The main contents are as follows : it discusses and simulates several problems of digital map technique in aviation : including random terrain , mountain simulation , fractal surface generation , by those we can get statistic data of the terrain . we can get the data not on the grid by fractal interpolation surface 具体内容包括以下几个方面：针对数字地图技术，本文讨论并研究了随机地形算法、山峰模拟算法、分形曲面生成算法，通过这些算法可以得到具有不同统计特性的地形数据；使用基于分形插值曲面算法可以得到不在网格点上的地形数据。
Modeling : this thesis develops a method different from traditional techniques that begins with the cylindrical projection of a generic model and its seamless global texture map using multiresolution technique , and then automatically fit the unwrapped cylindrical projected mesh to the texture map with an improved algorithm that based on 2d morphing to specify corresponding feature points ( or lines ) . finally , we propose a formula of inverse cylindrical projection to recompose the deformed mesh , and after the texture mapping a photo - realistic individual facial model is created 采用多分辨率技术构造纹理无缝拼接图，然后把三维网格模型投影到圆柱面上并展开，根据二维图象变形技术中特征点匹配算法的数学思想，将匹配公式进行改进后应用于模型网格点的适配，在作了一定假设后推导出逆向圆柱映射的计算公式，再将适配后的柱面网格映射回去，最后进行纹理映射生成真实感的特定人脸的三维模型。
The disadvantage is that small variations in coastlines such as bays and inlets cannot be resolved . the bay model complements the first by using a very fine grid to resolve those geographic features such as bays and inlets at which storm surge observations are absent and where storm surge information is required as design parameters for coastal structures such as embankments 而港湾风暴潮模式的覆盖范围较小，这模式利用一套非常密集的网格点来计算出例如港湾和河口等地理位置的风暴潮资料以补开阔海岸模式的不足。当建设沿岸工程如堤坝等需要参考港湾和河口的风暴潮资料而又没有这些纪录时，这套模式便派上用场。
In addition , airway winds , which are essentially grid - point wind and temperature data over the south china sea for 15 flight levels between 10 , 000 and 43 , 000 ft , are disseminated to the radar data processing and display system ( rdpds ) of the cad for calculation of the expected arrival time of aircraft at check points 除此之外，气象数据处理系统将飞机航道风的数据传送至民航处的雷达数据处理及显示系统，这些数据是风和温度的网格点值，其水平范围覆盖南海，垂直范围是由10 , 000至43 , 000尺之间的15个飞行高度；以上资料可用来计算航机抵达各定位点的时间。
Second , a parallel adaptive ray - casting algorithm for graphic rendering of cfi is developed . in the computational model of cfi , the line - of - sight integration is difficult to obtain for 3d complicated flow field , because curvilinear grids , multizone curvilinear grids , and other irregular grids that are commonly used in computational fluid dynamics ( cfd ) present interesting challenges , such as the complex shapes of cell regions defined by grid points ; the wide variation in the sizes of cells in different regions of the grid ; and the intersecting or overlapping nature of multi - grids . the parallel adaptive ray - casting algorithm is extremely efficient to solve these problems 并行自适应光线投射法继承了光线投射法适合于任何形式网格的优点；光线与计算网格的交点自适应地反映了原来网格点物理量的分布，能够与数值计算的精度保持一致；图像平面的自适应算法使我们不必从每一个像素发出射线，既提高了光线投射法的计算效率，同时又保证重采样后激波这样的高频信息不会损失；将并行处理技术引入计算光学流动图像生成过程，解决了大规模数值模拟结果的处理对计算速度和内存容量的需求。
In the third section , the emphasis was put on evaluation of the gradual effects of climate change in future 50 years . all the three sections drew an outline of global climate change affecting the whiter wheat production at present and in future in the studied region . in the third section , the gradual climate change scenarios considering both climate and its variability in future 50 years ( i . e . , 2010 , 2030 and 2050 ) were generated , using outputs of the giss transient run and the baseline , adopting the same method described in the second section mentioned above 第3部分，选择gisstransientrun (气候渐变模型)的有关网格点值，采用上述第2部分同样的方法，生成了研究区域未来50年内(即2010年、 2030年和2050年)兼顾气候及其变率变化的气候渐变情景，并结合ceres - wheat的模拟结果，分析了气候及其变率变化对研究区域冬小麦生产的阶段性影响，并应用gis软件，对各代表性样点的有关模拟结果进行了图像显示。
