Sensors and Sensor Systems

Army, Oct 2004

The Aerial Common Sensor (ACS) offers one representative PEO IEW&S program. It is the Army's airborne ISR system and will replace the current RC-7 airborne reconnaissance low (ARL) and Guardrail common sensor (GRCS) programs. ACS will use the operational and technical legacies of the ARL and GRCS systems, along with technological improvements, to provide a single, effective and supportable multiple intelligence (multi-INT) system for the Army. The ACS will include a full multi-INT capability, including carrying signals intelligence (SIGINT) payloads, electro-optic and infrared sensors, radar payloads and hyperspectral sensors.

The Guardrail Common Sensor (GRCS) is a corps-level airborne SIGINT collection and location system providing tactical commanders near real-time targeting information. There are currently four Guardrail systems fielded worldwide providing support to U.S. Forces Korea, U.S. Army Europe and stateside locations. The program manager for ACS manages the Guardrail program and provides support and modernization for the fielded systems, including the latest Guardrail system 2, which was fielded in 2001.

Key features include integrated communications intelligence and electronic intelligence reporting, enhanced signal classification and recognition, near real-time direction finding, precision emitter location and an advanced integrated aircraft cockpit. Preplanned product improvements include frequency extension, computer-assisted online sensor management, upgraded data links and the capability to exploit a wider range of signals. The GRCS shares technology with the ground-based common sensor, ARL and other joint systems.

Guardrail systems are providing continuous support to the user on a daily basis. PM ACS provides significant modernization to the Guardrail systems in the field to improve system performance, interoperability and transportability. The future will see continued improvements and modernization of the fielded Guardrail systems and the development of the Guardrail information node which will provide a more mobile and capable ground station for the system while also providing interfaces to the tactical exploitation system (TES) and continental U.S. ground stations as part of the DCGS-A Block 1 system.

The Prophet system (three-block acquisition approach: Blocks I, II and III) is the division, brigade combat team (BCT), Stryker brigade combat team (SBCT), and armored cavalry regiment (ACR) principal ground tactical signals intelligence (SIG-INT) and electronic warfare (EW) system that has been designed to support the Army Vision, Transformation and unit of action battlespace. Prophet detects, identifies and locates enemy electronic emitters and provides enhanced situational awareness and actionable 24-hour information for the warfighter throughout the division, ACR and BCT areas of operations. Prophet is made up of a vehicular SIGINT receiver mounted on a Humvee on the battlefield, plus a dismounted manpack SIGINT version for airborne insertion or early entry into the battlespace to support rapid reaction contingency and antiterrorist operations. Prophet Block I is already fielded to the active Army and several Army Reserve and National Guard military intelligence (MI) UAs.

The Prophet is a tactical force multiplier that provides timely support to the Future Force brigade commander's scheme of maneuver. The TSP payload also provides a Future Force capability to the UA and provides timely and critical intelligence and situation awareness to support the brigade commander's fight. These two tactical SIGINT systems are responsive, rapidly deployable, agile, versatile, lethal, survivable and sustainable.

Prophet replaces the intelligence, electronic warfare (IEW) legacy systems and provides a smaller battlefield footprint, reduced airlift requirements, improved emplacement/displacement operations and higher reliability.

The Prophet's modular design allows rapid system upgrades and technology insertion (TI) for a rapid or quick reaction capability (QRC) to support military contingency operations and special operational requirements worldwide. The initial six Prophet Block I systems were rolled out in June 2002, and underwent accelerated production, immediate technology insertion (upgrade) and fielding to provide vital and responsive support to all MI units deployed to support Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF). The Prophet after action reports indicated that the rapidly deployed Prophets provided valuable and timely support to the OEF/OIF military operations.

The Block II/III Prophet is vehiclemounted on the heavy Humvee, with electronic attack (EA), is manportable, and will also provide on-the-move (OTM) lines of bearing and reporting capabilities. This OTM capability is a first for tactical SIGINT operations at the brigade level and will provide on-demand actionable information (or force protection) to the commander.

The multiple-block acquisition approach being followed by the Prophet has fielded 83 Block I systems to the active Army, ACRs and the SBCTs. In March 2003, General Dynamics Decision Systems received a contract to integrate the upgraded Prophet Block I to the Block II/III. The new configuration will also have improved longer-range communications, system netting, increased frequency range, modern emitter collection, plus an integrated electronic attack (jamming) capability to disrupt enemy communications.