Marine Laboratories, Techniques and Research News
From Hydro International
JW Fishers, USA, has added a new high-frequency side scan system to their line.
The 1200kHz sonar produces detailed images of even small and soft targets such as old wooden wrecks, areas of scattered debris, or a drowning victim.
The new sonar is available as a single-frequency system or a dual-frequency side scan with two sets of transducers in one towfish.
Putting two sets in one fish provides versatility allowing the operator to switch between frequencies at any time during operation. The lower frequency is capable of scanning long ranges, but with less resolution.
When the 1200kHz was towed over a bicycle that had been disposed of in a waterway (inset), the bike’s frame and wheels were clearly visible, as well as the seat and other features.
The two frequencies available for coupling with the 1200kHz in a dual-frequency system are the 600kHz and the 100kHz.
The 600kHz provides a combination of range and resolution with a maximum scan of 200 feet per side (400 foot swath), yet with the capability of detecting small targets.
The 100kHz has the longest range, up to 2,000 feet per side (4,000 foot swath), making it ideal for scanning large areas when searching for big targets such as downed aircraft or sunken ships.