water column correction, pasive, multispectral, hyperspectral, shallow bathymetry, optical bathymetry,shallow depth, satellite image, marine remote sensing, bottom typing, reflectance, glint correction, coastal management, diffuse attenuation coefficient

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

 casi, landsat, etm, tm, world view 2, wv2, ikonos, hyperion, ali, lee stocking, bahamas, heron, gbr, great barrier reef, caicos, greenland, clipperton, hawaii, jamaica, french polynesia, tuamotu,usvi,buck island reef

Busy? 4SM in 10 lines




This website represents quite a lot of work since 1994,
and it shows, as the older material is often quite outdated


the Self-calibrated Supervised Spectral Shallow-sea Modeler
for shallow water column correction and bottom typing.
Use passive hyper/multispectral remote sensing imagery
to derive both depth and spectral reflectance of shallow bottom.

Optical calibration does not need any field data:
the image itself contains all the information
that is needed for a "ratio method"

 

Busy? 4SM in 10 lines



  Quite an achiement!   And the winner is .....   Quite an achiement!   The value of 4SM  Quite an achiement!       
Let's try SPOT 6 or PLEIADES!
 
About 4SM
4SM technical
4SM offer
4SM study cases
From raw data to bottom typing:
it works
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

Disclaimer                   Your comments are invited            See you on 4SM blog  
Following Lyzenga, Maritorena, and Jerlov, passive optical bathymetry is operational and practical 
The simplified shallow water Radiative Transfer Equation
 ...BOA by Philpot     
 ...BOA by Maritorena et al

"Operating" the simplified shallow water RTE, TOA
 ....TOA in 4SM

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