中文摘要：

从二维影像中的阴影快速获取建筑物高度是三维数字城市建设中亟待解决的问题。该文提出了一种从Google Earth二维影像获取建筑物高度数据的新方法，利用SketchUp软件模拟光照效果，使三维模型的阴影与二维影像的阴影重合，从而获得建筑物的高度数据，并对如何减小高度数据误差进行了分析。实验结果表明，利用该方法获取的高度数据，可以满足一定的精度要求，而且省时、省力，具有一定的应用价值。

英文摘要：

In this paper,a new method for acquiring the building height from 2D images in Google Eai＇th is proposed, based on analysis of the relations between building shadows in 2D images and its real heights. Firstly,the 2D image in which the buildings located was found and downloaded, and was loaded into the SketchUp software. Secondly, 3D model was created by using SketchUp 3D modeling function,the sun location in the sky was simulated according to the time that 2D images were taken so that the shadows was got by the building 3D model. Thirdly,the solar azimuth angle of the 3D building model was adjusted so as to it is coincident with the solar azimuth angle of 2D images. Lastly,the height of 3D model was adjusted so that the shadow of 3D model and 2D images are overlapped completely, then the height of 3D model was measured and the result was the real building height. In addiction,how to reduce the height error resulted by using this technique was also discussed. Case study indicated that the proposed method in this paper can obtain the correct height of buildings in a satisfied accuracy range.