一种基于GNSS测高的近海单站水位改正方法

摘要

针对在海洋水深测量或海底地形测量中,部分距岸较远测量区域的水位改正问题,提出一种基于GNSS测高的近海单站水位改正方法,通过对船载GNSS测高数据进行波浪滤波及吃水改正,计算得到反映水位变化的大地高,然后采用最小二乘拟合法,计算测区大地高水位与单验潮站水位的基准面偏差,统一GNSS大地高水位与岸边验潮站基准,从而对测区水深数据进行水位改正.实验表明,该方法可达到厘米级的水位改正精度,满足相关测量规范要求,具有一定的应用价值.%In the small and medium-sized projects for the marine surveys or bathymetric surveys,they often face the situation that the part of the measurement area is far away from the coast with the main features of the inconvenience to lay a tidal station on one side of the sea and a short duration and generally only a few days or more than 10 days.In view of the water level correction for this situation,this paper proposes a method of offshore single water-level correction based on GNSS altimeter.Firstly,the ellipsoidal height reflecting the variation of water level can be calculated according to the shipboard GNSS altimeter data after wave filtering and draft correction.Then,the datum deviation can be obtained using the least square fitting model between the single tidal water level and the ellipsoidai height water level.Finally,the ellipsoidal height water level is converted to the water level whose datum is consistent with the shore tidal station,so that the sounding data can be corrected in the measurement area.Experiments show that accuracy of the water level correction can achieve centimeter level using this method the meet the requirements of the relevant measurement specification and have application value.