DIDSONTM has many applications.

Enumeration: DIDSON works in rivers and streams with rocky, uneven beds where other acoustic measurement products have been ineffective. DIDSON is generally placed in the water near the bank and looks perpendicular to the flow. Fish are imaged and optionally counted and sized as they pass through the sonar's field of view. When it is important to determine the number of fish around a particular structure, DIDSON can replace sampling nets by periodically counting the number of fish in a specific volume.

Fish Behavior: The near video quality of the image allows observation of fish behavior in turbid water and at night near natural and manmade structures such as turbine intakes, fish screens, and the mouth of trawl nets.

• Links: Gallery/Fisheries Management

DIDSON has been mounted on remotely operated vehicles (ROV), autonomous underwater vehicles (AUV), off the side of boats, and held by divers (DH model). The near video quality of the image allows detailed inspections of underwater structures. The sonar has been used for manipulator feedback in turbid water and has allowed underwater work to continue when the video cameras provided only blank screens.

• Links: Gallery/Underwater Structure Inspection

DIDSON can detect oil droplets or gas bubbles rising in water. This is useful for pipeline inspections. DIDSON can image small particles (1 mm in size) at ranges up to 3 meters and can be used to monitor flow dynamics around objects.

• Links: Gallery/Leak and Flow Detection

Users can easily differentiate between rocky and sandy bottoms, determine rock sizes and density, determine plant sizes and density, and note details such as existence and dimensions of sand waves.

• Links: Gallery/Bottom Typing

DIDSON can be used to help recover lost or discarded objects as well as examine underwater structures. If the search area is small, DIDSON can be used both for the initial search (low frequency mode) and the final identification and recovery (high frequency mode). If the search area is large, it is first covered with a side-scan sonar. A side-scan sonar generates a map with bright marks that indicate where there are large acoustic returns. The operators prioritize the marks, go to the locations, and send down an ROV, AUV, or a diver with a DIDSON to identify if it is a false target or the object of interest.

• Links: Gallery/Search and Evidence Recovery

DIDSON is used on AUVs, ROVs, and held by divers to search hulls and berthing areas. The diver-held version has a mask-mounted display with SVGA resolution. The DIDSON images allow one to inspect hulls and berthing areas for damage, fouling, contraband, and improvised explosive devices in turbid water. Without this technology divers would resort to a search by tactile examination. Divers like the fact that they can identify objects from a stand-off distance that provides greater safety.

• Links: Gallery/Hull and Berth Sweeps

DIDSON works well as a component in a harbor surveillance system. A large low-frequency sonar surveys a large volume of water and alerts the operator to an approaching return that exhibits characteristics of a threat. The operator directs a patrol boat to that location and a DIDSON off the side of the boat is used to identify the target as a diver, delivery vehicle, marine animal, or debris. DIDSON can also be used to monitor an underwater location that needs high security, similar to how video surveillance cameras are used on land.

• Links: Gallery/Underwater Surveillance

DIDSON can be placed on an ROV to aid in navigation, manipulator control, and generally to provide vision for the operator in environments where optical systems are ineffective.  DIDSON can be used on the front of an AUV as a forward-looking sonar for obstacle avoidance and filling the gap not covered by left and right side-looking sonars.

• Links: Gallery/Underwater Vehicle Vision and Control