Image Processing

All images were processed using Intergraph Corporation ERDAS IMAGINE® 2014 software. Prior to image classification, each Landsat Level 1 data product was stacked into a composite multi-band image file and then converted to at-sensor radiance and top-of-atmosphere (TOA) reflectance; finally, adjacent scenes (Worldwide Reference System 2 [WRS-2] path 14 row 33 and path 14 row 34) were mosaicked to a single image and clipped to the study area extent. The six reflective bands (visible blue, green, and red; near infrared; and two short-wave infrared bands) for each sensor were stacked and used in subsequent processing and analyses (table 2). Radiometric processing reduces scene-to-scene variability due to gain changes between scenes or differences in solar zenith angles, exoatmospheric solar irradiance, and the earth-sun distance resulting from different acquisition dates and times (Chavez, 1988, 1989, 1996; Chander and others, 2009).