Performance Analysis Of Navigation With Indian Constellation

With the rapid development of GNSS technology and the continuous expansion of various applications,the performance of satellite navigation systems has attracted much attention from users,and has become the focus of competition among various systems.Carrying out the test and evaluation of the performance of the satellite navigation system can not only improve and improve the performance of the satellite navigation system,but also provide a reference for the next development of the system.NavIC is a regional satellite navigation system developed by the Indian Space Research Organization(ISRO).The system completed a seven-star network in April 2016,covering most parts of China.Studying the performance evaluation method of NavIC system and verifying with the measured data can provide support for improving the evaluation index system of the satellite navigation system.The main research work and results of the paper are as follows:1.Describes the development history and basic situation of NavIC satellite navigation system,introduces the composition of NavIC system,including the composition of NavIC system space segment,ground control segment and user segment,the navigation signals and frequency bands used,and the time and coordinate system Wait.Using STK software to simulate the constellation of NavIC system,the coverage of NavIC system,the number of visible satellites,PDOP value and so on were studied.2.Gives the principle method and process of SLR checking satellite orbit,as well as error correction models such as general relativity,satellite centroid compensation,station eccentricity,station coordinates,troposphere and so on which need to be considered in the process of checking satellite orbit.3.The accuracy of the NavIC broadcast orbit was comprehensively evaluated using SLR observation data for a longer period.At the same time,the broadcast ephemeris of BDS,Galileo,GLONASS orbiting satellites and the precision product precision of the WHU analysis center were compared and analyzed.The results show that the accuracy of NavIC broadcast ephemeris is poor,specifically: NavIC system I02,I03,I04,I05 satellite laser residual RMS are 2.5m,1.42 m,1.51 m,1.48 m,except for the first satellite IRNSS-1b The accuracy of NavIC satellite broadcast ephemeris orbits is about 1.5m;BDS-2,BDS-3,Galileo,GLONASS broadcast ephemeris verification accuracy is about 50 cm,10cm,13 cm,40cm.4.Using the measured data of 8 representative stations of MGEX network for 8 days,the positioning performance of the NavIC system in the primary service area,the secondary service area and the territory of China was analyzed.The results show that the NavIC systemcan basically provide navigation and positioning services within 12 m throughout the day to the primary service area,and provide navigation and positioning services within 20 m for most of the day to the secondary service area.The NavIC system can basically provide Urumqi in western China Provide uninterrupted navigation and positioning services within 8m throughout the day,and provide navigation and positioning services within 13 m during most of the day in Wuhan,southern China.