Optical calibration, bathymetry, water column correction and bottom typing of shallow marine areas, using passive remote sensing imageries
Bathymetry and water column correction
LANDSAT 8 OLIP 
at Caicos Bank, Bahamas
4018*4149, 30 m pixel size, UTM zone 18, downloaded from USGS
Image courtesy of the U.S. Geological Survey
 
Using the Panchromatic band for water column correction
to derive water depth and spectral bottom signature:

Landsat 8 OLIP bandset used for this work

Purple_1Blue_2Green_3PAN_4Red_5NIR_6 and SWIR1_7

Please refer to Bora Bora and Sanaa
for use of the PANchromatic band for water column correction
 
 
scene LC80090452015011LGN00, Jan 11th  2015.
work done in july 2016

home

DTM seatruth   RMSE=0.93 m
PAN solution used
ZDTM+2m-Z4SM
I can't explain such a tide correction,
as it excedds by large any tide prediction
at Caicos Bank (0.8 m max)

see legend
Histogram of ZDTM+1.75m   and Z4SM
tide correction 1.75 m

Z4SM va ZDTM+1.75m

 
What can cause
 such over-estimation
of retrieved depth
?

 
  • spectral K values appear to be correct
  • I can only suspect the Soil Line model
  • maybe also the PAN model




Data and Deglinting

TOA TCC: raw image
logaritmic enhancement

TOA TCC deglinted image
same logaritmic enhancement

 




Optical calibration, optimized
16U data are scaled to allow for comfortable screen display
 
Calibration diagram
for bands Blue, Green, Red, and NIR
Calibration diagram
for bands Blue, PAN, Red, and NIR




Now ready for Modeling
PAN solution used
Z4SM
TCC BOA water column corrected

Average bottom brightness

SAM mapping

see legend for SAM

 



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