Hydrophones
Each hydrophone type has characteristics suited to different tracking needs. Directional hydrophones provide the longest detection ranges and can give an accurate bearing to a transmitter, but their larger, non-hydrodynamic design generally requires the boat to be stopped during use. Towed hydrophones are easier to deploy and can be used from a boat moving at trolling speeds, but they are more susceptible to noise from all directions and do not provide a bearing to the transmitter. For tracking over large surface areas, using both types is often the most effective approach.
DH-4 DIRECTIONAL HYDROPHONE
The DH-4 provides the greatest range and precision in locating transmitters from 30kHz to 100kHz. The parabolic reflector provide 16db of gain over a comparable omnidirectional hydrophone, and yields a calculated DI of nearly 25db, reducing the effect of environmental noise. The DH-4 is the primary hydrophone for manual/active tracking.
Sensitivity: -84 dBV ref 1 uBar (-184dBV ref 1 uPascal).
Beam Width: +/-6 degrees at half power points.
Shaft Length: User supplies mounting shaft. (1 inch PVC)
Output: BNC connector.
Cable: Replaceable 10’ RG-58 C/U.
Links:
Active Tracking Hydrophones Data Sheet
VIDEOS
DH-ROV HYDROPHONE
Length: 100mm
Diameter: 60mm (2” PVC)
Weight: 300 (air) Positive buoyant
Depth: 90m (cable entrance)
Cable: 50m polyurethane jacketed coax BNC terminated
Links:
Active Tracking Hydrophones Data Sheet
Receiver Software
VIDEOS
TH-2 TOWED OMNIDIRECTIONAL HYDROPHONE
The TH-2 provides a simple method for mobile active tracking: its small size and hydrodynamic shape allows for trolling at speeds up to 5 knots, while the long cable length minimizes the affect of engine and prop noise. Eyelets allow attachment of small weights or diving lures to ensure the hydrophone is kept at depth while trolling. This design, though simple, rivals more elaborate and expensive systems in actual field trials.
Sensitivity: -100 dBV ref 1 uBar (-200 dBV ref 1 uPascal)
Beam Width: Omni-directional +/- 2 dB
Output: BNC connector
Cable: 50’ RG316/U
Links:
Active Tracking Hydrophones Data Sheet