Engineers from the US Naval Research Laboratory (NRL) have restored an abandoned unmanned underwater vehicle (UUV) autonomous mobile periscope system (AMPS) as a test asset to evaluate the capability of the navy's periscope detection and discrimination (PDD) technology.

PDD is a radar interface that identifies the presence of elusive diesel-electric submarines by locating their periscope.

Program Executive Office Integrated Warfare Systems requested an available, flexible asset to detect potential technical issues prior to testing the PDD with a submarine, thereby reducing the risk of programme delays caused by carrying out the tests later in the development cycle.

NRL AN/SPQ-9B radar technical direction agent Dave Cardiel and Naval Air Warfare Center Weapons Division (NAWCWD) Point Mugu test and evaluation manager Kurt Dulka subsequently travelled across the Pacific to investigate the AMPS, which matched their initial testing requirements.

The UUV was located at Naval Undersea Warfare Center (NUWC) Keyport Detachment Pacific, Pearl Harbour.

Cardiel said: “AMPS had not been used for a few years and needed new batteries and some maintenance before we could see a demonstration.

“I saw the potential for reviving it and worked with Keyport to obtain cost estimates for a demonstration.

"I then worked with Kurt and John Cunnick from Naval Surface Warfare Center, Port Hueneme Division (NSWC PHD) to entertain the idea of moving AMPS to California as a navy test asset.”

The AMPS UUV was originally designed in the late '90s to offer realistic training for anti-submarine warfare watch-standers.

It was capable of conducting pre-programmed manoeuvres, either on the surface with an exposed mast or at a submerged depth just below the surface.

The research team has now received approval to use the vehicle for PDD testing with AN/SPY 3, AN/SPQ-9B, and next-generation surface-search radar programmes.

"AMPS had not been used for a few years and needed new batteries and some maintenance before we could see a demonstration."

The AMPS will be deployed either on the east or the west coast for radar testing purposes, without access to a torpedo recovery boat.

NAWCWD Point Mugu researchers have developed a low-cost launch and recovery system from re-assembled targets to address the challenge of deploying and retrieving AMPS at sea. 

The system can be dismantled for easy transportation across the US.

The team has also worked in collaboration with NSWC PHD to research and collect radar cross-section data on the periscope mast in order to ensure that the vehicle depicted the threat in a realistic manner.

Image: A mock-up of the Autonomous Mobile Periscope System is pulled out of the water after initial testing with a custom-built launch. Photo: courtesy of the US Navy.