Bathymetry and water column correction
at SanLorenzoChannel, Baja california
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

Work done july 2018
GSD 15 m

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
I keep digging
until suitable data
become available
500*2000 HICO image of Bahrain, october 21rst 2013
scene iss.2013294.1021.093734.L1B.Bahrain.v04.14946.20131021200925.100m.hico courtesy of OSU
HICO: Hyperspectral Imager for the Coastal Ocean: GSD 100 m
work done march 2016   

see also WV2 at Bahrain


The data

HICO bandset in nanometers for 4SM
WLMin[ 1]=401.2 WL[ 1]=406.9 WLMax[ 1]=412.7   
WLMin[ 2]=412.7 WL[ 2]=418.4 WLMax[ 2]=424.1   
WLMin[ 3]=424.1 WL[ 3]=429.9 WLMax[ 3]=435.6   
WLMin[ 4]=435.6 WL[ 4]=441.3 WLMax[ 4]=447.0   
WLMin[ 5]=447.1 WL[ 5]=452.8 WLMax[ 5]=458.5   
WLMin[ 6]=458.5 WL[ 6]=464.2 WLMax[ 6]=469.9   
WLMin[ 7]=470.0 WL[ 7]=475.7 WLMax[ 7]=481.4    BLUE
WLMin[ 8]=481.4 WL[ 8]=487.1 WLMax[ 8]=492.9   
WLMin[ 9]=492.9 WL[ 9]=498.6 WLMax[ 9]=504.3   
WLMin[10]=504.3 WL[10]=510.0 WLMax[10]=515.8   
WLMin[11]=515.8 WL[11]=521.5 WLMax[11]=527.2   
WLMin[12]=527.2 WL[12]=533.0 WLMax[12]=538.7   
WLMin[13]=538.7 WL[13]=544.4 WLMax[13]=550.1   GREEN
WLMin[14]=550.2 WL[14]=555.9 WLMax[14]=561.6   
WLMin[15]=561.6 WL[15]=567.3 WLMax[15]=573.0   
WLMin[16]=573.1 WL[16]=578.8 WLMax[16]=584.5   
WLMin[17]=584.5 WL[17]=590.2 WLMax[17]=596.0   
WLMin[18]=596.0 WL[18]=601.7 WLMax[18]=607.4   
WLMin[19]=607.4 WL[19]=613.2 WLMax[19]=618.9   
WLMin[20]=618.9 WL[20]=624.6 WLMax[20]=630.3   
WLMin[21]=630.4 WL[21]=636.1 WLMax[21]=641.8   
WLMin[22]=641.8 WL[22]=647.5 WLMax[22]=653.2   RED
WLMin[23]=653.3 WL[23]=659.0 WLMax[23]=664.7   
WLMin[24]=664.7 WL[24]=670.4 WLMax[24]=676.1   
WLMin[25]=676.2 WL[25]=681.9 WLMax[25]=687.6   
WLMin[26]=687.6 WL[26]=693.3 WLMax[26]=699.1   
WLMin[27]=699.1 WL[27]=704.8 WLMax[27]=710.5   PAN
WLMin[28]=836.6 WL[28]=842.3 WLMax[28]=848.0   NIR
Data preparation
  • Binning: HICO's original bands 1_to_52 are binned pairwise into 26 new_channels
  • visible bands are placed in channels 1 to 26 of the working database
  • and NIR band is placed into channel_28 of the working database
  • this is the maximum number of channels in the 4SM command line, even using a full HD screen!
  • Making a PANchromatic: new_channels 10_to_26 are binned into a panchromatic new_channel
  • that's all of the Green-Red region
  • this new_channel is placed in channel_27 of the working database
  • and assigned a wavelength of 705 nm



  • adjacency effect does not dominate the NIR signal

  • by contrast, sea-surface clutter is a significant source of variation of the NIR signal