Thematic mapper data: A new land planning tool

PLANNERS traditionally rely on field observations, aerial photographs, and satellite data to prepare land and water resource inventories. Most satellite studies usually focus on use of the Landsat satellites' multispectral scanner (MSS) as a repetitive monitoring tool ( 4 ). The synoptic view, digital format, and infrared wavelengths of the MSS made these data useful for areawide reconnaissance studies throughout the 1970s. Planners, however, have always sought satellite data with a higher resolution for more accurate land use studies. With this in mind, the National Aeronautics and Space Administration has launched two new satellites, Landsats 4 and 5, that include a thematic mapper (TM) ( 9 ). These advanced satellites offer greater accuracy and resolution needed for more detailed analysis and interpretation than the Landsat MSS. Landsat technology Landsat MSS information is one of the most popular satellite data bases now used. This system, which included Landsats 1, 2, and 3, circled the earth every 18 days at an altitude of about 920 kilometers (570 miles). The satellites recorded reflected radiation in two visible bands (band 1, 0.5-0.6 micrometers, and band 2, 0.6-0.7 micrometers) and two near-infrared wavelengths (band 3, 0.7-0.8 micrometers and …