The use of several transducers of different frequencies is now common on board research vessels and fishing vessels, so multifrequency
data are often collected. In order for these data to be combined appropriately, their physical and spatial characteristics
from each frequency should be as similar as possible. We detail the requirements deemed necessary to collect multifrequency
data in an appropriate manner.
Korneliussen, R. J., Diner, N., Ona, E., Berger, L., and Fernandes, P. G. 2008. Proposals for the collection of multifrequency
acoustic data. – ICES Journal of Marine Science, 65: 982–994.