沿海验潮站GNSS观测网BDS与GPS基线处理精度分析

为了评估北斗卫星导航系统（BDS）用于验潮站沉降监测的可靠性和精度，该文利用北海区沿海8个验潮站2022年全年的GPS和BDS观测数据，从基线解标准均方根误差、基线重复性和GPS与BDS基线互差等方面对GPS和BDS解算结果进行对比分析。结果表明，BDS基线解的NRMS值在0.17-0.25之间，GPS基线解的NRMS值在0.18-0.23之间，二者基线解的NRMS值基本相当；GPS基线解的长度和各分量基线重复率平均值要小于BDS，从GNSS网固定误差和比例误差看，GPS和BDS的基线长度重复性精度达到10-8~10-9量级，基线东西和南北分量重复性达到10-9量级，基线垂直分量重复性精度达到10-7~10-8量级。在GPS和BDS基线结果互差方面，GPS解算得到的基线长度均要大于BDS，二者平均差值为10.7mm；东西分量差值最小，其次是南北分量，垂直分量差异最大，南北分量、东西分量和垂直分量差值平均值分别为-8.5mm、-3.7mm和10.6mm。南北分量、东西分量、垂直分量和基线长度差值平均值最大值分别为23.6mm、20.9mm、30.4mm和22.1mm。总体而言，BDS基线与GPS基线结果存在一定的差异，但差值不大，相对于基线长度而言，二者差值在10-8量级，均能够满足长序列高精度数据要求，可用于验潮站沉降监测的需要。

Accuracy analysis of BDS and GPS baseline processing of GNSS observation network in coastal tide gauge station

In order to evaluate the reliability and accuracy of the Beidou satellite navigation system (BDS) for the settlement monitoring of tidal stations, this paper uses the GPS and BDS observation data of 8 tidal stations in the coastal area of Beihai in 2022 to compare and analyze the GPS and BDS solution results from the aspects of baseline solution standard root mean square error, baseline repeatability and GPS and BDS baseline difference. The results show that the NRMS values of BDS baseline solutions are between 0.17 and 0.25, and the NRMS values of GPS baseline solutions are between 0.18 and 0.23. The NRMS values of the two baseline solutions are basically the same. The length of the GPS baseline solution and the average value of the baseline repetition rate of each component are smaller than that of BDS. From the fixed error and proportional error of the GNSS network, the repeatability accuracy of the baseline length of GPS and BDS reaches the order of 10-8~10-9, the repeatability of the east-west and north-south components of the baseline reaches the order of 10-9, and the repeatability accuracy of the vertical component of the baseline reaches the order of 10-7~10-8. In terms of the difference between GPS and BDS baseline results, the baseline length obtained by GPS is greater than that of BDS, and the average difference between the two is 10.7mm. The difference of east-west component is the smallest, followed by north-south component, and the difference of vertical component is the largest. The average difference of north-south component, east-west component and vertical component is ?8.5mm, ?3.7mm and 10.6mm, respectively. The maximum average values of the north-south component, the east-west component, the vertical component and the length difference are 23.6mm, 20.9mm, 30.4mm and 22.1mm, respectively. In general, there are some differences between BDS baseline and GPS baseline results, but the difference is not large. Compared with the baseline length, the difference between the two is in the order of 10-8, which can meet the requirements of long sequence high-precision data and can be used for tide station settlement monitoring.