Fitting data, but poor predictions: Reverberation prediction uncertainty when seabed parameters are derived from reverberation measurements

For many decades, researchers have been developing inverse techniques for estimating seabed parameters from reverberation data, notably scattering strength. Generally, the angular dependence of the scattering kernel is unknown and is either solved for or assumed fixed. In either case, agreement is typically quite good between the measured reverberation and that modeled (by fitting scattering parameters). However, what are the resulting uncertainties in a reverberation prediction if the ocean or geometry changes? The main results of the paper are that (1) these prediction uncertainties are surprisingly large, of order 10 dB at 10 km and thus (2) traditional/current methods for reverberation inversion should be augmented, mitigating the large prediction uncertainties by an additional measurement. Several options for additional measurements are discussed.