Method for fixing hybrid double-difference ambiguity between BDS and GPS

Abstract

The invention provides a method for fixing the hybrid double-difference ambiguity between the BDS and the GPS, and belongs to the technical field of satellite positioning systems and positioning measurement. The method carries out solving through changing the double-difference ambiguity into the difference between single-difference ambiguities, and then enables the single-difference ambiguities taking week as a unit to be projected as the double-difference ambiguity, so as to eliminate the impact from different wavelengths of the BDS and GPS. The method employs an ISB parameter estimation method and can achieve the analysis of the stability of an ISB in real time. After achieving a stable condition, the method enables the ISB to serve as a correction parameter for correcting original observation data, thereby enabling any double-difference ambiguity between the BDS and the GPS to be integral, and achieving the fixing of the double-difference ambiguity between the BDS and the GPS. The method can eliminate the restraint on the solving of base length from the single-difference ambiguity precision of a reference satellite, prevents the change of observation conditions from causing that the existing ISB correction parameters are useless, and is suitable for engineering application.

Description

technical field [0001] The invention belongs to the technical field of satellite positioning systems and positioning measurement, and in particular relates to a method for fixing mixed double-difference ambiguities between BDS and GPS systems. Background technique [0002] The combination of Beidou Navigation satellite system (BDS) and GPS system can improve the accuracy, reliability and usability of positioning. Due to the increase in the number of observable satellites, the combination of BDS and GPS signals can effectively shorten the initialization time and extend the baseline solution length. [0003] In the process of BDS / GPS combined relative positioning, the established mathematical model usually needs to select one reference satellite in each system, and the ambiguity is fixed in each system respectively. This solution method can be called standard double difference. This method is currently widely used. On the other hand, if BDS and GPS only select one reference ...

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Problems solved by technology

However, this method requires the single-difference ambiguity of the reference satellite to meet a certain accuracy requirement (if GPS satellites are selected as the reference satellite, for B1 / L1 and B2 / L2, the calculation accuracy of the single-difference ambiguity of the reference satellite should be lower than 11 weeks and 6 weeks), for the short baseline, the reference satellite single-difference ambiguity that can meet the accuracy requirements can be calculated according to the multi-epoch P code and carrier phase data; but for the medium-long baseline or long baseline, it is difficult to use effective The method to calculate the reference satellite single-difference ambiguity that meets the accuracy requirements

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