Thermal Infrared Imagery/Differentiating geologic units

Sarah Robinson, U.S. Air Force Academy


A two part lab in which students a) manipulate thermal imagery to look at rock types and b) determine what wavelengths are appropriate for discriminating between rock types. The imagery for this lab consists of a Landsat image and MASTER image of the Lake Mead area east of Las Vegas, NV.


Type and level of course
The lab is used in an introductory remote sensing course taught to Geosciences majors and Space Operations majors.

Geoscience background assumed in this assignment
No Geo knowledge required

GIS/remote sensing skills/background assumed in this assignment

  1. How to make RGB combinations
  2. How to take spectra
  3. Knowledge of TIR wavelengths
  4. Knowledge of the uses of VIS, SWIR and NIR wavelengths
  5. Band Ratios (for vegetation, clay and iron)

Software required for this assignment/activity:
ERDAS Imagine 9.3

Time required for students to complete the assignment:
2-3 hours


GIS/remote sensing techniques students learn in this assignment

  1. The application of Thermal infrared imagery to discriminating rock types.
  2. How materials can appear similar in one part of the EM spectrum, but can be discriminated in other parts.
  3. A "rule of thumb" on when to use different parts of the EM spectrum
  4. VIS/NIR/SWIR should be used to detect Iron, Clay, vegetation and when the discriminating factor is based on minor components
  5. TIR should be used to discriminate when bulk composition is different, but is not good at discriminating based on color or minor components

Other content/concepts goals for this activity

Higher order thinking skills goals for this activity

  1. The ability to choose the appropriate imagery for identifying a surface material.

Description of the activity/assignment

This lab introduces students to Thermal infrared Imagery and then asks them to evaluate which wavelengths (VIS, NIR, SWIR, or TIR) are the best choices to identify and discriminate between geologic materials. The lab focuses on the Geology in the Lake Mead Region east of Las Vegas, NV; the lab uses a Landsat image and a MASTER image of the area. Students get experience with a classic band combination using TIR to identify rock types and with making decisions on which wavelengths to use in identifying surface materials.

Determining whether students have met the goals

Students answer questions throughout the lab and submit them on the Lab Turn in Sheet.
More information about assessment tools and techniques.

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