【作者】 孙学华；

【导师】 卢秀山； 周兴华；

【作者基本信息】 山东科技大学 ， 大地测量学与测量工程， 2011， 硕士

【摘要】 测绘基准是测量工程实施和测量成果的表示基础,现代大地测量技术已经建立起高精度的三维坐标系及其框架,以2+1维的方式表达。前2维属于坐标框架,后1维表示垂直基准。海洋垂直基准在现代海洋测绘基准建设中具有突出的地位,对海洋测深作业和海洋空间信息产品的生产具有越来越重要的理论和现实意义。在海道测量中,一般采用当地深度基准面作为一定海区内深度的参考基准面,我国使用的是理论深度基准面。海图深度基准面用离散验潮站点上深度基准面值表示,通过分区插值扩展到整个海域。它具有明显的区域性,相邻验潮站的深度基准面相对国家高程基准而言存在差异,即深度基准面是一个呈阶梯状的、有缝的基准。本文主要探讨了采用曲面拟合的方法建立一个既能反映海图基准的定义、又能反映海图基准连续性和渐进性变化的无缝海图深度基准面模型。本文用到的拟合方法有Shepard拟合法、移动曲面拟合法、多面函数拟合法和B样条函数曲面拟合法。以黄、渤海为研究海域,对这四种方法的拟合精度进行比较,并提出了每种方法在使用中需注意的问题。采用B样条函数曲面拟合法建立了两个相邻海域的理论深度基准面模型,再用多项式拟合法实现了两个海域的拼接。最后,应用得到的理论深度基准面模型,建立了该基准面相对于参考椭球的偏差模型。更多还原

【Abstract】 Measurement datum is the basis to which the surveys and spatial information are referenced. Nowadays three-dimensional coordinate system and its frame have been established with modern geodetic techniques, and are expressed on 2+1 dimension frame. Thereinto, the first two dimensions says coordinate frame, the third says vertical datum.Marine vertical datum is with prominent position in the modern marine surveying and mapping benchmark construction, and is with more and more important theoretical and realistic significance for hydrographic surveys and marine spatial information product production. Generally, local depth datum is used as reference datum in a sea area for hydrographic surveys. The ordinance datum is lowest normal low water in China. Chart datum is expressed by values of depth datum of discrete tide stations, and is extended to the entire area by the method of partition interpolation. Chart datum has obvious regional. The difference between chart datum of adjacent tide stations and National Height Datum 1985 is different, that depth datum is ladder-like and seaming.Surface fitting is probed to construct a seamless chart datum model which reflects the definition and continuity and gradual change of chart datum, including shepard, mobile surface, hardy function and B-spline function. For the study in the yellow sea and bohai sea waters, fitting precision of four methods is compared, and the problems that should pay attention to in the use are raised. B-spline function is used to construct models of lowest normal low water of two adjacent waters, then two models is spliced by polynomial fitting. Finally, separation model of the fitting datum relativing to the reference ellipsoid is constructed.更多还原