Land evaluation studies with remote sensors in the infrared and radar regions

This paper reviews the literature, especially of the last two years, dealing with remote sensor evaluation of surface and shallow sub-surface characteristics, employing remote sensors in the infrared (1.5p. - 14p.) and radar (0.5 cm - 100 cm) regions. Imaging and non-imaging sensors are examined to assess their current status and possible value in 1) assisting in the mapping of natural plant communities , 2) deriving hydrologic parameters, 3) discriminating among broad land use, crop type, and to a lesser degree, crop state,4) delineating soil and geomorphic units, and 5) estimating soil moisture. Possible applications of these remote sensors in reconnaissance-scale evaluation of natural resources are considered. The paper leans heavily on unpublished and limited-circulation studies sponsored by the National Aeronautics and Space Administration, U.S.A.