CASI at Gezirat Siyul Reef, Red Sea
image courtesy of HDI. This is a 12 bands
image, 2800 by 5900, pixel size is 1 m
This reef is approx 5 km long. The
4SM License Key is rated at 1408 US$ for this image. -WL410/430/451/470/509/523/538/550/608/850
in nanometers Unfortunately, this
dataset lacks bands in the Red and Green region of the solar
spectrum. This does not help for an optimal
deglinting, and also for calibrating/modeling.
Glint parameters appear
to change in a subtle way from start to end of data collection.
And the mosaic includes oblique viewing which fades out at
some locations.
A very good dataset, anyway, with lots of
photons!
Deglinting
is absolutely necessary here.
Deglinting
is quite efficient over shallower bottoms,
but
does not solve all problems over deeper bottoms.
This
chequered image shows
the
water column corrected image in some squares
and
raw image in other squares.
Water
depth is approx 3 m Calibration
diagram for bands 11,
10, 9, 5
Calibration
is excellent.
Note
that the Soil Line is particularly well defined,
Optical
water type appears to be OI+0.3 of Jerlov's
classification. This makes for very clear waters: modeling is
achieved down to a maximum of 37 meters over very bright
bottoms.
of bands at 470, 550 and 608 nm
Radiances in channel 11 at 608 nm
are badly saturated for some weird reason.
thanks to the sandy island.