Spectral signatures

Electromagnetic radiation is changed by the atmosphere, but reflectance (the bulk of satellite imaging for mapping) depends greatly on the spectral signature of the material reflecting the incoming radiation.

Below are some common spectra.

Resources for spectral signatures

Example Use of Specctra: Using TM to map Geology in Utah (http://rst.gsfc.nasa.gov/Sect13/Sect13_4.html) well… that NASA link is broken…so these guys mirrored it (? http://geoinfo.amu.edu.pl/wpk/rst/rst/Sect2/Sect2_1.html)

Let’s poke around in Lexington. Go here, choose the  Landsat Explorer app

  • grass
  • pavement or buildings
  • water (silty vs clear?)
  • pine
  • deciduous (summer vs winter?)
  • pastures (summer vs winter?)
  • bare soil

Then change the time of year! Leaf on? Leaf off?  How about a desert? What do we see there?

Where else are you curious about “multispectral” (multiband) reflectance? Let’s go there!