单波束测深数据的插值精度分析

基于误差传播定律,对稀疏的离散水深点内插值进行了精度分析,建立了单波束水深内插值中误差表达的数学模型,利用我国南方某海岸带的3个试验区的进行了试验。试验结果表明,反距离加权法、Shepard法和线性插值三角网法,辅以自适应搜索半径法,内插水深值粗差比例普遍低于5%,质量与效率上为较优的插值模型;内插值精度与数据源精度有关,但与数据源密度关系不大;在给定深度测量极限误差情况下,建议在制定有关数字水深模型标准时,对水深在20 m以内的格网点水深值极限误差可设置为0.4 m。

Accuracy Analysis for Single Beam Echosounder Interpolations

In the paper the accuracy for single beam echosounder interpolations using error propagation law is analyzed.A mathematical model of medium error expression for interpolation of water depth in single beam is established and the results in three experimental zones of a coastal zone in south China is tested.The inverse distance weighting method, shepard method and linear interpolation triangulation method with adaptive Search Radius Method are used to compute the gross error of water depth interpolations in this test.The results show that the ratio of gross errors is less than 5% and the three methods are superior in efficiency and quality.Also,we get that the interpolations' accuracy is related to the precision of data source,but not to the density of data source.In the case of a given depth measurement limit error,we suggest that the limit value of Grid point water depth value should set to be 0.4m in the digital water depth model standards.