基于GPS PPK技术确定测深点瞬时潮位及分析

潮位是影响水下地形测量精度的主要误差之一,获取准确的潮位信息直接关系着潮位改正的正确与否。文中基于GPS PPK技术得到的GPS天线大地高,首先经过垂直基准转换,其次利用推算的姿态改正公式以及利用压力式潮位计获取的动态吃水进行姿态与吃水改正,最后采用小波变换进行波浪滤除,得到测深点精密的瞬时潮位。以琼州海峡为试验海区,采用上述方法获得测深点瞬时潮位,并与传统潮汐模型推算潮位对比,对比发现两者并不一致,且前一种方法得到的潮位趋势与测船的航向有很强的相关性。对测区的潮汐潮流特征进行了分析,分析结果与实测结果相符,表明GPS PPK能够获得该区域的潮位,并可以反映该区域的潮汐特征。

Determination and Analysis of the Instantaneous Tide Level of Sounding Point Based on GPS PPK

Tide level is one of the main errors that affect the accuracy of underwater topographic survey.Accurate tide level information is directly related to the correctness of tide level correction.The ellipsoidal height of GPS antenna obtained based on the GPS PPK technology firstly undergoes vertical reference conversion.Then it uses the estimated attitude correction formula and the dynamic draught obtained by the pressure tide gauge to correct the attitude and draught.Finally,it adopts wavelet transform to perform wave filtering to obtain the precise instantaneous tide level at the sounding point.Taking the Qiongzhou Strait as the experimental sea area,and using the above method to obtain the instantaneous tide level of the sounding point and comparing with the tide level calculated by the traditional tide model,it is found that the two methods are not consistent,and the tide level trend obtained by the former method has a strong correlation with the course of the ship.Through the analysis of tidal current characteristics in the survey area,the analysis results are proved to be consistent with the measured results,which show that GPS PPK can obtain the tide level of the area and reflect the tidal characteristics of the area.