ARLINGTON, Va., 6 Jan. 2011. Ocean sensor specialists at the U.S. Defense Advanced Research Projects Agency (DARPA) in Arlington, Va., are taking a project to develop a deep-sea sonar system for advanced anti-submarine warfare to the next level. The project calls for revolutionary advances in extremely deep-operating undersea surveillance systems to protect U.S. Navy aircraft carriers and their support vessels from quiet enemy attack submarines.

DARPA issued a broad agency announcement (DARPA-BAA-11-24) Tuesday for Phase 1b, Phase 2, and Phase 3 of the Deep Sea Operations (DSOP) for deep-ocean surveillance submarine warfare technologies involving sonar and non-acoustic sensors that take advantage of unique signal propagation in the deep ocean.

Phase 1b completes technology risk reduction for the program that began with architecture studies in 2010, and is open to all proposers. Phase 2 will build a scalable sonar system prototype, and Phase 3 will scale the prototype to meet final goals of the program. Phase 3 will emphasize energy, communications, planning tools, and Navy systems.

Proposals should describe a developmental sonar system for large-area coverage, significant fractional hold time, low operational cost, and other deep-sea ASW capabilities. This procurement will favor ambitious system designs that employ deep ocean platform mobility. The best DSOP solutions will use future advances in energy capacity or delivery to extend endurance and improve overall performance.

Navy fixed-site undersea sensor systems today include the Fixed Distributed System (FDS) and the Sound Surveillance System (SOSUS), which are used in ocean choke points in the Caribbean as well as the straits between Greenland, Iceland, Greenland, and the United Kingdom -- commonly referred to as the GIUK Gap.

For the Deep Sea Operations (DSOP) program, DARPA scientists want to use deep-sea areas known as the sound fixing and ranging channel -- also known as the deep sound channel -- that exists at ocean depths below about 3,000 feet where the water is cold, silent, and dense, and where the speed of sound is at its slowest.

Conditions in these areas act as a sound waveguide that enables low-frequency sound waves to travel for thousands of miles. DARPA wants to develop sensors that essentially look upward through this acoustically silent environment to detect the low-frequency sounds of enemy submarines against a quiet background at long ranges.

DARPA experts assume that deep-ocean areas are particularly advantageous for sound navigation and ranging technologies -- sonar for short -- yet will accept non-acoustic solutions, as well.

Goals of the program include the ability to achieve long-range detection and classification of submarines; the means to communicate underwater over long distances; and the ability to manage electrical energy to operate in hostile deep-ocean conditions for long periods.

Technologies developed under the Deep Sea Operations programs must result in sensors that operate near the ocean bottom; take advantage of distributed nodes; that can be configured to a range of operations, and environments; and adapts to the mobility of friendly and enemy submarines and surface warships.

Proposers must have at least a secret facility clearance and the capability to conduct secret-level research.

Companies interested in participating in the Phase 1b, Phase 2, and Phase 3 of the DSOP program should submit proposals no later than 1 July 2011. For questions or concerns contact DARPA by fax at 703-807-9925, by e-mail at DARPA-BAA-11-24@darpa.mil, or by post at DARPA/STO 24, ATTN: DARPA-BAA-11-24, 3701 North Fairfax Drive, Arlington, VA 22203-1714.

More information is online at http://www.fbodaily.com/archive/2011/01-January/06-Jan-2011/FBO-02353502.htm.