|the Self-calibrated Supervised Spectral Shallow-sea Modeler |
Passive optical calibration, bathymetry retrieval, water column correction
and bottom typing of shallow water areas using remote sensing imageries.
Use passive hyperspectral or multispectral satellite images to retrieve both
depth and spectral reflectance of shallow bottom, ready for bottom typing, ahead of any field work.
Leave difficult cases
to semi-analytical methods!
Further to Lyzenga et al's empirical ratio method: water volume reflectance is an important variable.
No need for atmospheric correction.
Uses Jerlov's data for optical calibration.
Just use a X86 or AMD64 laptop
From importing raw data to formating deliverables in one single 4SM executable code.
Uses a bash command line, focussed on productivity.
40 times faster than best ALLUT process on the same CASI image.
|Albert & Mobley's analytical model (2003) is used commercially by EOMAP and PROTEUS. |
For operational purpose, we need a way out:
the simplified shallow water Radiative Transfer Equation.
These BOA models require formal atmospheric correction.
|Following Lyzenga, Maritorena, Jerlov and Kirk, passive optical bathymetry is operational and practical |
"operates" the simplified shallow water RTE.
Being a "ratio method", it works for TOA radiance as well.
4SM only uses the satellite image: no atmospheric correction or field data required.
Yields both retrieved depth and water column corrected spectral radiance ready for bottom typing.
...TOA DN......TOA DN...
This is a TOA simplified RTE: does not require formal atmospheric correction.
No need for field data to retrieve depth in meters
just determine Ki/Kj for wavelengths i and j (Lyzenga), then derive spectral K in m-1 for all visible bands (Kirk).
|Mar 2015: processing of a pan-sharpenned QUICKBIRD image of a GoogleEarth-derived image, Shiraho Reef||read more|
|Sep 2014: generic optical calibration of the Panchromatic band||read more|
|May 2014: 4SM demonstration using CASI data at Heron Island||read more|
|May 2014: ETM over Florida Bay: water types from Coastal4 to OIB||read more|
|Feb 2014: HYPERION at La Parguera Nature Reserve, Puerto Rico||read more|
|Feb 2014: further to Lyzenga's method, and how 4SM adds to it||read more|
|Jan 2014: OLIP at Dry Tortugas National Park, Florida keys, USA, with seatruth LIDAR DTM||read more|
|Dec2013: CASI at Heron Island, GBR, Australia, with seatruth DTM||read more|
Nov2013: the "PANchromatic solution" for shallow water column correction using 4SM
|Nov2013: water volume reflectance and reflectance of the brightest shallow substrates in coral reeef||read more|