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the Self-calibrated Supervised Spectral Shallow-sea Modeler

Passive optical calibration, bathymetry retrieval, water column correction
and bottom typing of shallow water areas using remote sensing imageries


Use passive hyperspectral or multispectral satellite images to retrieve both
depth and spectral reflectance of shallow bottom, ready for bottom typing, ahead of any field work


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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
 
Leave difficult cases
to semi-analytical methods!
Further to Lyzenga et al's empirical ratio method: water volume reflectance is an important variable.
No need for atmospheric correction.
Uses Jerlov's data for optical calibration.

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

 

Users of Geomatica, ENVI, Erdas, TNTmips, ERmapper, Ilwis, Idrisi, etc,
 no sweat: I only use open source 

            
Just use a X86 or AMD64 laptop
running Linux
From importing raw data to formating deliverables in one single 4SM executable code.
Uses a bash command line, focussed on productivity.

4SM demonstration:

40 times faster than best ALLUT process on the same CASI image
 
Albert & Mobley's analytical model, 2003, is used commercially by EOMAP and PROTEUS
.... BOA
 
HELP!
For operational purpose, we need a way out: 
the simplified shallow water Radiative Transfer Equation
1989  ...BOA radiance  by Philpot     
1994  ...BOA albedo by Maritorena et al
These BOA models require formal atmospheric correction
Following Lyzenga, Maritorena, Jerlov and Kirk, passive optical bathymetry is operational and practical
 "operates" the simplified shallow water RTE 
Being a "ratio method", it works for TOA radiance as well
4SM only uses the satellite image: no atmospheric correction or field data required
Yields both retrieved depth and water column corrected radiance ready for bottom typing
...TOA DN......TOA DN...
This is a TOA simplified RTE: does not require formal atmospheric correction
  
No need for field data to retrieve depth in meters
just determine Ki/Kj for wavelengths i and j (Lyzenga), then derive spectral K in m-1 for all visible bands

 
Starting in 2009, I got paid good money by the same customer
for several demanding projects using Landsat and WV2

Tanzania, Bahamas, Bahrain, Western Australia, Seychelles, Red Sea, and the UAE
     
   
Breaking news
Mar 2015: processing of a pan-sharpenned QUICKBIRD image and of a GoogleEarth-derived image, Shiraho Reef read more
Sep 2014: generic optical calibration of the Panchromatic band read more
May 2014: 4SM demonstration using CASI data at Heron Island read more
May 2014: ETM over Florida Bay: water types from Coastal4 to OIB read more
Feb 2014: HYPERION at La Parguera Nature Reserve, Puerto Rico                                                           read more
Feb 2014: further to Lyzenga's method, and how 4SM adds to it read more
Jan 2014: OLIP at Dry Tortugas National Park, Florida keys, USA, with seatruth LIDAR DTM read more
Dec2013: CASI at Heron Island, GBR, Australia, with seatruth DTM read more
Nov2013: the "PANchromatic solution" for shallow water column correction using 4SM                  
read more
Nov2013: water volume reflectance and reflectance of the brightest shallow substrates in coral reeef   read more

lyzenga maritorena water column correction multispectral hyperspectral shallow bathymetry retrieval passive optical bathymetry shallow depth retrieval satellite image satellite bathymetry satellite derived bathymetry satellite bathymetry accuracy bathymetry mapping software bathymetric mapping software marine remote sensing bottom typing bottom type classification habitat mapping  reflectance  glint correction  coastal managment  diffuse attenuation coefficient  empirical casi  landsat  etm  tm  world view 2  wv2, ikonos  hyperion  oli quickbird ali panchromatic pansharpened  












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