An altemative algorithm for mitigating GPS multipath was presented by integrating unscented Kalman filter （UKF） and wavelet transform with particle filter. Within consideration of particle degeneracy, UKF was taken ...An altemative algorithm for mitigating GPS multipath was presented by integrating unscented Kalman filter （UKF） and wavelet transform with particle filter. Within consideration of particle degeneracy, UKF was taken for drawing particle. To remove the noise from raw data and data processing error, adaptive wavelet filtering with threshold was adopted while data preprocessing and drawing particle. Three algorithms, named EKF-PF, UKF-PF and WM-UKF-PF, were performed for comparison. The proposed WM-UKF-PF algorithm gives better error minimization, and significantly improves performance of multipath mitigation in terms of SNR and coefficient even though it has computation complexity. It is of significance for high-accuracy positioning and non-stationary deformation analysis.展开更多
In order to improve the performance of multipath mitigation in tracking Galileo signals, a new multipath mitigation method named early-late strobe correlator （ELSC） is proposed. By applying the strobe correlator use...In order to improve the performance of multipath mitigation in tracking Galileo signals, a new multipath mitigation method named early-late strobe correlator （ELSC） is proposed. By applying the strobe correlator used widely in global positioning system （GPS） scenarios to Galileo E1 signals, it can be found that the strobe correlator has an undesirable level of performance when the delay of multipath signals is about 0. 5 chip. Combining several strobe correlators, the ELSC can effectively mitigate the multipath effect especially for the multipath signals with the 0. 5 chip delay. The multipath error envelopes between the strobe correlator and the ELSC are compared for Galileo E1 signals. The simulation results indicate that the ELSC performs excellently on multipath mitigation, and can be applied in both Galileo scenarios and GPS scenarios.展开更多
A filter method that combines ensemble empirical modal decomposition(EEMD)and wavelet analysis methods was proposed to separate and correct the global navigation satellite system(GNSS)multipath error more effectively....A filter method that combines ensemble empirical modal decomposition(EEMD)and wavelet analysis methods was proposed to separate and correct the global navigation satellite system(GNSS)multipath error more effectively.In this method,the GNSS signal is first decomposed into several intrinsic mode functions(IMFs)and a residual through EEMD.Then,the IMFs and residual are classified into noise terms,mixed terms,and useful terms according to a combined classification criterion.Finally,the mixed term denoised by wavelet and the useful term are reconstructed to obtain the multipath error and thus enable an error correction model to be built.The measurement data provided by the Curtin GNSS Research Center were used for processing and analysis.Results show that the proposed method can separate multipath error from GNSS data to a great extent,thereby effectively addressing the defects of EEMD and wavelet methods on multipath error weakening.The error correction model established with the separated multipath error has a higher accuracy and provides a certain reference value for research on related signal processing.展开更多
The multi-linear variable separation approach method is very useful to solve (2+1)-dimensional integrable systems. In this letter, we extend this method to solve (1+1)-dimensional Boiti system, (2+1)-dimensional Burge...The multi-linear variable separation approach method is very useful to solve (2+1)-dimensional integrable systems. In this letter, we extend this method to solve (1+1)-dimensional Boiti system, (2+1)-dimensional Burgers system, (2+1)-dimensional breaking soliton system, and (2+1)-dimensional Maccari system. Some new exact solutions are obtained and the universal formula obtained from many (2+1)-dimensional systems is extended or modified.展开更多
基金Project(51174206)supported by the National Natural Science Foundation of ChinaProject(2013AA12A201)supported by the National Hi-tech Research and Development Program of China+1 种基金Project(2012ZDP08)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(SZBF2011-6-B35)supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),China
文摘An altemative algorithm for mitigating GPS multipath was presented by integrating unscented Kalman filter （UKF） and wavelet transform with particle filter. Within consideration of particle degeneracy, UKF was taken for drawing particle. To remove the noise from raw data and data processing error, adaptive wavelet filtering with threshold was adopted while data preprocessing and drawing particle. Three algorithms, named EKF-PF, UKF-PF and WM-UKF-PF, were performed for comparison. The proposed WM-UKF-PF algorithm gives better error minimization, and significantly improves performance of multipath mitigation in terms of SNR and coefficient even though it has computation complexity. It is of significance for high-accuracy positioning and non-stationary deformation analysis.
基金The National Key Technology R&D Program of China during the 11th Five-Year Plan Period(No.2008BAJ11B05)
文摘In order to improve the performance of multipath mitigation in tracking Galileo signals, a new multipath mitigation method named early-late strobe correlator （ELSC） is proposed. By applying the strobe correlator used widely in global positioning system （GPS） scenarios to Galileo E1 signals, it can be found that the strobe correlator has an undesirable level of performance when the delay of multipath signals is about 0. 5 chip. Combining several strobe correlators, the ELSC can effectively mitigate the multipath effect especially for the multipath signals with the 0. 5 chip delay. The multipath error envelopes between the strobe correlator and the ELSC are compared for Galileo E1 signals. The simulation results indicate that the ELSC performs excellently on multipath mitigation, and can be applied in both Galileo scenarios and GPS scenarios.
基金The National Natural Science Foundation of China(No.41974030)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX17_0150).
文摘A filter method that combines ensemble empirical modal decomposition(EEMD)and wavelet analysis methods was proposed to separate and correct the global navigation satellite system(GNSS)multipath error more effectively.In this method,the GNSS signal is first decomposed into several intrinsic mode functions(IMFs)and a residual through EEMD.Then,the IMFs and residual are classified into noise terms,mixed terms,and useful terms according to a combined classification criterion.Finally,the mixed term denoised by wavelet and the useful term are reconstructed to obtain the multipath error and thus enable an error correction model to be built.The measurement data provided by the Curtin GNSS Research Center were used for processing and analysis.Results show that the proposed method can separate multipath error from GNSS data to a great extent,thereby effectively addressing the defects of EEMD and wavelet methods on multipath error weakening.The error correction model established with the separated multipath error has a higher accuracy and provides a certain reference value for research on related signal processing.
文摘The multi-linear variable separation approach method is very useful to solve (2+1)-dimensional integrable systems. In this letter, we extend this method to solve (1+1)-dimensional Boiti system, (2+1)-dimensional Burgers system, (2+1)-dimensional breaking soliton system, and (2+1)-dimensional Maccari system. Some new exact solutions are obtained and the universal formula obtained from many (2+1)-dimensional systems is extended or modified.
