satellites, the ambiguity of pseudo-range needs to be determined more accurately;

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