Title

Ground-Truthing Thermal Infrared Multispectral Scanner Images

 

Date of Award

2000

 

Document Type

seniorscholars

 
 

Department

Colby College. Geology Dept.

 

Advisor(s)

Murray F. Campbell

 

Abstract

TIMS images are useful for differentiating lithologies and identifying lithologic contacts in the Horse Hills/Hidden Hills districts of the Eastern Mojave Scenic Area, San Bernadino County, California The Thermal Infrared Multi-spectral Scanner (TIMS) is a six-channel aircraft-mounted spectrometer that measures mid-infrared spectral radiance between the wavenumbers of 1220 and 820cm2. Three selected channels of TIMS radiance data are used to assign additive amounts of red, green, and blue primary color to each -9 by 9m pixel (scene) in a TIMS false-color RGB image. Photo-interpretation of TIMS RGB radiance images permits remote sensing of the extent of regional lithologies and contacts. In RGB radiance images, correlation between TIMS pixels may be used to compare lithologies. TIMS data over lithologic contacts measure the radiance components of disparate lithologies joining to make a new spectrum. Emissivity is calculated by removing the temperature component from TIMS radiance data. Rocks from selected pixels were collected and analyzed during January 2000. Comparisons between TIMS emissivity and laboratory-based Diffuse Reflectance Infrared Fourier Transform Spectrometry (DRIFTS) data are used to ground-truth TIMS data. TIMS and DRIFTS produce qualitatively different spectra for the rocks analyzed. Photo-interpretation of T1MS images cannot be used to infer specific mineralogical assemblages. TIMS is best used for reconnaissance mapping of lithologic contacts and variability. TIMS' best practical application is planning field-sampling strategies.

 

Keywords

Ground Truthing, Thermal, Infrared, Multi-spectral Scanner