Proposed parameters for an automated mapping satellite (Mapsat) system

Landsats-1, -2, and -3, although not defined as mapping satellites, are in fact effectively recording the Earth in a form suitable for presentation as small-scale image maps. These spacecraft have demonstrated the effectiveness of Earth sensing, which must now move from the research to the operational phase. Landsat-D is designed to continue the research effort, but NASA, whose charter precludes operations, has not defined an operational system. An operational Landsat has previously been proposed in technical terms, but this concept was limited to the orthographic (2-dimensional) mode demonstrated by Landsat-1, -2, and -3. Mapping involves topography as well as planimetry, and a satellite compatible with the Landsat that also resolves the 3-dimensional mode of topography is proposed. Such a satellite requires very high stability and pointing accuracy. The current state-of-the-art permits such a satellite to be built and flown in a mode suitable for automated modeling of the Earth's surface in 3- as well as 2-dimensional modes. The satellite would be complementary to or could be combined with the operational Landsat previously proposed and it is suggested it be designated the Automated Mapping Satellite or Mapsat.