Techniques for Computer-Aided Analysis of ERTS-1 Data, Useful in Geologic, Forest and Water Resource Surveys

Forestry, geology, and water resource applications were the focus of this study, which involved the use of compu~er-implemented pattern-recognition techniques to analyze ERTS-l data. The results have proven the value of computer-aided analysis techniques t even in areas of mountainous terrain. Several analysis capabilities have been developed during these ERTS-l investigations. A procedure to rotate, deskew, and geometrically scale the MSS data results in 1:2~,OOO scale printouts that can be directly overlayed on 7 1/2 minute U.S.G.S. topographic maps. Several scales of computerenhanced "false color-infrared" composites of MSS data can be obtained from a digital disp.lay unit, and emphasize the tremendous detail present in the ERTS-l data. A grid can also be superimposed on the 'displayad data to aid in specifying areas of interest, such as avala~che tracks or areas of burned-over timberland. Temnoral overlays of six sets of data have allowed both qualitative and quantitative analysis of changes in the areal extent of the snowpack. Computer-aided analysis of the data allows one to obtain both cover-type maps and tables showing acreage of the various cover types, even for areas having irregular boundaries, such as individual watersheds. Spectral analysis of snow and clouds, water and shadow areas, and forest cover of varying overstory density have revealed several important results. A Laboratory for Applications of Remote Sensing, Purdue Uni versi ty, liest Lafayette, Indiana •• Personnel in',olved in this study were fr-om both the Laboratory fol" Applic~tions of Remote Sensing, Purdue Urdversity and from the InstitU1:e of Arctic and Alpine Research. University of Colorado, Boulder, Colorado. This study was supported by NASA Contract NASS-ZleBO and by NASA Grant NGL 15-005-112.