Optical calibration, bathymetry, water column correction and bottom typing of shallow marine areas, using passive remote sensing imageries
Busy? 4SM in 10 lines        
4SM illustrated: thematic and geographical



VNC : let's work together live!
4SM errors
4SM conclusions


 
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
 


 
 Investigate
the image

 Prepare
a mask

 Extract
Calibration data

 Optical calibration

  The 4SM
commandline

Equalize
a mosaic

Deglinting

Smart Smoothing

 Normalization
of the data

 Sea truth
Regression

 Water Column
Correction

 Spectral
Bottom Signature

 Bottom typing
Seychelles
Florida
Princess Cays

Heron Island

 Computed Depth

 Contour Map
3D diagram



Deal or NoDeal?

 

  • It shall be seen that an acceptable calibration which yields acceptable results
    • is a fuzzy concept in respect of the many parameters involved
    • even though we are using a simplified radiative transfer model
  • What is important is NOT
    • that a physically exact calibration has been achieved
    • leave that for the big boys at NRL
  • Rather what is important to US
    • is that a coherent set of calibration parameters be assembled
    • so that an acceptable and useful result be produced : DTM and bottom type classification
    • using only the image
  • 4SM offers an integrated set of ergonomic tools to achieve that
    • within a short time frame

Busy? 4SM in 10 lines

Where is the competition?

4SM thematic illustrations : from raw data to final output


 

4SM geographic illustrations : just some of the images processed

 

SPOT XS : in excess of 50 images!

 
Moorea, French Polynesia Bora Bora, French Polynesia
 



Landsat

 
tmnov tutorial
 
Alacranes atoll, Gulf of Mexico Davies reef, Great Barier Reef
Lee Stocking Island, bahamas Gubal Straight, Red Sea
 

 
Sabah, Borneo
 Rangiroa atoll, French Polynesia  Negril, Jamaica Chinchorro, Caribbean Scott Reef, Western Australia
 Herin Island, Great barrier Reef      
 

Ikonos

 
Lee Stocking Island, Bahamas Dubai    
       
 

CASI

 
 
 
     
 
WV2