BeiDou navigation satellite system with global coverage(BDS-3)has been fully operational since July 2020,currently providing the positioning,navigation and timing service together with regional BDS-2.In addition to th...BeiDou navigation satellite system with global coverage(BDS-3)has been fully operational since July 2020,currently providing the positioning,navigation and timing service together with regional BDS-2.In addition to the legacy signals of B1I and B3I,the BDS-3 also transmits several new signals such as BIC,B2a and B2b,which brings new opportunities for rapid ambiguity resolution(AR)of BDS precise point positioning(PPP).In this contribution,a multi-frequency(MF)rapid PPP-AR method with regional network augmentation was proposed.Firstly,BDS five-frequency observations were introduced into uncombined double-differenced models to retrieve regional augmentation corrections at the server.Thereafter,a cascade PPP-AR strategy using extra-wide-lane,wide-lane and narrow-lane ambiguity was employed at the user.Once ambiguities were fixed to integers,the phase correction accuracy could reach about 3 cm on average overall BDS frequencies in the network with inter-station distances of 100-200 km.Subsequently,the statistical results of seven-day simulated kinematic experiments showed that over 99% of epochs on average realized PPP-AR.Correspondingly,the positioning accuracy of the MF fixed solution reached 1.8,1.9,4.7 cm in the east,north and up components,respectively,improving by 5-15% compared with the dual-frequency scheme.Moreover,several vehicle-borne experiments under different urban scenarios were also conducted.Under an open-sky or a relatively open highway scene,the BDS-MF scheme similarly exhibited good performance,and over 98% of epochs achieved rapid PPP-AR with a positioning accuracy better than 3 cm.More encouragingly,for this BDS-challenged experiment with an average satellite number of 8.6,although only 72.06% of epochs were available due to serious signal blockages caused by overpass,tunnels or tall buildings,the horizontal positioning accuracy could still remain 7 cm on average.展开更多
Since its full operation in 2020,BeiDou Satellite Navigation System(BDS)has provided global services with highly precise Positioning,Navigation,and Timing(PNT)as well as unique short-message communication.More and mor...Since its full operation in 2020,BeiDou Satellite Navigation System(BDS)has provided global services with highly precise Positioning,Navigation,and Timing(PNT)as well as unique short-message communication.More and more academics focus on multi-frequency Precise Point Positioning(PPP)models,but few on BDS fve-frequency PPP models.Therefore,this study using the uncombined and Ionospheric-Free(IF)observations develops fve BDS fve-frequency PPP models and compares them with the traditional dual-frequency model,known as Dual-frequency IF(DF)model.Some biases such as Inter-Frequency Biases(IFB)and Diferential Code Bias(DCB)are also addressed.With the data collected from 20 stations,the BDS dual-and fve-frequency PPP models are comprehensively evaluated in terms of the static and simulated kinematic positioning performances.Besides,the study also analyzes some by-product estimated parameters in fve-frequency PPP models such as Zenith Troposphere Delay(ZTD).The results of experiment show that fve-frequency PPP models have diferent levels of improvement compared with the DF model.In the static mode,the one single Five-Frequency IF combination(FF5)model has the best positioning consequent,especially in the up direction,and in the simulated kinematic mode,the Three Dual-frequency IF combinations(FF3)model has the largest improvement in convergence time.展开更多
基金supported by the National Natural Science Foundation of China[Grant 41774030,Grant 41974027 and Grant 41974029]the Hubei Province Natural Science Foundation of China[Grant 2018CFA081]+1 种基金the frontier project of basic application from Wuhan science and technology bureau[Grant 2019010701011395]the Sino-German mobility programme[Grant No.M-0054].
文摘BeiDou navigation satellite system with global coverage(BDS-3)has been fully operational since July 2020,currently providing the positioning,navigation and timing service together with regional BDS-2.In addition to the legacy signals of B1I and B3I,the BDS-3 also transmits several new signals such as BIC,B2a and B2b,which brings new opportunities for rapid ambiguity resolution(AR)of BDS precise point positioning(PPP).In this contribution,a multi-frequency(MF)rapid PPP-AR method with regional network augmentation was proposed.Firstly,BDS five-frequency observations were introduced into uncombined double-differenced models to retrieve regional augmentation corrections at the server.Thereafter,a cascade PPP-AR strategy using extra-wide-lane,wide-lane and narrow-lane ambiguity was employed at the user.Once ambiguities were fixed to integers,the phase correction accuracy could reach about 3 cm on average overall BDS frequencies in the network with inter-station distances of 100-200 km.Subsequently,the statistical results of seven-day simulated kinematic experiments showed that over 99% of epochs on average realized PPP-AR.Correspondingly,the positioning accuracy of the MF fixed solution reached 1.8,1.9,4.7 cm in the east,north and up components,respectively,improving by 5-15% compared with the dual-frequency scheme.Moreover,several vehicle-borne experiments under different urban scenarios were also conducted.Under an open-sky or a relatively open highway scene,the BDS-MF scheme similarly exhibited good performance,and over 98% of epochs achieved rapid PPP-AR with a positioning accuracy better than 3 cm.More encouragingly,for this BDS-challenged experiment with an average satellite number of 8.6,although only 72.06% of epochs were available due to serious signal blockages caused by overpass,tunnels or tall buildings,the horizontal positioning accuracy could still remain 7 cm on average.
基金This study was funded by the National Key Research and Development Program of China(No.2020YFA0713502)the National Natural Science Foundation of China(NO.41874039)the Natural Science Foundation of Jiangsu Province(NO.BK2019342).
文摘Since its full operation in 2020,BeiDou Satellite Navigation System(BDS)has provided global services with highly precise Positioning,Navigation,and Timing(PNT)as well as unique short-message communication.More and more academics focus on multi-frequency Precise Point Positioning(PPP)models,but few on BDS fve-frequency PPP models.Therefore,this study using the uncombined and Ionospheric-Free(IF)observations develops fve BDS fve-frequency PPP models and compares them with the traditional dual-frequency model,known as Dual-frequency IF(DF)model.Some biases such as Inter-Frequency Biases(IFB)and Diferential Code Bias(DCB)are also addressed.With the data collected from 20 stations,the BDS dual-and fve-frequency PPP models are comprehensively evaluated in terms of the static and simulated kinematic positioning performances.Besides,the study also analyzes some by-product estimated parameters in fve-frequency PPP models such as Zenith Troposphere Delay(ZTD).The results of experiment show that fve-frequency PPP models have diferent levels of improvement compared with the DF model.In the static mode,the one single Five-Frequency IF combination(FF5)model has the best positioning consequent,especially in the up direction,and in the simulated kinematic mode,the Three Dual-frequency IF combinations(FF3)model has the largest improvement in convergence time.
