The Japanese Maritime Self-Defence Force (JMSDF) has awarded a follow-on contract to Northrop Grumman to deliver three additional AQS-24A airborne mine hunting systems.

The modification contract follows the previous contract that was initially awarded in October 2011 to Northrop for the supply of first AQS-24A to JMSDF.

Under the contract, the company will also deliver airborne electronics and ground-based support equipment for the JMSDF and also includes some components of the airborne electronics to be built in Japan.

"These additional contracts further strengthen our relationship with the JMSDF."

Northrop Grumman undersea systems business unit vice president Tom Jones said: "These additional contracts further strengthen our relationship with the JMSDF."

All the four AQS-24A systems will be used by the JMSDF for the new Kawasaki Heavy Industries-built Airborne Mine Countermeasure MCH-101 helicopters.

The helicopter-towed airborne Sonar mine countermeasure detection system, AQS-24A is integrated with equipped with high-resolution side-scan sonar to detect, localise and classify underwater mines in real-time at high area coverage rates.

Options for the procurement of additional systems, electronics and support equipment are expected to be announced in 2013 by JMSDF, which would continue until the service reaches its full operational inventory objective.

The laser line scanner equipped onto AQS-24A enables underwater mines identification, as well as other objects of interest.

Simultaneous operation of laser with sonar of the AQS-24A will bridge the capability gap by enhancing area coverage rate, reducing mine clearance timeline and easing unnecessary maintenance cycles.

Northrop had received a contract earlier this year to deliver helicopter-mountable, laser mine detection systems for the JMSDF.

The AQS-24A system and its predecessors, AQS-24 and AQS-14, have been operational with the US Navy since 1985.