HR: 1330h
AN: T42B-0302    [PDF]
TI: Wavelet-based Fusion Of Panchromatic ETM+ And Multispectral ASTER Images Covering The Neoproterozoic Allaqi-Heiani Suture,Southeastern Egypt
AU: * Ren, D
EM: rencui@utdallas.edu
AF: Mohamed G. Abdelsalam, Department of Geosciences The University of Texas at Dallas Box 830688 Richardson TX 75083-0688, Richardson, TX 75080 United States
AB: The Allaqi-Heiani Suture is a WNW-ESE trending deformation zone defined by a S-verging fold and thrust belt and is dominated by volcano-sedimentary rocks, dismembered ophiolites, and syn- and post-tectonic granitoids. The Advanced Space-borne Thermal Emission and Reflection Radiometer (ASTER) data covering this area is processed by performing the Optimum Index Factor (OIF) analysis for the purpose of selecting the optimum Red-Green-Blue (RGB) color cpombinations. ASTER data have fourteen bands; 3 in Visible and near infrared (VNIR) with 15 m spatial resolution; 6 Short wave infrared (SWIR) with 30 m spatial resolution, and 5 in the Thermal infrared (TIR) with 90 m spatial resolution. Therefore, the selected RGB color combinations from ASTER data are sometimes have poor spatial resolution. The Enhanced Thematic Mapper Plus (ETM+) panchromatic band with 15 m spatial resolution covering the same area is used to enhance the spatial resolution of ASTER images. The ETM+ panchromatic bands and the multi-speectral RGB color combinations from ASTER data are fused together to incorporate the higher spatial resolution of the ETM+ panchromatic band (high frequency information) and the better spectral characteristics (low frequency) of the ASTER bands. Two- and multi-band wavelet transformations are performed for three newly generated ETM+ panchromatic bands based on three histograms that corresponds to those of the three ASTER bands used in the fusion. Three approximation, low frequency images and numerous exact, high frequency images are obtained each time from the ETM+ panchromatic bands. The low frequency information in the ASTER bands (better spectral information) and the high frequency information in the ETM+ panchromatic band (better spatial resolution) are fused together. Hence, the 3 approximation (low frequency) images obtained from the two-band wavelet or multi-band wavelet for the ETM+ panchromatic band are replaced by the three selected ASTER bands, respectively. Three new bands are generated by performing the inversed wavelet transformation for the approximation images from ASTER bands and the corresponding detailed bands from the ETM+ band are used to generate new RGB color combination images. The results from the two-band wavelet and multi-band wavelet are compared with each other and also with other fusion techniques such as RGB-Hue-Saturation-Intensity (HSI-RGB and Color Normalization Transformation (CNT). Wavelet-based fusion proved to be advantageous in retaining better spectral characteristics of multi-spectral ASTER data and incorporating the better spatial resolution of the panchromatic ETM+ data. geological features which were not obvious in either images or images produced by RGB-HSI-RGB and CNT fusion techniques were revealed more clearly in images generated by wavelet-based fusion.
DE: 0933 Remote sensing
SC: Tectonophysics [T]
MN: 2003 Fall Meeting