Using at-sensor radiance and reflectance tasseled cap transforms applied to change detection for the ASTER sensor

The Tasseled Cap Transform (TCT) was originally created for agricultural land investigations. It is a vegetative index commonly used as an indicator of vegetation health and assessing vegetation and land cover change. The nature of the TCT requires linear combinations specific to each sensor. Additionally, the varying units of the reported digital number (DN) require supplementary eigenvectors. TCTs were derived for the at-sensor radiance and at-sensor reflectance and compared using differing change detection application in Mississippi. The Tasseled Cap Soil Brightness Index (SBI) and the Greenness Vegetative Index (GVI) were conducted and evaluated. It was found that the at-sensor radiance based TCT was most useful in a change detection analysis. The desired spectral characteristics were well contrasted while the at-sensor reflectance based TCT tended to be less effective.