An EO1-ALI 6 bands image of Greenland Ice shelf, July 31rst 2008

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EO1-ALI, July 31rst 2008
  • Melting has just started
  • The shallow pond is 2400 m from W to E
  • Water is at most 2 m deep
  • Notice that the snow seems to be mostly dirty
  • The challenge is to try and achieve an optical calibration
    • how clear is the water?
    • what operational wavelengths?

Calibration 6 5 4 3

Calibration 5 4 3 2
Optical calibration
  • in spite of the small size of the pond
    • the calibration is possible
  • again, it confirms the need to offset WL[green] towards longer wavelength (solution C) for Landsat and ALI images
  • an operational WL[green]~=586 nm appears to be convenient under the current illumination and water conditions
  • the water would appear to be quite turbid, loaded with the dust that covers the snow!!!

  • 2K[867 nm]~=3.17 m-1
  • 2K[790 nm]~=2.53 m-1

average bottom brightness
mostly very bright, but not everywhere

computed depth
at most ~2 m


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