Tools for quantifying and modelling underwater light environments.
Propagates spectral irradiance through the water column via Beer-Lambert
attenuation, computes PAR, and converts between energy and photon-flux
units. Provides the lux_spectrum S3 class for unit-safe
spectral arithmetic and native format readers for TriOS RAMSES and Ocean
Optics instruments. Optional lightr interoperability preserves native
instrument records until their measurement, scale, calibration, and
resampling policies are explicitly declared. Includes visual ecology
utilities: Govardovskii (2000)
visual-pigment templates, photoreceptor quantum catch,
Vorobyev-Osorio colour discrimination (JND), Secchi depth, and
heuristic horizontal visual-range and object-detection scenarios.