Why are high frequencies prefered in sonar technologies?

TL;DR - we use high frequencies because they mean smaller arrays and arrays are expensive. I'll state some assumptions first, they're pretty obvious, but, ought to be set out: 1. read more

Contrary to some of the previous answers sound attenuation increases with frequency, to a first order actually with [math]f^2 [/math] (see The speed and attenuation of sound 2.4.1 for an excellent discussion on this), so, for best range we would like the lowest frequency. read more

In the case of a bat this lowest pitch is generally 5kHz or more, which is 1/4 the frequency of most echo location. 2) The counter case to this is the dolphin, which is quite large and could produce lower sounds. read more

scan sonar. A single object on the seafloor was scanned on the same day, with the same system, by the same operator at four different frequencies. Choosing Side Scan Sonar Frequencies Dual-Frequency Options Allow for Flexibility in Capturing Images By Doug McGowen • Rob Morris Image from 400-kilohertz frequency used to survey Buzzards Bay plane wreck. read more