Hydrophones
Scanmar has developed hydrophones based on recordings and experience with more than 1000 vessels. For vessels with keel, fishing during difficult conditions, we recommend using two hydrophones, one on each side of the keel. The hydrophones can be mounted in the keel or in trunks that Scanmar have specially made.
We will only mention standard trawl hydrophones that consist of three variations:
- Standard hydrophone
- Standard hydrophone with temperature meter. Under given conditions the temperature at the surface can give a good indication of the temperatures further down in the ocean. By logging over time this can give good estimates for the presence of fish.
- Standard hydrophone with noise meter that measures noise level and frequency. Automatic measurement and registration will give a host of important information:
- Changes in the noise image that can be caused by damage to the propellers
- If the vessel operates with a noise picture that frightens different species of fish at shallow waters so that changes in towing speed etc. must be made
- Location of noise generated by equipment on the vessel
- Noise that disrupts reception of signals from sonar, echo sounder and Catch systems (Scanmar’s new SS4 sensors can easily be programmed to reduce the effect of noise)