Computer enhanced Landsat images for the Ha'il Region of Saudi Arabia

Two Landsat Multispectral Scanner (MSs) digital images depicting the Ha'il Region of Saudi Arabia were subjected to computer corrections and enhancement techniques to highlight geologic, soil, and land cover information applicable to geology, and discovery of new ground water reserves. The main objectives of computer correction and enhancement techniques of Landsat data for these applications are to improve display of image data for analysis and to facilitate evaluation of the multispectral characteristics of the data. These correction and enhancement methods were developed or modified especially for this research.

Correction techniques were used to remove the undesired effects of sun elevation variance, atmospheric haze, striping noise patterns, dropped lines and geometric distortions; thereby rendering "clean" data bases for all bands. Various enhancement techniques were then applied to the data bases individually. Several groups of enhanced images were produced: (1) linear stretched color infrared with l00 percent addback; (2) simulated natural color; (3) hybrid ratio false color; (4) sinusoidal stretch false color; (5) 10l x l01 and 3l x 3l high-pass filter black and white and false color; and (6) horizontal, vertical, and diagonal derivative black and white on Band 5 and Band 7. The methods used for enhancement are discussed and the results compared with respect to their utility in geology, and water resource discovery.