Telephonics' AN/UPR-4(V) Passive Detection & Reporting System (PDRS) is a passive, multi-channel Automatic Dependent Surveillance-Broadcast (ADS-B), Universal Access Transceiver (UAT) and Mode 5 Level 2 squitter reporting and cueing system. Designed with Department of Defense (DoD), Federal Aviation Administration (FAA) and Eurocontrol regulations in mind, PDRS acts as a receive-only system that provides situational awareness to civil and military aircraft, effectively eliminating radio frequency interrogation transmissions in the airspace. It is deployable in shipboard and airborne environments (fixed- and rotary-wing aircraft) and has been fielded on ground-based radar installations and mobile radar sites. The system's receiver, processor and tracker are based on the common software and firmware of our AN/UPX-44A IFF interrogator.