QUICKBIRD 2 TASSELED CAP TRANSFORM COEFFICIENTS: A COMPARISON OF DERIVATION METHODS

Abstract

As remote sensing sensors and data systems become more complex, the need for a simple, meaningful index becomes essential in applications. It is also a key component to any successful data product distribution to create equivalent outputs when compared to past sensor capabilities. This continuity of data and traditional indices will become more important with the approaching Landsat gap and after the next-generation of the earth observation sensors are placed in orbit. The Tasseled Cap Transform (TCT) is a practical vegetative index and spectral enhancement and has been adapted to other multispectral sensors; most notability, the TM, ETM+ and ASTER. Unfortunately, there have been modifications to the Tasseled Cap derivation presented in literature that have created confusion regarding the transform and the proper orientation of the defined feature space. The TCT coefficients for DigitalGlobe’s QuickBird 2 (QB) sensor were derived using three different techniques, each based on the original description of the Tasseled Cap defined feature space. All three techniques achieved nearly the same results. The method based on the Gram-Schmidt Orthogonalization method was the most useful with the QB sensor. This derivation technique was used to create the final reported set of Tasseled Cap coefficients for the 11-bit, DRA-off QB product.