WorldView 2 image Princess Cays, Eleuthera island, Bahamas
November 11th 2011, 2 m ground resolution
"(c) DigitalGlobe, Inc. All Rights Reserved"
This dataset from Digital Globe under Data Exchange Agreement
courtesy of Gregory MIECZNIK: watch his bathymetry webinar
This page presents the most recent advance of 4SM
as regards the use of the PAN band
along with the MULTI bands of a WV2 image
|September 2012 |
MULTI calibration and seatruth regressions
The good and the bad
The MULTI command line script
Download preliminary depth
|===>||September 2014 |
Command Line MULTI+PAN
Download MULTI+PAN results
|This studycase particularly addresses |
the quest for effective wavelengths
of wide multispectral wavebands
for use with Jerlov's data
The problem of the 575-600 nm range
How does a waveband behave re: operational attenuation coefficient 2K?
So the question is:
how to specify the effective wavelength of multispectral bands in 4SM??
None of the previous attempts succeeded
With the prospect of first class groundtruth by Digital Globe
the following was done:
A beautifull image
very low noise, apart from banding
some faint glint
and adjacency effect
This processing was achieved
within 24 hours
of downloading the image from DG's ftp site.
It is not perfect:
where only bands 1, 2 and 3 exhibit bottom detection, computed depth can easily be underestimated by several meters where bottoms are green.
OIB water type of Jerlov.
Modelling down to ~25 m.
tide height on Nov 11th 2011
is approx 0.50 m above MLLW
on the east coast
The Eleuthera tides on the Exuma Sound side (west coast) of the island are approximately 2 hours behind the tides on the Atlantic side (east coast) of Eleuthera. When rising, ocean tide will be higher on the east coast of Eleuthera then on the west coast.
Adjacency effect at 908 nm
Deglinting removes adjacency effect to satisfaction
|Sept 28th: first calibration |
Sept 28th: first calibration
all wavelengths at mid-wavebands
2K 0.091 0.074 0.142 0.535 0.799 3.500 4.490 8.900
Notice the lousy fit for bands 4 and 5
Please, download TIF image 20 MB
of computed depth in centimeters
16 bits signed from my GoogleDrive
Seatruth by Digital Globe October 3rd 2012
on Sept 28th preliminary work
using UKHO's MBES DTM
DG's depths vs DTM 4SM's depths vs DTM
This image, compiled by Gregory Miecznik,
compares results obtained
|On purpose ||Knowingly |
28 sept 2012: West looks Good
Not knowing where the seatruth DTM is located,
I had managed to get good looking results
at the above sub-window
28 sept 2012: East looks Bad
Sept 28th 2012-DB/princesscaywv/47_3_16_0/8_51/7200_12515/371.657_2745.955/1_1
nice -20 4SM.4.09 -Process -Origin/DigitalGlobe