Upgraded Early Warning Radars (UEWR) provide detection, tracking, and classification data to the Ballistic Missile Defense System (BMDS). Currently, three UEWRs are deployed by the United States, located at Beale AFB in California, Fylingdales in the United Kingdom, and Thule AFB in Greenland. The Missile Defense Agency is also working to upgrade the Early Warning Radars in Cape Cod, Massachusetts and Clear, Alaska.
UEWRs are nearly identical to Early Warning Radars in technical capabilities, but contain certain software and hardware upgrades that allow the radars to communicate with the Ground-based Midcourse Defense (GMD) system. UEWRs have an upgraded receiver exciter and frequency time standard. In their missile defense role, UEWRs primarily perform target classification and missile tracking to cue other sensors and interceptors.1 UEWRs cannot perform midcourse discrimination, but can begin to classify objects as threatening or nonthreatening, narrowing the range of objects that a higher resolution radar, such as the Sea-based X-band Radar (SBX) would need to observe.2
The sites at Beale AFB and Thule each have two panel configurations while the radar at Fylingdales has a three panel configuration. Each panel of an Early Warning Radar has a 120-degree azimuth. 3 All of the radars are long-range solid-state phased array radars. They have large, fixed-orientation panels facing outward instead of the golf ball-like globes with a rotating radar panel inside like the Sea-based X-band Radar. They operate in the Ultra High Frequency Band, which prevents them from being able to conduct discrimination but allows them to cover a wider area. 4
The UEWR at Beale Air Force Base in California was the first to complete its upgrade in 2005. It participated in the first test of a UEWR for missile defense in 2006, proving not only the capability to track a target, but also the ability to relay information to other GMD components. Because of its proximity to the GMD interceptor site at Vandenberg AFB, the Beale UEWR has been used in every GMD test within its operational range, serving as the demonstration platform for the other UEWR that are farther from testing regions. 5
The Fylingdales EWR received its upgrades and became the site of the second operational UEWR in 2007. [8.Gilmore, FY 2014 Annual Report.] The site originally hosted distinctive golf ball-style mechanical radars, but these were replaced with solid state phased array radars in the late 1980s and early 1990s. 6 Fylingdales is the only UEWR with 360 degree coverage due to its three panel configuration. The Thule AFB UEWR joined the BMDS in 2009. 7 Both Fylingdales and Thule are classified as Ballistic Missile Early Warning Systems (BMEWS), which are slightly larger versions of the PAVE Phased Array Warning System (PAVE PAWS) that are deployed in the United States at sites including Beale. 8 The distinction becomes relevant in the aperture of the radars, with Thule and Fylingdales featuring an 84 foot effective aperture, whereas the Beale site’s is only 73 ft. in diameter.
As of 2014, the Air Force Space Command sustains the UEWRs, as it also performs space situational awareness missions. 9
Plans for upgrading the EWRs at Cape Cod, Massachusetts and Clear, Alaska are progressing and they remain operational while the new software is installed. The Cape Cod site is expected to complete upgrades and become operational in late 2016 to early 2017 and the Clear site in 2017. Both of these sites host radars with PAVE PAWS characteristics, though the Clear site is technically classified as a BMEWS. 10