1. Thermal Emission Imaging System Atmospheric Correction
Colin Ho
ASU Mars Space Flight Facility
Mentor: Phil Christensen

2. Overview
Full atmospheric correction of Thermal Emission Imaging System IR stamps would provide a valuable source of spectral data that can be used for determining the Martian surface composition at a high resolution (100m/pixel)
THEMIS visible stamp and TES mineral map resolution comparison
image from JMARS

3. Objective
To determine if atmospherically correcting Thermal Emission Imaging System (THEMIS) IR spectra using Thermal Emission Spectrometer (TES) data as a basis provides useful data
Assumptions
TES data is pure surface emissivity
General atmospheric composition has little shift over time

4. Method Selecting an area Acquiring data Processing data
Data access tools
TES – vanilla
THEMIS - THMPROC
Processing data
Programming tool
davinci
Using scripts such as i2i (Christensen)
TES pixel outlined upon THEMIS stamp with MOLA in background
Image from JMARS

5. Test Case Raw data comparison After processing using i2i
Area of 44 to 44.25E, 2.75 to 3N used (day IR)
Raw data comparison
After processing using i2i

6. Test Case Results
The derived atmospheric emissivity correlated to the expected atmospheric spectral dust emissivity
Atmospheric dust emissivity
(Smith, Bandfield, Christensen, 2000)
Atmospheric emissivity derived from the difference between TES and THEMIS

7. Analysis
In the initial test case, the results were found to be suitable for atmospheric correction purposes
Plans for future improvement
Using a larger temporal and spatial spread of data
Applying multiple methods of determining emissivity difference
Automating data retrieval, and processing

8. Acknowledgments
Mentor Philip Christensen Special Thanks Kim Murray

9. Sources
Smith, Bandfield, Christensen (2000), Separation of atmospheric and surface spectral features in Mars Global Surveyor Thermal Emission Spectrometer (TES) spectra, Journal of Geophysical Research. Vol 105. No E4. Pages
Bandfield (2002), Global mineral distributions on Mars, Journal of Geophysical Research, /2001JE
Mars Global Data,
THMPROC,
davinci – Main Page , “
Arizona Space Grant Consortium logos ,