Key Laboratory of Earthquake Prediction, Institute of Earthquake Forecasting, China Earthquake Administration, Beijing 100036, China.
College of Surveying and Geo-Informatics, Tongji University, Shanghai 200092, China.
Sensors (Basel). 2018 Oct 8;18(10):3353. doi: 10.3390/s18103353.
The Crustal Movement Observation Network of China (CMONOC) has begun receiving BeiDou Navigation Satellite System (BDS) observations since 2015, and accumulated more than 2.5 years of data. BDS observations has been widely applied in many fields, and long-term continuous data provide a new strategy for the study of crustal deformation in China. This paper focuses on the evaluation of BDS positioning performance and its potential application on crustal deformation in CMONOC. According to the comparative analysis on multipath delay (MPD) and signal to noise ratio (SNR) between BDS and GPS data, the data quality of BDS is at the same level with GPS measurements in COMONC. The spatial distribution of BDS positioning accuracy evaluated as the root mean square (RMS) of daily residual position time series on horizontal component is latitude-dependent, declining with the increasing of station latitude, while the vertical one is randomly distributed in China. The mean RMS of BDS position residual time series is 7 mm and 22 mm on horizontal and vertical components, respectively, and annual periodicity in position time series can be identified by BDS data. In view of the accuracy of BDS positioning, there are no systematic differences between GPS and BDS results. Based on time series analysis with data volume being 2.5 years, the noise characteristics of BDS daily position time series is time-correlated and corresponding noise is white plus flicker noise model, and the derived mean RMS of the BDS velocities is 1.2, 1.5, and 4.1 mm/year on north, east, and up components, respectively. The imperfect performance of BDS positioning relative to GPS is likely attributed to the relatively low accuracy of BDS ephemeris, and the sparse amount of MEO satellites distribution in the BDS constellation. It is expectable to study crustal deformation in CMONOC by BDS with the gradual maturity of its constellation and the accumulation of observations.
中国地壳运动观测网络（CMONOC）自 2015 年开始接收北斗导航卫星系统（BDS）观测，积累了超过 2.5 年的数据。BDS 观测已广泛应用于许多领域，长期连续的数据为中国地壳变形研究提供了新的策略。本文重点评价了 BDS 定位性能及其在 CMONOC 地壳变形研究中的应用潜力。通过对 BDS 和 GPS 数据的多路径延迟（MPD）和信噪比（SNR）的对比分析，表明 BDS 数据质量与 COMONC 中的 GPS 测量相当。基于水平分量日残差位置时间序列均方根（RMS）评估的 BDS 定位精度的空间分布与站纬度有关，随着站纬度的增加而降低，而垂直分量则在中国随机分布。BDS 位置残差时间序列的平均 RMS 在水平和垂直分量上分别为 7mm 和 22mm，并且可以通过 BDS 数据识别位置时间序列的年周期。从 BDS 定位精度来看，GPS 和 BDS 结果之间没有系统差异。基于 2.5 年的数据量时间序列分析，BDS 日位置时间序列的噪声特征具有时间相关性，相应的噪声为白噪声加闪烁噪声模型，BDS 速度的平均 RMS 分别为 1.2、1.5 和 4.1mm/年，在北、东和向上分量上。BDS 定位相对于 GPS 的不完善性能可能归因于 BDS 星历的相对较低精度，以及 BDS 星座中 MEO 卫星分布的稀疏性。随着其星座的逐渐成熟和观测数据的积累，有望通过 BDS 研究 CMONOC 的地壳变形。
