Towards earth resources satellites: The american erts and skylab programs

Abstract

Two NASA projects scheduled for 1972 and later deal with remote sensing of earth resources from space: ERTS (Earth Resources Technology Satellite) and Skylab (Apollo Applications Program). This paper firstly examines developments which led to the establishment of the two programs (section 1). It then gives essential technical information concerning the spacecrafts, their orbits and attitudes, the sensors and their coverage capabilities (section 2), the image characteristics, such as scale, resolution, geometry and radiometric properties (section 3) as well as the organization of data handling on the ground and processing considerations and operations (section 4). No attempt is made to make a forecast with respect to applications. However, some indications based on ERTS simulation studies are given in section 1.5, and a table of ground resolutions required for various applications provides the reader with a basis for comparison with expected resolutions.