Research On Key Algorithms For Fast Positioning Of Multimode GNSS In Ultra-short Baseline Network

In recent years,with the development of global navigation satellite system(GNSS),especially the improvement of China's Beidou navigation system of the second generation,the positioning by multi-system satellite has become a hot research topic.The relative positioning of the GNSS receiver's antenna by ultra short baseline network can be got with high precision.Therefore,the research of multimode GNSS ultra short baseline network is of great significance.In the application,High-precision attitude measurement can be gotten by GNSS ultra short baseline network instead of attitude measurement of complex and expensive equipment.It has the potential application.Two main problems of GNSS attitude measurement is greatly to solve the ambiguity fixed and attitude determination.In this paper focuses,we focus on the two problems in the system.The main contents and results of this paper are summarized as follows:1 Study on multimode GNSS ultra short baseline network fast relative positioning solution algorithm.This paper mainly studies the principle and calculation method of multimode GNSS ultra short baseline network,including the principle of data fusion of multi satellite systems,multi-mode measurement equation of the integrated solution.2 Puts forward a priori information constraints based on CLAMBDA algorithm.The establishment of virtual observation equation using GNSS network USBL prior information,pathological weakening of the observation equation,improve the two models above ambiguity success rate is fixed.The further study of LAMBDA algorithm and CLAMBDA algorithm based on prior information,this part of the CLAMBDA algorithm,to to improve the ambiguity search efficiency and success rate.3 The inter station single difference real-time filtering and gesture based multimode GNSS solution model.The GPS system,the three fusion navigation system BDS system and GLONASS system,to increase the number of observation satellite observations,so as to improve the structure,improve the positioning accuracy.The inter station single difference real-time filtering and attitude based on the multimode GNSS calculation model,improve the attitude accuracy and stability.4 Research on MCLAMBDA algorithm of direction cosine matrix based on the constraint of the ambiguity search algorithm.Research on key issues of GNSS attitude measurement and the related algorithm,multi-mode GNSS attitude determination algorithm based on baseline parameters and using the direction cosine matrix based mathematical model is established using the carrier phase and code phase combination respectively,combined with the MCLAMBDA algorithm of direction cosine matrix constraints ambiguity search algorithm,get the attitude measurement results with high accuracy.5 Design a MCLAMBDA algorithm of multi-mode GNSS ultra short baseline network relative positioning and attitude measurement based on the combination of the above calculation software.The baseline solution and attitude measurement algorithm to design a multi-mode GNSS attitude measurement software for baseline solution and attitude measurement.According to the South China Sea measured by GNSS data,by laying in offshore exploration ship GNSS ultra short baseline network experiment results show that the marine environment,attitude measurement software MCLAMBDA algorithm in the fuzzy degree of fixed success rate higher than 95%based on the baseline accuracy of centimeter level,to meet the high accuracy of the attitude measurement requirements.