中国-中南半岛经济走廊重要节点城市发展状况 遥感分析

针对发展中国家城市经济与环境发展不均衡的问题，以中国-中南半岛经济走廊沿线的7个重要节点城市为例，采用面向对象的随机森林分类方法提取2000—2015年间的土地利用结果。将不透水层空间扩展指数、景观格局指数、区域NO2柱浓度和夜间灯光指数相结合，从城镇化、经济发展和环境变化3个角度对节点城市的发展状况进行研究。结果表明，面向对象随机森林分类方法能够有效提取不透水层，总体精度高于81%，Kappa系数高于0.82；在过去的15年间，各城市以“中心-边缘”或“沿河-内陆”的方向扩张，表现为“先聚集再扩散”“先扩散再聚集”“聚集”的3种扩张模式；城市中金边的夜间灯光指数增速最快，年变化率为1.71；金边、吉隆坡和新加坡为NO2柱浓度呈现负增长，而南宁、万象、河内和曼谷的NO2柱浓度呈现正增长。

Accuracy Assessment of Oblique Aerial Images and Aerial Triangulation Measurement Based on Non metric Digital Camera

Aerial triangulation is a crucial step in three dimensional （3D） modeling.The traditional photogrammetry cannot satisfy the requirement of 3D modeling in current commercial applications.However，recently，the rise of oblique photogrammetry has a good complement to the traditional aerial photogrammetry.In this paper，we proposed a novel approach based on the utilization of oblique aerial images taken by a group of non metric digital cameras.We improved the process of aerial triangulation via a SIFT matching computer vision approach in the first step.Secondly，we analyzed the accuracy of aerial triangulation as well as the sources of several errors which affect the result of the experiment.We found that feature points are dense when artificial structure areas on stereo images are few.The accuracy of the aerial triangulation and oblique aerial images is better than that of aerial images.Resolution of the image is 10 cm，error in plane x and y are in the range of precision，the elevation error is slightly larger in the z value；the precision of plane x and y has improved significantly after increase the number of control points.The sources of errors which affect the result of the experiment are quality of aerophotography，control points setting and accuracy in measurement，personnel operating，method of block adjustment，etc.