Collecting sidescan sonar data

The figure on the left shows the Klein 2000 sidescan sonar towfish on deck. The towfish is usually towed behind the survey vessel at a known distance, but can be bow mounted for shallow water surveys. This towfish collects data at high and low acoustic frequencies (100 and 500 kHz). Data from higher frequency shows greater detail, but has restricted range. Data from the lower frequency, on the other hand, shows less detail but achieves greater range. GPS position is collected and logged continuously with acoustic data. The sidescan imagery can then be referenced back to a “real-world” position.

On the right, shipboard computer monitors show sidescan sonar data as it is being collected at the two frequencies.