A time series of Landsat 8 OLIP images
at Nosy Be, Madagascar

work done in may 2020 at 15 m GSD
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

   peer-reviewed and published in 2017    

See March 27th 2018

back to study cases

Calibration over the whole image

bi-dimensional histograms
Full image
All_pixels, Deglinted

bi-dimensional histograms
Full image
Shallow_pixels_only, Deglinted

Calibration diagram for 
Blue, Green, Red and NIR bands
Full image. All_pixels Deglinted


Calibration diagram for 
Blue, PAN, Red and NIR bands
Full image. All_pixels Deglinted
In spite of
very low bottom substrate reflectance,
this turns out to be a fairly clear-cut case,

which exhibits CoefK_1.0,
possibly because of supended particles load
along the waterline:
  • Kblue/Kgreen~=0.63      OIB+0.8
  • this is well verified by the red band:
    • Kblue/Kred~=0.152
    • Kgreen/Kred~=0.242
  • Kblue  =0.120 m-1
  • Kgreen=0.191 m-1
  • Kred    =0.788 m-1
this is not for beginners,
and certainly
not for a 4SM tutorial!
Unfortunately, the PANchromatic band
of PLEIADES sensor
covers most of the Blue band.

As a result,
there is hardly any color separation
over most of the shallow depth range,
as can be seen in plot X1 vs X3.

PAN is not usable.

PAN response

Calibration over the import ROI
accross the whole image from Line_800 to Line_1200
  • Fairly tricky, because the shallow subtrates are so dark.
  • It  is seen below that
    • shallow subtrates range over ~70 DNs from 180 to 250
    • while
    • land subtrates range  over ~320 DNs      from  180 to 500: they are ~5 times brighter than the shallow substrates

That is all we have
to map shallow water depths!!

Lands: mask=248
display of all land pixels

Marine: mask=2
display of all marine pixels

Whole: mask=248 +mask=2
display of all image pixels with mask>1


Calibration over specific ROIs







Run the AutoCalibration

content of zipfile
please, do not use your ancient directory: erase it altogether
  • place costa_toscana_sub.pix in ./data directory (as I have removed it)
  • place all shapefiles in working directory, along with script,  4SM.8.03 executable, and 4sm.calls
  • then run this script to perform the AutoCalibration 
(change all @@       for       )
#acquired geotiff 16 bit (not JPEG2000)
#Line_0 - create the database costa_toscana.pix and mak, then run the AutoCalibrator
#Line_0 - create the database costa_toscana.pix and run the AutoCalibrator
nice -20 ./4SM.8.06 -Process/19_Jan_2018 -Origin/MassimoPerna                                     @@
-DB/costa_toscana_sub/34_3s_5s_0s/5_38/7054_6416/615.975_4794.925                                 @@
-Mis/Italy/Costa_toscana/PLEIADESP/1A/NA/bOA/UTM_32_008/0.002_0.002/03_AUG_2017    @@
-MakePIX/Import                                                         @@
-Import/v/dTM/data*costa_toscana_sub/dbnc_0_0S_5S_0s/R7054_L6416/Origin_615.975_4794.925_0_0/chIn1,5/chOut38,42      @@
-SCL/0070.0/0065.0/0075.0/0060.0/0110.0_SCL                                            @@
-LS/0010000/10000/10000/10000/10000                                                @@
-KK1_2_0.50/Knir4.5/CoefK_1.0/mask_3                                                @@
-deglint/vrbaD/GlintM50/Ext_3300_3600_2800_3200                                            @@
-extract/v/RawBDH/FullBDH/NIRband5/NIRmax5/mBPL2    /mask_3                                    @@
-calibrate/voAi/BdSNpzg/BC_5_4_3_2/BDh_12_13_34                                            @@


Run the Modeling
  • disable the AutoCalibration script:      
    • #nice -20 ./4SM.8.05 -Process/19_Jan_2018 -Origin/MassimoPerna
    • #exit
  • make sure the Modeling script which follow is enabled
  • then run this script to perform the Modeling
(change all @@       for   antislash )

#Line_1 - Run the Modeler............Run the Modeler............
nice -20  ./4SM.8.05 -Process/14_Mar_2018  -Origin/MassimoPerna                    @@
-dB/costa_toscana_sub/34_3s_5s_0s/5_38/7054_6416/615.975_4794.925                @@
-Mis/Italy/Costa_toscana/PLEIADESP/PLEIADESP/NA/bOA/UTM_+32_008/0.0020_0.0020/3_AUG_2017    @@
@WLM/550.0/620.0/680.0/710.0/940.0                                @@
@WLm/430.0/500.0/500.0/590.0/740.0                                @@
@WL/0490.0/560.0/590.0/650.0/840.0                                @@
-SCL/070.0/065.0/075.0/060.0/110.0_SCL                                @@
-LS/010000/10000/10000/10000/10000                                @@
-Lsw/196.5/150.2/097.0/089.4/034.6_Lsw_AutoCal                            @@
-dLsw/-2.5/0-2.0/003.0/006.0/000.0                                @@
-Lw/0027.0/015.0/000.0/000.0/000.0_Lw_AutoCal                            @@
-M/@000001/00002/@0003/@0004/00005_M                                @@
-Lm/0001.0/001.0/001.0/005.0/255.0_Lm                                @@
-LsM/241.0/218.7/208.2/231.2/130.4_LsM_cLM=0.900                        @@
-CP/219.80/175.4/000.0/098.1/000.0_5.00m                            @@
-KK1_2_0.63/Knir4.5/CoefK_0.0/mask_3                                @@
-Z/NA0.00d/N_1/nDR_37_1000_zDTM/mask_3                                @@
-B/tclNe/cNorm2.50/Bmin0/cLM 4 0.9                                @@
-deglint/vrbaD/GlintM50/Ext_3300_3600_2800_3200                            @@
-extract/v/rawBDH/FullBDH/NIRband5/NIRmax5.0/mBPL2/Ext_0001_7054_0010_0400     @@
-extract/v/rawBDH/FullBDH/NIRband5/NIRmax5.0/mBPL2/Ext_0001_7054_0800_1200      @@
-extract/v/rawBDH/FullBDH/NIRband5/NIRmax5.0/mBPL2/Ext_0001_7054_1800_2200      @@
-extract/v/rawBDH/FullBDH/NIRband5/NIRmax5.0/mBPL2/Ext_0001_7054_2800_3200      @@
-extract/v/rawBDH/FullBDH/NIRband5/NIRmax5.0/mBPL2/Ext_0001_7054_3800_4200      @@
@extract/v/rawBDH/FullBDH/NIRband5/NIRmax5.0/mBPL2/Ext_0001_7054_4800_5200    @@
-extract/v/rawBDH/FullBDH/NIRband5/NIRmax5.0/mBPL2/Ext_0001_7054_5800_6200     @@
-calibrate/voAI/BdSNpzg/BC_5_4_2_1/BDh_12_23_34                            @@
-Model/v/Rt1.00/dTM/ZM30/mask_3                                    @@
-Smooth/5/D/smart+    -LL10                                    @@
-TpsV/1/3/Bmin150/RLD4/CK1.001                                    @@

every line in italic may be removed
Depth results are in the following channels:
  • U8_channel_9:    depths coded in decimeters
  • S16_channel_35: depths coded in centimeters

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