5Urban 3D Surface Information Extraction from Linear Pushbroom Stereo Imagery
5.1Introduction
The launch of the first satellite, SPOT-1, from the Kourou Launch Range in French Guiana on February 21, 1986 on board an Ariane launch vehicle began a new era in imaging systems, for it first employed a linear array sensor and pushbroom scanning techniques (Kiefer 1997). However, it has no along-track capability, which means that the stereo image pair is only constructed by cross-track images. In the 1990s, several American private companies launched their high-resolution satellites, such as EarlyBird (3 m resolution, launched in early 1998 and failed two-way communication) and QuickBird (1 m/4 m) from EarthWatch Inc. and OrbView-1 (1 m/2 m) ...
