4SM calibration ETM

Optical calibration, bathymetry, water column correction and bottom typing of shallow marine areas, using passive remote sensing imageries

Calibration of full TM/ETM imageries

and the winner is

18 scenes of Caicos Bank
Miscellaneous images

Caicos Bank: 18 ETM scenes	Caicos Bank: 18 ETM scenes
ETM_009_045_1999-09-20 Caicos cloudy September: K1/K2=0.58 WL[2]=567 nm ==> OIB+0.94 seatruth Z LB	ETM_009_045_2001-01-28 caicos January: K1/K2=0.47 WL[2]=568 nm OIB+0.42 seatruth Z LB
ETM_009_045_2001-07-07 Caicos turbid atmosphere, very bright image, lots of clouds July: K1/K2=0.62 WL[2]=574 nm ==> OII+0.24 seatruth Z LB	ETM_009_045_2002-02-16 February: K1/K2=0.50 WL[2]=566.6 nm ==> OIB+0.53 seatruth Z LB
ETM_009_045_2002-07-10 lots of clouds July: K1/K2=0.46 WL[2]=567 nm ==> OIB+0.36 seatruth Z LB	ETM_009_045_2003-01-18 lots of clouds January: K1/K2=0.446 WL[2]=562 nm ==> OIB+0.18 seatruth Z LB
ETM_009_045_2003-04-24 very nice January: K1/K2=0.446 WL[2]=562 nm ==> OIB+0.18 seatruth Z LB	ETM_009_045_2007-02-14 very nice February: K1/K2=0.540 WL[2]=569 nm ==> OIB+0.80 seatruth Z LB
ETM_009_045_2007-05-05 very high glint, questionable May: K1/K2=0.580 WL[2]=567 nm ==> OIB+0.95 seatruth Z LB	ETM_009_045_2007-12-15 very nice December: K1/K2=0.550 WL[2]=567.4 nm ==> OIB+0.80 seatruth Z LB
ETM_009_045_2007-12-31 very nice December: K1/K2=0.510 WL[2]=571.4 nm ==> OIB+0.71 seatruth Z LB	ETM_009_045_2008-02-17 difficult, blue sky February: K1/K2=0.470 WL[2]=573.3 nm ==> OIB+0.63 seatruth Z LB
ETM_009_045_2008-04-05 difficult, blue sky April: K1/K2=0.470 WL[2]=571.4 nm ==> OIB+0.63 seatruth Z LB	ETM_009_045_2008-04-21 very nice, blue sky April: K1/K2=0.470 WL[2]=562.9 nm ==> OIB+0.32 seatruth Z LB
ETM_009_045_2008-12-17 very cloudy, quite good seatruth December: K1/K2=0.470 WL[2]=569.0 nm ==> OIB+0.45 seatruth Z LB	ETM_009_045_2009-01-02 clear image, quite good seatruth January: K1/K2=0.480 WL[2]=564.9 nm ==> OIB+0.40 seatruth Z LB
ETM_009_045_2009-01-18 cloudy image, quite good seatruth January: K1/K2=0.515 WL[2]=569.8 nm ==> OIB+0.69 seatruth Z LB	TM_009_045_1990-11-22 clear TM image November: K1/K2=0.50 WL[2]=576.3 nm ==> OIB+0.81 seatruth Z LB

Miscellaneous Landsat images	Miscellaneous Landsat images
Alacranes atoll ETM Z BSC	Chinchorro atoll ETM Z BSC
DaviesReef atoll ETM Z BSC	Heron island ETM Z LB
ETM_013_042_2007-12-27 Great Abaco, Bahamas quite nice

And the winner is TM_012_044_1986-02-17

This is Long Island in the Bahamas TM_012_044_1986-02-17: I seem to have lost the image

This provides the most desired proof that 4SM's assumptions are trustworthy.
- WLgreen is set to 577.3 nm here : cWLgreen~=0.6
- WLblue and WLred at mid-wavelength are satisfactory
- Knir at 4.5 m-1 is quite satisfactory, as usual

==>>>>Where it is seen not to be the case, there must be a good reason.
- maybe WLgreen is not set to an appropriate value
- and/or the illumination conditions aren't ideal
- and/or the water body is not as homogeneous as expected
- and/or the brightest bottom type is not present over the whole depth range
That was in 2009:
Thanks to hyperspectral evidence in 2015,
I now think otherwise