Author (Your Name)

Taylor Tribble, Colby College

Date of Award


Document Type

Senior Scholars Paper (Colby Access Only)


Colby College. Geology Dept.


Murray F. Campbell

Second Advisor

Thomas Shattuck

Third Advisor

Donald B. Allen


Thermal lnfrared Multispectral (TIMS) images are used to identify lithologic differences on the basis of energy absorption in the mid-infrared wavelength region. In past studies, radiance data collected in flight has been enhanced and then combined to produce a false-color image in which color variation correlates to compositional difference. This study sought to determine what, if any, information could be obtained using 6-channel emissivities calculated from the radiance data. Valuable information is revealed in a set of data collected for the Southern Providence Mountains, California. Channel 4 emissivity values distinguish bedrock from rubble and talus debris due to greater absorption by rock outcrops. Highly correlated (99%) lithologies are distinguished by isolating a wavelength region in which infrared response differs greatest. Isolating channel 3 emissivity values distinguishes basalt from syenite in an area where the two are juxtaposed. In some cases, subtle lithologic differences not apparent in the traditional RGB image are displayed by combining three channels of emissivity data. An area in which felsic dikes crosscut a diorite unit becomes more obvious by combining channel 3,4 and 5 emissivity values in RGB space. These results show that information lies in all six channels of a TIMS data set, and that emissivity images can be used in conjunction with traditional, enhanced RGB images for geologic investigation.


Thermal Infrared Multispectral Images, TIMS, Horse Hills, Hidden Hills


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