FORWARD Model

A forward model computes the observations that would result from a known physical state, mapping the geophysical variables onto what an instrument would measure. In ocean acoustics it predicts the received sound field given the sound-speed profile, bathymetry, and source, using parabolic-equation, normal-mode, or ray methods. In satellite retrieval it is the radiative-transfer model giving top-of-atmosphere radiance from surface and atmospheric properties. The forward model is the core of any inversion or data-assimilation scheme: the observation operator that lets a system compare model state against real measurements and adjust the state to fit.