This study aims to assess and to evaluate band ratios, brovey and HSV (Hue-Saturation-Value) techniques for discrimination and mapping the basement rock units exposed at Wadi Bulghah area, Saudi Arabia using multispec...This study aims to assess and to evaluate band ratios, brovey and HSV (Hue-Saturation-Value) techniques for discrimination and mapping the basement rock units exposed at Wadi Bulghah area, Saudi Arabia using multispectral Landsat ETM+ and SPOT-5 panchromatic data.?FieldSpec instrument is utilized to collect the spectral data of diorite, marble, gossan and volcanics, the main rock units exposed at the study area. Spectral profile of diorite exhibits very distinguished absorption features around 2.20 μm and 2.35 μm wavelength regions. These absorption features lead to lowering the band ratio values within the band-7 wavelength region. Diorite intrusions appear to have grey and dark grey image signatures on 7/3 and 7/2 band ratio images respectively. On the false color composite ratio image (7/3:R;7/2:G and 5/2:B), diorite, marble, gossan and volcanics have very dark brown, dark blue, white and yellowish brown image signatures respectively. Image fusion between previously mentioned FCC ratio image and high spatial resolution (5 meters) SPOT-5 panchromatic image is carried out by using brovey and HSV transformation methods. Visual and statistical assessment methods prove that HSV fused image yields best image interpretability results rather than brovey image. It improves the spatial resolution of the original FCC ratios image with acceptable spectral preservation.展开更多
The investigated area in this paper is located on the northern mountain in Guangzhou City.It is characterized by high relief and inaccessibility.Multispectral and pan Images of SPOT5 were used as the remote sensing da...The investigated area in this paper is located on the northern mountain in Guangzhou City.It is characterized by high relief and inaccessibility.Multispectral and pan Images of SPOT5 were used as the remote sensing data source,and high-pass filtering(HPF),Brovery transform(BT),intensity-hue-saturation(IHS),principal component analysis(PCA) and the modified IHS(MIHS) methods were adopted for image fusion.Here,a comparison has been made between the entire fused images and the original multispectral images.Subjective evaluation and objective evaluation(entropy,average gradient,correlation coefficient,distribution of gray) have been adopted to assess the quality of the fused images.Also regional geological survey has been taken to find the interpretation veracity.Results show that the MIHS is the best image fusion method for geological hazards interpretation,and the fused image can provide abundant textural and spectral information for easy interpretation of such geological hazards as collapse,landslip,and debris flow.展开更多
文摘This study aims to assess and to evaluate band ratios, brovey and HSV (Hue-Saturation-Value) techniques for discrimination and mapping the basement rock units exposed at Wadi Bulghah area, Saudi Arabia using multispectral Landsat ETM+ and SPOT-5 panchromatic data.?FieldSpec instrument is utilized to collect the spectral data of diorite, marble, gossan and volcanics, the main rock units exposed at the study area. Spectral profile of diorite exhibits very distinguished absorption features around 2.20 μm and 2.35 μm wavelength regions. These absorption features lead to lowering the band ratio values within the band-7 wavelength region. Diorite intrusions appear to have grey and dark grey image signatures on 7/3 and 7/2 band ratio images respectively. On the false color composite ratio image (7/3:R;7/2:G and 5/2:B), diorite, marble, gossan and volcanics have very dark brown, dark blue, white and yellowish brown image signatures respectively. Image fusion between previously mentioned FCC ratio image and high spatial resolution (5 meters) SPOT-5 panchromatic image is carried out by using brovey and HSV transformation methods. Visual and statistical assessment methods prove that HSV fused image yields best image interpretability results rather than brovey image. It improves the spatial resolution of the original FCC ratios image with acceptable spectral preservation.
基金Supported by the National Natural Science Foundation of China (Grant No.40471106)"985" Project of GIS and Remote Sensing for Geo-science of the Ministry of Education of China
文摘The investigated area in this paper is located on the northern mountain in Guangzhou City.It is characterized by high relief and inaccessibility.Multispectral and pan Images of SPOT5 were used as the remote sensing data source,and high-pass filtering(HPF),Brovery transform(BT),intensity-hue-saturation(IHS),principal component analysis(PCA) and the modified IHS(MIHS) methods were adopted for image fusion.Here,a comparison has been made between the entire fused images and the original multispectral images.Subjective evaluation and objective evaluation(entropy,average gradient,correlation coefficient,distribution of gray) have been adopted to assess the quality of the fused images.Also regional geological survey has been taken to find the interpretation veracity.Results show that the MIHS is the best image fusion method for geological hazards interpretation,and the fused image can provide abundant textural and spectral information for easy interpretation of such geological hazards as collapse,landslip,and debris flow.
