Decimeter-level service is provided by the BeiDou satellite navigation system wide area differential service(BDS WADS)for users who collect carrier phase measurements.However,the fluctuations in Geostationary Earth Or...Decimeter-level service is provided by the BeiDou satellite navigation system wide area differential service(BDS WADS)for users who collect carrier phase measurements.However,the fluctuations in Geostationary Earth Orbit(GEO)satellite orbit errors reduce the spatial correlation of orbit errors.These fluctuations not only decrease the accuracy and stability of zone correction service provided by BDS WADS,but also shorten its effective range.In this paper,we proposed an algorithm to weaken the influence of GEO satellite orbit error fluctuations and verified the method using data from eight sparsely distributed zones.The results show that orbit errors can be stabilized using orbit fluctuation corrections,and the positioning precision and stability of the BDS WADS can be improved simultaneously.Under normal circumstances,the horizontal and vertical positioning accuracy of users within 1000 km from the center of the zone can reach 0.19 m and 0.34 m.Furthermore,the effective range is increased.The positioning performance within 1800 km could reach 0.24 m and 0.38 m for the horizontal and vertical components,respectively.展开更多
A novel offset Fresnel Zone Plate reflector Antenna ( FZPA ) is proposed, the phase correcting zone of this FZPA is elliptic. Based on Physical Optics Method, the focusing characteristics of the reflector are an...A novel offset Fresnel Zone Plate reflector Antenna ( FZPA ) is proposed, the phase correcting zone of this FZPA is elliptic. Based on Physical Optics Method, the focusing characteristics of the reflector are analyzed. The comparison of this new FZPA with the circular FZPA and Mawzones FZPA is made.展开更多
A new type of reflector antenne is proposed, which applies the 1 D Fresnel zone phase correction to the classical parabolic cylindrical reflector, providing an alternative to the dual parabolic cylindrical ones discu...A new type of reflector antenne is proposed, which applies the 1 D Fresnel zone phase correction to the classical parabolic cylindrical reflector, providing an alternative to the dual parabolic cylindrical ones discussed by Sanad and Shafai [1] . The focusing characteristics of the new reflector are analyzed by physical optics method, and numerical results are illustrated to evaluate its applicability.展开更多
基金the National Natural Science Funds of China(Grant No.41604032).
文摘Decimeter-level service is provided by the BeiDou satellite navigation system wide area differential service(BDS WADS)for users who collect carrier phase measurements.However,the fluctuations in Geostationary Earth Orbit(GEO)satellite orbit errors reduce the spatial correlation of orbit errors.These fluctuations not only decrease the accuracy and stability of zone correction service provided by BDS WADS,but also shorten its effective range.In this paper,we proposed an algorithm to weaken the influence of GEO satellite orbit error fluctuations and verified the method using data from eight sparsely distributed zones.The results show that orbit errors can be stabilized using orbit fluctuation corrections,and the positioning precision and stability of the BDS WADS can be improved simultaneously.Under normal circumstances,the horizontal and vertical positioning accuracy of users within 1000 km from the center of the zone can reach 0.19 m and 0.34 m.Furthermore,the effective range is increased.The positioning performance within 1800 km could reach 0.24 m and 0.38 m for the horizontal and vertical components,respectively.
文摘A novel offset Fresnel Zone Plate reflector Antenna ( FZPA ) is proposed, the phase correcting zone of this FZPA is elliptic. Based on Physical Optics Method, the focusing characteristics of the reflector are analyzed. The comparison of this new FZPA with the circular FZPA and Mawzones FZPA is made.
文摘A new type of reflector antenne is proposed, which applies the 1 D Fresnel zone phase correction to the classical parabolic cylindrical reflector, providing an alternative to the dual parabolic cylindrical ones discussed by Sanad and Shafai [1] . The focusing characteristics of the new reflector are analyzed by physical optics method, and numerical results are illustrated to evaluate its applicability.
