scene LC80340432015010LGN00, January 10th 2016
Work done march 2017
GSD 15 m PANsharpened by 4SM
a strong case of Coastal 1 water type down to ~8 m, followed by OII+0.4 at greater depths
The good and the bad:
useful in a time series study case
but very risky as a one-off processing
A good study case for analytical methods, see if they can cope
Ground truth
uses CombinedZ as seatruth DTM
only under all of San Lorenzo Channel and all of Isla Espiritu Santo
 Regression January 10th 2015 vs CombinedZ
|  ZDTM- Z4SM CombinedZ - January 10th 2015 see legend Blue tones: depth is over-estimated Red tones: depth is underestimated |
 This explains that
|  ZDTM=CombinedZ only under all of Channel and all of Isla Espiritu Santo |
Data and Deglinting
a very complex atmospheric and hydrologic situation
 TOA TCC: raw image logarithmic enhancement Note the red discoloured features: these are discoloured waters which do not show up in the NIR or SWIR1 bands (meaning that nothing actually is floating at sea surface) |  BOA TCC deglinted image logarithmic enhancement "deglinting" of lumps of haze and of slight adjacency effect is quite good |
| Glint regressions using NIR there is no hint of sea-surface glint  RMSE values are very high |  a bold move! |
Optical calibration
only under San Lorenzo Channel and and Isla Espiritu Santo
surprinsingly clear-cut, in spite of hydrological complexities
16U data are scaled to allow for comfortable screen display
 Calibration diagram for the whole image for bands Blue, Green, Red and NIR |  Calibration diagram for the whole image for bands Blue, PAN, Red, NIR CoefKPan=1.05 |
What we see is:
| Distinctly stratified waters Water appears to be distinctly clearer deeper than 8 m: a clear view of what I call "stratified waters" |
| Under the BPL assumption..............==> Clearest: the above describes the clearest water over the whole shallow depth range, whatever the location: these shall exhibit correct depths: see areas in light-red_to_light-blue tones in the ZDTM- Z4SM image. Less clear: but the above masks areas where the brightest pixels are in less clear: these shall exhibit under-estimated retrieved depths: see areas in dark red tones in the ZDTM- Z4SM image | ==>.....So now we offer some understanding of the hydrological situation on that day
|
 under GREEN window |  under BLUE window coastal waters all the way down |
 Three windows for calibration for each window, extraction of calibration data is restricted to that window, in order to probe local conditions |  under RED window |
As opposed to
Other scenes exhibit intermediate situations | The bay area, of course, should be described on its own! |
Profiling
from West to East,
and from North to South
You wrote 25/02/17 :
"it is very important to support the theory
that the October 2014 image is the result of the Odile hurricane,
that provoked huge movements of sediments,that disrupted the northern reef...etc,etc"
Hurricane ODILE was on September 10-19th 2014
Z4SM with location of profile Black
 Profile Black october 22nd 2014.............==> 4SM computed depths mostly conform with CombinedZ "the theory that the October 2014 image is the result of the Odile hurricane" |  ==>................Profile Black January 10th 2015 4SM computed depths exhibits two distinct differences with CombinedZ |
January 10th 2015
| January 10th 2015 So
|
| Solution A is impossible because both images are post-ODILE
| Solution B
|
| I am shall download more post-Odile images: It'll be interesting
| Such proeminent discrepancies in retrieved depth would be eliminated by the combining depths process |
Ready for modeling
Retrieved depth see legend | ZDTM=CombinedZ |
 Bottom brightness |  BOA CC WCC normalized BGR color composite:
|
 SAM3 very pale indeed!!! |
