A 894*1086 Landsat ETM 4 bands image of
Scott Reef, Great Barrier Reef, Australia

image courtesy of Serge Andrefouet, USF

work done in 2002, updated 2005

4SM licensekey is 97 US$ for this image

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1 - NO NEED for field data, nor for atmospheric correction
2 - this is demonstrated in this website, using a variety of hyper/multi spectral data
 
Requirements are
1 - homogeneous water body and atmosphere
2 - some coverage of optically deep water
3 - some coverage of dry land
 
Problems are
1 - the precision on estimated depth is found wanting, because the noise-equivalent change in radiance  of accessible data is too high for shallow water column correction work 
2 - radiance data should be preprocessed by the provider at level 1 in order to improve S/N ratio
3 - exponential decay: the deeper/darker the bottom, the poorer the performances
 
So
I keep digging
until suitable data
become available
 

see 3D diagram by CSIRO 1999
see also IMOS
habitats by CSIRO
Not an easy calibration:

-there is hardly any dryland

-very dark bottoms inside the deep lagoons are dubious:
the alternative would require modeling a stratified water structure with less clear waters at depth

 

Seringapatam atoll
North Scott reef
South Scott reef
Seringapatam atoll
North Scott reef
South Scott reef

Optical water type OII
for wavelengths 477, 577, 661 and 835 nm
Not an easy calibration:

  • there is hardly any dryland

  • very dark bottoms inside the deep lagoons at North Scott are dubious: the alternative would require modeling a stratified water structure with less clear waters at depth

  • but this of course cannot apply to the South Scott Reef

    needs seatruth

Glint regression

 









Seringapatam atoll









Seringapatam atoll