利用时变潮时差进行水位改正

Water Correction Method Based on Temporal Variation of Tidal Time Difference

针对目前实施时差法水位改正时使用的潮时差未考虑时变现象的影响以及利用潮时差确定水位观测时段选择混乱等问题,提出利用逐时滑动时段确定潮时差以进行水位改正的方法,分析了潮时差时变现象的原因及潮时差逐时滑动时段与逐日独立时段确定结果的差异,推导了时差法水位改正的误差公式。以某海域验潮站为例,进行了水位改正的数据实验,比较了逐时滑动时段与逐日独立时段确定的潮时差的水位改正效果。实验结果表明,利用逐时滑动确定的潮时差进行水位改正,在理论与精度方面均对目前使用的时差法有所完善与提高,尤其在潮差差异较大的海域,改进效果更加显著。

With the technical developments of poisioning and depth detecting,nowadays,the accuracy of sounding results is highly improved than before,while the effect of water correction still stays the same,which makes it become the main restraint for bathymetry precise.It is key to determine tidal time difference between tidal gauges in time-difference method,which is commonly used to conduct water correction.However,the influence of temporal variation of tidal time-difference on water correction is usually ignored,and the time period of observations to determine tidal time-difference is also selected freely.Focusing on these problems,the phenomenon and cause of temporal variation of tidal time-difference are analyzed from the perspective of the merging theory of tidal constituents.Daily determined and hourly determined tidal time differences are compared in value and meaning and the error formula of water correction in time-difference method is educed.Data experiments are conducted in one sea area to show the contrast effect of water correction by using daily and hourly determined time-difference of tide.The research reveals that it is more precise and reasonable to use hourly determined tidal time-difference,than to use daily determined one,which is currently utilized for water correction.