Guardrail V

The Guardrail V system, the main component of which was the AN/USD-9 Special Purpose Signal Detection system, was designed to support the tactical commander's at the Corps level and below with near real time communications intelligence. Traditionally, the system served a secondary mission to collect intelligence under the peace time tasking (PARPRO) missions. The Guardrail V system, a product improvement program for existing Guardrail systems, used available 1970's technology to produce a reliable, effective system in about 2 years. The system computer processing capability was mainframe oriented, its operation was primarily manual, and the threats were communications intelligence (COMINT) single channel voice and multi-channel. The system has a 3 van Integrated Processing Facility (IPF), 6 Airborne Relay Facilities, and an Auxiliary Ground Equipment (AGE) step van.

Guardrail V employed 1, 2 or 3 remote airborne payloads in stand-off flight tracks to intercept and locate emitters of interest. Remotely controlled VHF/UHF intercept receivers were used to search out tactical threats. VHF direction finding located ground based and airborne communication emitters.

GR-V used a mission configured RU-21H platform. The 3 van IPF supported the mission operation with operator workstations and with a computerized signal data base. Guardrail V was self contained in that it has a full complement of STE and TMDE installed in AN/ASM-189 shelters and had auxiliary vans for spares and transportation of accessories such as the communications antennas used at the IPF.

Guardrail V was a CONUS based COMINT system that was part of the Army worldwide electronic warfare forces. It provided airborne, stand-off collection, and location of tactical communications signals. Redeployment required advance preparations or at least an advanced party to consider the best location and to insure that line of site to the planned mission flight tracks has been properly considered. The system required approximately a 200 foot by 200 foot area for the IPF and a landing strip within range of the planned mission flight tracks.