Correcting echo-integration data for transducer motion

When calculating biomass estimates using acoustic echo-integration it is necessary to account for the change in pointing direction of the transducer between transmission and reception. It is shown that a single correction function can be obtained for a wide range of circular transducers, thus removing the need for the correction to be recalculated for each individual transducer. This correction function is also applicable to those transducers whose beam pattern approximates that of a circular transducer.