Abstract:In order to solve the inefficient problem in calculating station coordinates with double-difference positioning, GNSSer PPP mode is introduced to speed up the solution process by multicore parallel operation. The precision of velocity field model is reduced due to the random signal contained in the station velocity, so least-squares collocation is used to estimate the random signal, and the Helmert estimation of variance components is introduced to adjust the unreasonable relationship between the noise covariance matrix and the signal covariance matrix. Then, a more accurate velocity field model can be established. Taking the continuously operating reference stations of the CMONOC in Xinjiang from 2011 to 2017 as an example, GNSSer PPP mode is used to obtain the coordinate time series to improve the efficiency of the calculation. The reliability and efficiency of GNSSer are verified. It is also confirmed that the PPP can obtain the velocity information, which is substantially consistent with the double-difference positioning, the difference is within 1.5 mm/a. The established horizontal velocity field grid model in Xinjiang shows that the movement velocity in Xinjiang is 27.1-34.8 mm/a, and the overall trend is north to east. From southwest to northeast in Xinjiang, the direction of motion is deflected from north to east.
GUO Xinwei,TIAN Jie,NIE Jianliang et al. Establishment of Horizontal Velocity Field Grid Model in Xinjiang Based on Precise Point Positioning and Adaptive Least-Squares Collocation[J]. jgg, 2019, 39(10): 1058-1062.