The Earth’s surface kinematics and deformation are fundamental to understanding crustal evolution.An effective research approach is to estimate regional motion field and deformation fields based on modern geodetic ne...The Earth’s surface kinematics and deformation are fundamental to understanding crustal evolution.An effective research approach is to estimate regional motion field and deformation fields based on modern geodetic networks.If the discrete observed velocity field is obtained,the velocity related fields,such as dilatation rate and maximum shear strain rate,can be estimated by applying varied mathematical approaches.This study applied Akaike's Bayesian Information Criterion(ABIC)method to calculate strain rate fields constrained by GPS observations in the southeast Tibetan Plateau.Comparison with results derived from other three methods revealed that our ABIC-derived strain rate fields were more precise.The maximum shear strain rate highlighted the Xianshuihe–Xiaojiang fault system as the main boundary for the outward migration of material in southeastern Tibet,indicating rotation of eastern Tibet material around the eastern Himalaya rather than whole extrusion along a fixed channel.Additionally,distinct dilatation rate patterns in the northeast and southwest regions of the fault system were observed.The northeast region,represented by the Longmenshan area,exhibited negative dilatational anomalies;while the southwest region,represented by the Jinsha River area north of 29°N,displayed positive dilatational anomalies.This indicates compression in the former and extension in the latter.Combined with deep geophysical observations,we believe that the upper and lower crusts of the Jinsha River area north of 29°N are in an entire expanding state,probably caused by the escape-drag effect of material.The presence of a large,low-viscosity region south of 29°N may not enable the entire escape of the crust,but instead result in a differential escape of the lower crust faster than the upper crust.展开更多
超宽带UWB(Ultde Wide Band)定位是近几年发展起来的无线定位技术,UWB信号具有抗多径效应好、定位精度和刷新率高等优点,但UWB一般只能用于进行室内高精度定位。而差分GPS(DGPS)的室外定位精度能达到分米级。描述了结合UWB和DGPS(Differ...超宽带UWB(Ultde Wide Band)定位是近几年发展起来的无线定位技术,UWB信号具有抗多径效应好、定位精度和刷新率高等优点,但UWB一般只能用于进行室内高精度定位。而差分GPS(DGPS)的室外定位精度能达到分米级。描述了结合UWB和DGPS(Differential Global Position System)的定位方法,采用融合Savitzky-Golay滤波器与粒子滤波器来解决不同传感器的数据融合,实现室内外的无缝定位切换,应用在需要室内室外联合定位的场合。实验表明,采用融合不同滤波器进行处理后,能有效地提高定位精度。展开更多
The pseudorange residual error of imperfect correction of the ionospheric time delay in pseudorange (PR) differential global positioning system (DGPS) is analyzed. The different vertical total electron content (TEC) a...The pseudorange residual error of imperfect correction of the ionospheric time delay in pseudorange (PR) differential global positioning system (DGPS) is analyzed. The different vertical total electron content (TEC) and slant factors at the pierce points of satellite signals are the reasons of the residual error. An improved pseudorange differential approach is proposed and the effect of this new PR differential operation verified by using the simulation.展开更多
基金supported by grants from the Ministry of Science and Technology(Grant Nos.2021FY100101,2019QZKK0901)the National Natural Science Foundation of China(Grant Nos.41941016,42230312,42020104007)China Geological Survey(Grant No.DD20221630).
文摘The Earth’s surface kinematics and deformation are fundamental to understanding crustal evolution.An effective research approach is to estimate regional motion field and deformation fields based on modern geodetic networks.If the discrete observed velocity field is obtained,the velocity related fields,such as dilatation rate and maximum shear strain rate,can be estimated by applying varied mathematical approaches.This study applied Akaike's Bayesian Information Criterion(ABIC)method to calculate strain rate fields constrained by GPS observations in the southeast Tibetan Plateau.Comparison with results derived from other three methods revealed that our ABIC-derived strain rate fields were more precise.The maximum shear strain rate highlighted the Xianshuihe–Xiaojiang fault system as the main boundary for the outward migration of material in southeastern Tibet,indicating rotation of eastern Tibet material around the eastern Himalaya rather than whole extrusion along a fixed channel.Additionally,distinct dilatation rate patterns in the northeast and southwest regions of the fault system were observed.The northeast region,represented by the Longmenshan area,exhibited negative dilatational anomalies;while the southwest region,represented by the Jinsha River area north of 29°N,displayed positive dilatational anomalies.This indicates compression in the former and extension in the latter.Combined with deep geophysical observations,we believe that the upper and lower crusts of the Jinsha River area north of 29°N are in an entire expanding state,probably caused by the escape-drag effect of material.The presence of a large,low-viscosity region south of 29°N may not enable the entire escape of the crust,but instead result in a differential escape of the lower crust faster than the upper crust.
文摘超宽带UWB(Ultde Wide Band)定位是近几年发展起来的无线定位技术,UWB信号具有抗多径效应好、定位精度和刷新率高等优点,但UWB一般只能用于进行室内高精度定位。而差分GPS(DGPS)的室外定位精度能达到分米级。描述了结合UWB和DGPS(Differential Global Position System)的定位方法,采用融合Savitzky-Golay滤波器与粒子滤波器来解决不同传感器的数据融合,实现室内外的无缝定位切换,应用在需要室内室外联合定位的场合。实验表明,采用融合不同滤波器进行处理后,能有效地提高定位精度。
文摘The pseudorange residual error of imperfect correction of the ionospheric time delay in pseudorange (PR) differential global positioning system (DGPS) is analyzed. The different vertical total electron content (TEC) and slant factors at the pierce points of satellite signals are the reasons of the residual error. An improved pseudorange differential approach is proposed and the effect of this new PR differential operation verified by using the simulation.
