Research On Corresponding Relationship Between Rock Image Grey Value And Spectra

The spectra of ground object are theoretical basis of remote sensing applications. Rockspectral data obtained by the field test is the spectral reflectance of the rock, but ETM remotesensing image in the visible-infrared bands is the quantization of remote sensor to receive thetotal energy emitted pixel (gray value). So, clear the relations between them is the necessarypremise for image processing and geological interpretation of ETM images using measuringspectrum.This paper takes Chagannur-Beizhan region locating in the north of Xinjiang Hejingcounty Balgunty-Kunges as the research area, ETM image and rocks field and laboratorymeasured spectral date as research objects, similar coefficient clustering analysis method andregressive analysis method as technical means. By the comparison and analysis toward thethree types of date, and according to the results, get to draw a regression model of remotesensing date and field experimental date, as well as field and laboratory experimental date.The contributions of this dissertation are as follows:(1)This paper classified rocks according to their spectral shape by similar coefficientclustering analysis method, and analyzed the spectral characteristics of all kinds of spectrumwhich based on spectral reflectance curve. Ultimately, we concluded that rock spectrumcharacteristic absorption bands in the study area are iron ion spectral band, water band andhydroxyl bands, mainly caused by magnetite, hornblende, chlorite, epidote and other alterationproducts.(2)A comparative analysis summary of field and laboratory measured spectral date, theresult show that: as for the same rock, the shape of spectral curves of field and laboratory arebasically identical, showing the same spectral absorption and reflection characteristics, and thereflectivity of different as the only difference. With the characteristics of the sphericalreflector, solar elevation angle and solar azimuth angle less impact on the rock spectralreflectance.(3) A comparison and analysis on resample field measured date and rock gray spectrumcurve characteristics of the ETM remote sensing image data, the result show that: as forsimilar rock, gray value curve of ETM remote sensing image and resample field measuredspectrum curve show the same trend, have the same absorption or reflection characteristics inthe same band, and exist a certain linear relationship.