Multiple-frequency Acoustical Estimation

AbstractRemote estimation of abundances and size distributions of certain classes of marine organisms can, in principle, be made from acoustical scattering measurements at several frequencies. These estimates are obtained by solving an inverse problem involving the acoustical measurements and predicted (or measured) scattering coefficients for the organisms. The quality of acoustical size-abundance estimates depends upon several factors, including the accuracy of the measurements, the functional form and accuracy of the scattering model for the organism, the number and choice of measurement frequencies, and the solution algorithm. This paper describes the theoretical basis for multiple- frequency acoustical estimation and analyzes some of the problems involved in making accurate and precise estimates of size abundances.