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

CASI image of Border area at Menton, French Riviera
Work done in 2005


Please refer to Jaubert et al. Marine Ecology Progress Series, Vol 263: 75-82, 2003

Image courtesy of HDI , collected october 2000. This is a 12 bands image, 2891*1479 pixels, pixel resolution 1 meter.
The 4SM licensekey is rated at 716 US$ for this image.

-WL467/508/523/535/544/554/565/574/585/595/644/845 in nanometers

Unfortunately, this dataset lacks bands in the red and green regions of the solar spectrum.

This does not help for an optimal deglinting, and also for calibrating/modeling!

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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
 

A bad mosaic indeed, for excellent data

No visible skyglint or sunglint

Limb brightening dictinctly visible

A bad row in channel_1 shows in blue

Fancy pixels are created upon mosaicking

 

Needs some radiometric improvements

 

Would have needed ILS correction of raw flightlines


 

UL: U8 scaled improved RGB mosaic
LL: U8 deglinted-Smoothed RGB mosaic
UR: Z250 results
LR: normalized bottom reflectance RGB composite

 

UL: Z250 results
LL: U8 deglinted-Smoothed RGB mosaic
UR: image_B of average bottom reflectance
LR: normalized bottom reflectance RGB composite

 

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Zoom 6

a small window shows natural bottom reflectance