The Indian Regional Navigation Satellite System provides accurate positioning service to the users within and around India,extending up to 1500 km.However,when a receiver encounters a Continuous Wave Interference,its ...The Indian Regional Navigation Satellite System provides accurate positioning service to the users within and around India,extending up to 1500 km.However,when a receiver encounters a Continuous Wave Interference,its positioning accuracy degrades,or sometimes it even fails to work.Wavelet Packet Transform(WPT)is the most widely used technique for anti-jamming in Global Navigation Satellite System receivers.But the conventional method suffers from threshold drifting and employs inflexible thresholding functions.So,to address these issues,an efficient approach using Improved Particle Swarm Optimization based Parametric Wavelet Packet Thresholding(IPSO-PWPT)is proposed.Firstly,a new parameter adaptive thresholding function is constructed.Then,a new form of inertia weight is presented to enhance the performance of PSO.Later,IPSO is used to optimize the key parameters of WPT.Finally,the implementation of the IPSO-PWPT anti-jamming algorithm is discussed.The performance of the proposed technique is evaluated for various performance metrics in four jamming environments.The evaluation results manifest the proposed method’s efficacy compared to the conventional WPT in terms of anti-jamming capability.Also,the results show the ability of the new thresholding function to process various signals effectively.Furthermore,the findings reveal that the improved PSO outperforms the variants of PSO.展开更多
The Global Positioning System(GPS)is a GNSS constellation,but GNSS is not always GPS.GPS is one of the GNSS constellations used around the world.The GNSS constellations include GPS(US),QZSS(Japan),Beidou/BDS(China),Ga...The Global Positioning System(GPS)is a GNSS constellation,but GNSS is not always GPS.GPS is one of the GNSS constellations used around the world.The GNSS constellations include GPS(US),QZSS(Japan),Beidou/BDS(China),Galileo(EU),and GLONASS(Russia).In 1999,the European Commission(EC)proposed the European Galileo satellite navigation system for the first time.A four-phase development was proposed,including public and private sector finance.Galileo was intended for both civilian and government use,and is managed and controlled by civil authorities.Galileo is made up of 30 satellites,a number of globally distributed ground stations,and a ground control and monitoring system,all of which are extremely similar to the structure,format,and layout of GPS.In this study,we investigate GPS/GLONASS/Galileo/Beidou/IRNSS/QZSS Navigation Satellite System integration algorithm for long baselines ranging from 1500 km to 3000 km in China,Japan and Mongolia.The positioning performance with GPS/GLONASS/Galileo/BDS/IRNSS/QZSS,GPS-only,Galileo-only,GLONASS-only and BDS-only,etc.is compared in terms of the positioning accuracy.An improvement of positioning accuracy over long baselines can be found with GPS/GLONASS/Galileo/BDS/QZSS/IRNSS compared with that of GPS-only and that of BDS-only.The obtained differences of the two baselines(Topcon Magnet Tools Software(Multi-GNSS)-(CSRS-PPP(GPS/GLONASS),(Trimble-RTX(GPS/GLONASS),(AUSPOS(GPS/GLONASS))Online Processing Software)by using GPS/GLONASS/Galileo/BDS/QZSS/IRNSS signals is between 40 cm and 111.5 cm on three days.展开更多
文摘The Indian Regional Navigation Satellite System provides accurate positioning service to the users within and around India,extending up to 1500 km.However,when a receiver encounters a Continuous Wave Interference,its positioning accuracy degrades,or sometimes it even fails to work.Wavelet Packet Transform(WPT)is the most widely used technique for anti-jamming in Global Navigation Satellite System receivers.But the conventional method suffers from threshold drifting and employs inflexible thresholding functions.So,to address these issues,an efficient approach using Improved Particle Swarm Optimization based Parametric Wavelet Packet Thresholding(IPSO-PWPT)is proposed.Firstly,a new parameter adaptive thresholding function is constructed.Then,a new form of inertia weight is presented to enhance the performance of PSO.Later,IPSO is used to optimize the key parameters of WPT.Finally,the implementation of the IPSO-PWPT anti-jamming algorithm is discussed.The performance of the proposed technique is evaluated for various performance metrics in four jamming environments.The evaluation results manifest the proposed method’s efficacy compared to the conventional WPT in terms of anti-jamming capability.Also,the results show the ability of the new thresholding function to process various signals effectively.Furthermore,the findings reveal that the improved PSO outperforms the variants of PSO.
文摘The Global Positioning System(GPS)is a GNSS constellation,but GNSS is not always GPS.GPS is one of the GNSS constellations used around the world.The GNSS constellations include GPS(US),QZSS(Japan),Beidou/BDS(China),Galileo(EU),and GLONASS(Russia).In 1999,the European Commission(EC)proposed the European Galileo satellite navigation system for the first time.A four-phase development was proposed,including public and private sector finance.Galileo was intended for both civilian and government use,and is managed and controlled by civil authorities.Galileo is made up of 30 satellites,a number of globally distributed ground stations,and a ground control and monitoring system,all of which are extremely similar to the structure,format,and layout of GPS.In this study,we investigate GPS/GLONASS/Galileo/Beidou/IRNSS/QZSS Navigation Satellite System integration algorithm for long baselines ranging from 1500 km to 3000 km in China,Japan and Mongolia.The positioning performance with GPS/GLONASS/Galileo/BDS/IRNSS/QZSS,GPS-only,Galileo-only,GLONASS-only and BDS-only,etc.is compared in terms of the positioning accuracy.An improvement of positioning accuracy over long baselines can be found with GPS/GLONASS/Galileo/BDS/QZSS/IRNSS compared with that of GPS-only and that of BDS-only.The obtained differences of the two baselines(Topcon Magnet Tools Software(Multi-GNSS)-(CSRS-PPP(GPS/GLONASS),(Trimble-RTX(GPS/GLONASS),(AUSPOS(GPS/GLONASS))Online Processing Software)by using GPS/GLONASS/Galileo/BDS/QZSS/IRNSS signals is between 40 cm and 111.5 cm on three days.
