Optical calibration, bathymetry, water column correction and bottom typing of shallow marine areas, using passive remote sensing imageries
 
SPOT, ETM and Hyperion in Kiribati, Pacific Ocean
return to 4SM Study Cases
 
please refer to PATTERNS OF CORAL REEF DEVELOPMENT ON TARAWA ATOLL (KIRIBATI)
Paulay & Kerr, Bull Mar Sci 69(3) 1191-1207, 2001

 


 
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
 


HYPERION
A 762*1934 EO1 HYPERION 26 bands image of Tarawa atoll, Kiribati, July 11th 2002
A 393*651 EO1 HYPERION 26 bands image of Tarawa atoll, Kiribati, May 25th 2003


ETM
A 4 bands Landsat ETM image of Marakei atoll, Kiribati, July 11th 2002
A 4 bands Landsat ETM image of Abaiangb atoll, Kiribati, July 11th 2002
A 4 bands Landsat ETM image of Tarawa atoll, Kiribati, July 11th 2002
A 4 bands Landsat ETM image of Maiana atoll, Kiribati, July 11th 2002

SPOT