Combat DF Block 0 (AN/SRS-1) was an electronic support, signal acquisition, and direction-finding system that provided at sea commanders with near-real-time indications and warning, situational awareness, and cueing information for targeting systems.
Combat DF greatly improved on existing “Outboard” system technology by providing greater flexibility against a wider range of threat signals and increased reliability at lower cost through use of Commercial Off-The-Shelf workstations. The system incorporated the Automated Digital Acquisition Subsystem upgrade enabling exploitation of unconventional and low-probability-of- intercept signals.
The Block 1 was a Full-Rate Production installed on new construction Wasp (LHD-1) and Arleigh Burke Flight II (DDG-72 and follow-on) class ships was well as back fitted on LHDs and DDG-51s.
In 2000, Combat DF was superseded the Cooperative Outboard Logistics Update (COBLU) Phase 1 system during construction of DDG-51 class destroyers. COBLU provided an even greater level of capability for processing modern signal modulations.