photic is a C implementation of the physics-based, satellite-derived bathymetry model as described in (Blake, 2020).
photic is a semi-analytical model for bathymetry, water turbidity and bottom composition; which is primarily based on the physics-based model, HOPE, of (Lee, 1998)(Lee, 1999). Unlike the model of Lee, which was originally designed to use hyperspectral imagery, our model is specifically designed to use multispectral satellite imagery. In particular, we adapt to the greatly decreased spectral resolution by introducing temporal and spatial assumptions on the depth and water turbidity.
The model is described in detail here.
NetCDF developer libraries can be installed via brew with brew install netcdf.
The semi-analytical model at the core of photic uses OpenMP for parallelisation, and can be installed via brew with brew install libomp.
PGPLOT can be installed (on a mac) via macports with port install pgplot, or compiled from source, which can be downloaded from
https://sites.astro.caltech.edu/~tjp/pgplot/
Alternatively, Giza can be used as a drop-in replacement for the ageing PGPLOT library:
https://github.com/danieljprice/giza
photic uses the linenoise library for the repl:
https://github.com/antirez/linenoise
For interactive graphics (on a mac) we need to install XQuartz:
Converting from LANDSAT and Sentinel-2 imagery into a photic-readable gridded file requires gdal (https://gdal.org/), which can be installed via brew with brew install gdal.
All experiments with photic have used the excellent atmospheric correction software, ACOLITE (https://odnature.naturalsciences.be/remsem/software-and-data/acolite):
https://github.com/acolite/acolite
(Blake, 2020) https://arxiv.org/abs/2002.02298
(Lee, 1998) Z. Lee et al, ``Hyperspectral remote sensing for shallow waters. I. A semianalytical model'', \textit{Applied Optics}, vol. 37, no. 27, pp. 6329-6338, 1998
(Lee, 1999) Z. Lee et al, ``Hyperspectral remote sensing for shallow waters: 2. Deriving bottom depths and water properties by optimization'', \textit{Applied Optics}, vol. 38, no. 18, pp. 3831-3843, 1999