260 likes | 423 Views
Improving Signal in Space (SIS) Performance of BDS Junping Chen, Yize Zhang, Xiuqiang Gong, Yueling Cao, Shanshi Zhou, Sainan Yang, Xiaogong Hu, Bin Wu Shanghai Astronomical Observatory (SHAO) junping@shao.ac.cn http://www.shao.ac.cn/shao_gnss_ac
E N D
Improving Signal in Space (SIS) Performance of BDS Junping Chen, Yize Zhang, Xiuqiang Gong, Yueling Cao, Shanshi Zhou, Sainan Yang, Xiaogong Hu, Bin Wu Shanghai Astronomical Observatory (SHAO) junping@shao.ac.cn http://www.shao.ac.cn/shao_gnss_ac Bo Tang, Li Liu, Rui Guo, Feng He, Xiaoli Wu, Lingfeng Zhu Beijing Satellite Navigation Center
Content • Background & motivation • Challenges in BDS performance improvement • Signal in Space (SIS) performance improvement of BDS • Design of demonstration system • Summary 2
Background & motivation • >30 GPS • >24 GLONASS • 14 BDS • 6 Galileo • 1 QZSS • Interoperability: improve space coverage • Compatibility: frequency compatibility and non-interference David Turner, 2013 3
Background & motivation • SIS performance improvement :GPS Harold Martin, 2014 David Turner, 2013 4
Background & Motivation • SIS performance improvement: GLONASS Sergey Revnivykh,2011 Grigory Stupak,2013 5
Background & Motivation • SIS performance improvement • BDS: constellation & positioning URE Number of visible satellites Yang et al, 2014 6
Challenges in BDS performance improvement • Tracking network • Regionally distributed only IGS MGEX network Chinese regional network 7
Challenges in BDS performance improvement • Data quality • Severe multipath effects 8
Challenges in BDS performance improvement • GEO satellites • IGSO,MEO satellites Orbit overlap 9
BDS SIS performance improvement • Orbits • Solar radiation model, satellite altitude model and arc connection 10
BDS SIS performance improvement • Orbits • Improvement after POD strategy refinement: 20%in average, Maximum 75%; 11
BDS SIS performance improvement • Broadcast clocks • Satellite clock in broadcast is aligned to TS; The clock differences between POD and TS show periodical signals User positioning improvement after broadcast model refinement.3D 22%-59%, 44% in average 12
BDS SIS performance improvement • Ionosphere model • Current model uses 3-order polynomials for amplitude fitting, does not fit to real estimation; tracking network all in north hemisphere 13 13 13 13
BDS SIS performance improvement • Ionosphere model • Modify the function of amplitude; Adding simulated VTECs in south Hemisphere Real estimates GPSK-8 BDS P8 14
BDS SIS performance improvement • Ionosphere Grids • Availability improved by implementing background ION model and introducing GPS data 15
BDS SIS performance improvement • Augmentation system corrections • Orbit corrections; improving SIS in satellite maneuver; Improving PVT performance for regions with few tracking stations. 16
BDS SIS performance improvement • Augmentation system corrections • Pseudo-range based corrections: large noise • Range-phase combined corrections: smooth and small noise 17
BDS SIS performance improvement • Augmentation system corrections • Range-phase combined corrections 18
BDS SIS performance improvement • SISA & Integrity monitoring • SISRE, URA, SISA (GPS,BDS) • SISA is more close to real SIS performance 19
BDS SIS performance improvement • SISA & Integrity monitoring • RAIM: System integrity monitored at tracking stations using Parity method. Detection Identifying 20
BDS SIS performance improvement • SISA & Integrity monitoring • RAIM: System integrity monitored at tracking stations using Parity method. Detection > 2011514 6:00, COCO Identifying 21
Design of demonstration system • Demonstration system SIS performance improvement platform 22 22
Platform • Platform and analysis • http://www.shao.ac.cn/shao_gnss_ac 23
Analysis • Prototype analysis • BDS PPP with cm accuracy • 1.2cmE-W,3.3cmN-S,4.5cmHeight 24
Summary • Challenges in BDS SIS performance improvement • Proposals for BDS SIS performance improvement • We are aiming at improving BDS SIS performance with the goal of decimeter meter UDRE and 1 meter level UERE. • Demonstration system 25
Acknowledgment: 863 projects (No. 2013AA122402,2014AA123102) NSFC project (No. 11273046) http://www.shao.ac.cn/shao_gnss_ac Thank you! 26