航摄像片的基本知识 Basic Knowledge of aerial photos 航摄像片的判读 The Mapping of Relief Map 像片的立体观察 Solid observation of photos 航测资料在水利工程中的应用 Applying data of aerial survey in Irrigation Projects 航测成图的简要过程 The brief process of aerial survey 卫星像片简介 Brief introduction of aerial photos