Study On The Key Technologies And Systems Development Of Metrology And Detection For High-Precision GNSS Receivers

Metrology is related to scientific,technological progress,product quality and efficiency.In terms of GNSS product metrology,with the rapid growth of the market share of various GNSS navigation and positioning terminals,its standardization and qualification rate testing is an important work to be carried out.The current conventional static baseline detection methods cannot accurately assess the technical indicators of each state of the GNSS navigation terminal.In addition,compared with static scenes,the transient and spatial changes of GNSS dynamic positioning are significant,and the internal generation mechanism of positioning errors and the external environmental impact are more complicated.To evaluate GNSS positioning performance under dynamic conditions effectively has always been a difficult issue in international research.The accurate detection of the static and dynamic working capabilities of navigation and positioning terminals is an urgent need to ensure the healthy development of the GNSS navigation industry.Based on the above requirements,this essay conducts research on the establishment of a navigation and positioning terminal dynamic detection system.It mainly involves the research of GNSS positioning models,the construction of navigation positioning terminal detection benchmarks,the research of reference standard methods for high-precision GNSS static detection,the navigation terminal dynamic detection technology and system construction,and the development of navigation terminal dynamic detection specifications.Through the improvement and innovation of related positioning models and system construction,a navigation and positioning terminal dynamic detection system that integrates multi-system GNSS data,CORS technology,and INS technology has been established,which improves the reliability and stability of detection.The main work of the paper is as follows:1.Systematic research on multi-frequency and multi-system GNSS fusion positioning modelCompared with single-system GNSS,multi-system data can increase the strength of the model,thereby improving positioning accuracy and stability.In this paper,the multi-system GNSS loose combination model and the tight combination model are studied respectively,and the measured performance is used to verify the positioning performance of the two models.In terms of loosely combined positioning models,a multi-system GNSS pseudo-range single-point positioning model and a differential relative positioning model are described.Experimental verification results show that compared with GPS single system positioning,multi-system GNSS positioning accuracy is significantly improved.Among them,the positioning accuracy in the plane direction is improved by 58.4%,and the positioning accuracy in the elevation direction is increased by 46.7%.In terms of the tight combined positioning model,a compact combined positioning model of the BDS-3 / GPS / GALILEO three-system real-time estimation of system-to-system deviation(DISB)parameters is proposed for the GPS / BDS pseudo-range tight combined positioning model.The verification results show that the pseudo-range DISB parameters are stable and can be corrected in advance in tight combined positioning.The positioning results of the compact combination model in the simulated environment of different observation satellite numbers show that the compact combination model can effectively improve the positioning accuracy,and the effect is particularly obvious when the number of observation satellites is small.When the number of observation satellites is five,the accuracy improvement rate is more than 25%2.Build a multi-technology fusion high-precision space detection benchmarkThe method of establishing CORS benchmark and the algorithm of generating virtual observations of multi-system GNSS are described.The CORS system construction process for dynamic baseline acquisition is explained from the CORS system establishment goals,the establishment methods of each subsystem,and the test methods.The first domestic multi-system multi-frequency CORS system in the metrology and testing industry was built,and it was the first domestic base station to provide reference data for GNSS navigation and positioning terminals.Performance tests on the CORS system show that the system is 100%available at 24 o'clock,the single baseline zero station coordinate deviation is less than 1cm,the average data delay in system communication is less than 10 ms,and the data packet loss rate is less than 0.01%.A method for constructing dynamic and high-precision spatial detection benchmarks based on INS-enhanced GNSS technology is proposed.Including INS combined with GNSS technology for the establishment of high-precision benchmarks,the sources of errors,measurement of errors,and traceability of errors are described in detail.The method of INS-enhanced GNSS benchmarking is described in detail.The user terminal positioning test shows that the internal positioning accuracy of the fusion system is 0.36 cm,0.51 cm,and1.12 cm,and the external accuracy N,E,and U directions are 0.80 cm,0.97 cm,and 1.51 cm..3.A reference standard for high-precision GNSS static detection was proposed.By analyzing the disadvantages of the traditional baseline method to detect receivers,a complete network differential receiver detection parameter index system was established.On the one hand,the receiver indicators are quantified from three stages: single point,floating point,and fixed solution,and the technical indicators of the network differential receiver are comprehensively evaluated.On the other hand,by setting up a zero baseline test environment,the single-difference filtering model method is used to fix the single-difference ambiguity,and through gross error analysis and accuracy statistics of fixed residuals,the gross error detection and observation accuracy evaluation of receivers to be inspected are achieved..4.Integrated high-precision GNSS vehicle dynamic navigation measurement detection system and developed its detection specificationsBased on the establishment of INS-enhanced GNSS benchmarks,through the seamless docking of CORS and high-precision on-board dynamic navigation detection systems,an in-vehicle detection reference system,monitoring and display system,GNSS signal forwarding system,test unit measurement unit,power supply system,Communication system in an integrated measurement and testing platform.The measurement and detection platform has strong stability and high reliability,and can output detection information such as position,attitude,speed,differential age,and satellite observation capability in real time.The test and analysis results show that the functions of the system meet the requirements.In terms of position accuracy,the test results are 0.4cm in plane and 0.8cm in elevation.In terms of attitude accuracy,the pitch angle,roll angle,and heading angle are 0.002 °,0.002 °,and0.008 °;In terms of speed accuracy,the test results are 0.2cm / s horizontally and 0.3cm / s high;reaching millimeter-level positioning accuracy.The experimental analysis of the index of positioning accuracy,attitude accuracy and speed accuracy when the satellite loses lock for10 s and 60 s has verified the reliability of the system.To meet the needs of high-precision dynamic detection of satellite navigation equipment,based on the development of a high-precision GNSS vehicle dynamic measurement detection system,the "High-precision Beidou / GPS positioning terminal dynamic detection specification(recorded draft)" was drafted,which specifies the vehicle-mounted The precision satellite navigation dynamic detection system detects the dynamic performance of global satellite navigation system(GNSS)terminal equipment,testing methods,evaluation standards,etc.,and provides a reference for the standardization and standardization of dynamic positioning measurement detection of domestic satellite navigation positioning terminals.