Radar obsolescence issues are threatening the surveillance efficiency of the U.S. Navy's aircraft carriers and amphibious ships.To tackle the problem, the Navy has tapped industry to upgrade electronics that generate radar signals and to modernize the software that controls the signals.
ITT Gilfillan will provide three upgraded system kits beginning in 2010 under the Radar Obsolescence, Availability Recovery (ROAR) program. Plans call for full-rate production of up to 33 additional systems beginning in 2012. The ROAR program is designed to keep the existing AN/SPS-48 radars in service through 2040.
ROAR is designed to improve fleet readiness by replacing old, tube-based transmitter systems with solid-state electronic equipment and by adding an open-architecture software approach. The Navy's goal is to reduce total cost of ownership, including maintenance, by alleviating the impact of obsolescence in major subassemblies. ITT Gilfillan has promised to reduce unit replacement needs and complexity, and increase meantime between repairs. The changes also should simplify operational training and for the first time give the radar system a built-in-test capability.
The improved systems, designated SPS-48G(V), are to provide long-range 3-D to support target detection and tracking of high-altitude aircraft and missiles, detection and tracking of low-altitude cruise missiles, air battle-management and air intercept control. The Navy has told ITT Gilfillan that the SPS-48G(V) radar must maintain baseline performance characteristics while improving system stability, detection and tracking in clutter environments, reliability, maintainability and availability.
Stability of the solid-state transmitter first stage combined with a new open architecture digital processor should improve the moving target indicator performance and allow better detection and tracking in near shore, littoral environments. The new hardware and software will be designed so waveform and processing improvements can be made to meet future evolving threats.
The Navy introduced the shipboard search radar into the fleet in the mid-1980s as part of the Pentagon's New Threat Upgrade program on carriers and amphibious ships. The Cold War program was designed to improve anti-aircraft capabilities by identifying long-range Soviet Backfire bombers, as well as sea-skimming missiles. The radars were manufactured by ITT Gilfillan, which made minor modernizations to them over the years. Over time, though, the 45 individual systems in the Navy, including two land-based installations, have experienced reduced availability, increased maintenance cost and time, and obsolescence.
Development and procurement of a new system integrating air and surface surveillance with navigation and communications capabilities was beyond the Navy's budget. So the Naval Sea Systems Command contracted with ITT Gilfillan to develop modernization kits to accomplish the command's operational goals for surveillance without busting the budget.
If ROAR is successful, it will reduce the number of replacement units that must be carried aboard ships, and also the overall complexity of the system. Recent advances in very large-scale integration circuit densities, packaging and interconnection methods are meant to accomplish that. The legacy processor functions of scan programmer, target processor, built-in test and interface have been reduced from 77 circuit-card replacement units to fewer than 25 parts.
"We're changing the transmitter technology below decks from tubes to solid state," said Jeffrey Foster, director of Defense Surveillance Radar Systems for ITT Gilfillan. "The Navy funded us to build one of the very first solid-state transmitters in the late 1990s. We transitioned that to production of a U.S. Marine Corps program for a land-based variant of the SPS-48, and we're now transitioning that land-based solid state transmitter into the naval system."
The SPS-48G(V) radar will contain a distributed maintenance and built-in test system to detect and isolate faults and failures within all subsystems of the radar. Test data and results are to be compared with established performance limits and displayed to the maintenance technician in a user-friendly format along with appropriate fault indications, maintenance recommendations and technical data. A long-term history log permits trend analysis and may be used for building a reliability and maintainability database.