Optical calibration, bathymetry, water column correction and bottom typing of shallow marine areas, using passive remote sensing imageries

Landsat ETM and OLI images
of Chinchorro atoll, Gulf of Mexico


Work completely updated in january 2016
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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
 
  • This work incorporates all the recent 4SM improvements
  • I want to process a PAN-sharpened Landsat 8 OLIP image of this scene
 

Bathymetric map (2003)
downloaded/extracted from the Internet


 

4SM retrieved depth,
from ETM image Jan 25th 2000


 
   

 
 
 
Chinchorro ETM 29 march 2000: retrieved depth
  • a tide height of approx ~1.5 m would appear to fit the 29 march 2000 ETM scene
  • the bathymetric map is quite difficult to interpret, while the satellite derived image is easy to understand in comparison