Aerial Photography and Remote Sensing – Study Outline

thermal IR & hyperspectral

You should be able to:

1. describe the advantages of thermal and hyperspectral imaging

A. thermal imaging

1. every object gives off electromagnet radiation, the dominant “color” (energy per photon or frequency) and total amount of radiation increases as the temperature rises

2. most earth objects give off most of their energy in long wavelength infrared

3. measuring long wave IR allows remote measurement of temperatures

4. the total amount of radiation depends also depends to some degree on the material (its emissivity) so some care is needed in calculating temperature in complex images.

5. the atmosphere also absorbs and scatters some wavelengths of IR adding an additional uncertainty

6. examples

a. sea surface temperature show ocean currents such as the gulf stream, and El Nino/La Nina

b. can show water stress in plants as warmer leaves

c. can see at night for surveillance

B. hyper-spectral imaging

1. measures dozens of different color or wavelength bands to show the details of which colors are absorbed and reflected

2. impossible to visualize on an image but allows detail comparison with known materials to do precise identification of different surface materials, including the minerals in rocks