A 1647*1235 Landsat ETM 4 bands image
of Heron Island, Great Barrier Reef, Australia

work done in 2005



 
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
 


 


False color composite, raw data

 


True color composite, raw data
histeq enhancement

 


True color composite, deglinted data

 


image Zstepped

 


image B

 


image LBS
true color composite

 


image BSC

 

 


Optical calibration
Optical water type OII+0.2




Zoom window



over Heron Island

False color composite of raw data
over Heron island at full resolution


image Z stepped

image B


image LBS


image BSC


image WZ


image WR