摘要

As BeiDou Navigation Satellite System (BDS) has been operational in the whole Asia-Pacific region, it means a new GNSS system with a different satellite orbit structure will become available for deformation monitoring in the future. Conversely, GNSS deformation monitoring data are always processed with a regular interval to form displacement time series for deformation analysis, where the interval can neither be too long from the time perspective nor too short from the precision of determined displacements angle. In this paper, two experimental platforms were designed, with one being at mid-latitude and another at higher latitude in China. BDS data processing software was also developed for investigating the accuracy of continuous deformation monitoring using current in-orbit BDS satellites. Data over 20 days at both platforms were obtained and were processed every 2,4 and 6 h to generate 3 displacement time series for comparison. The results show that with the current in-orbit BDS satellites, in the mid-latitude area it is easy to achieve accuracy of 1 mm in horizontal component and 2-3 mm in vertical component; the accuracy could be further improved to approximately 1 mm in both horizontal and vertical directions when combined BDS/GPS measurements are employed. At higher latitude, however, the results are not as good as expected due to poor satellite geometry, even the 6 h solutions could only achieve accuracy of 4-6 and 6-10 mm in horizontal and vertical components, respectively, which implies that it may not be applicable to very high-precision deformation monitoring at high latitude using the current BDS. With the integration of BDS and GPS observations, however, in 4-h session, the accuracy can achieve 2 mm in horizontal component and 4 mm in vertical component, which would be an optimal choice for high-accuracy structural deformation monitoring at high latitude.