Model 980 Active Low-Frequency Towed Sonar (ALOFTS)

The Harris Active Low-Frequency Towed Sonar or ALOFTS provides long, medium and short-range detection, localization, classification and tracking of submarines in blue and littoral water environments.

Detection and tracking are provided for both active and passive operations

ALOFTS combines a proven active acoustic source in a variable depth body with an attached towed array to receive active sonar signals. The towed array also provides a full passive sonar capability. Shipboard processing equipment is implemented with the most modern state-of-the-art COTS processing and telemetry electronics. The system includes a torpedo detection capability for self-defense purposes. Automatic detection and tracking are provided for both active and passive operations, greatly reducing operator workload.

Harris Towed Sonar Performs in Littoral, Shallow Water Environments

The towing and handling system combines the VDS and passive towed array to achieve a single "short scope" tow, which provides rapid response to ship maneuvers and is effective in the littoral, shallow water environment where other towed arrays are ineffective. System features for handling the VDS/towed array during towing operations include remote depth control from the sonar operator's console, automatic depth keeping and automatic bottom avoidance capabilities.

Determine contact bearing without complex triplet or multiple towed arrays

Port/Starboard ambiguity is resolved utilizing a directional transmission scheme, which has been successfully demonstrated at sea in various U.S. Navy tests. This allows unambiguous determination of target bearing without the need for complex triplet or multiple towed arrays.