The Air Force upgrades its missile early warning systems

The Air Force is advancing its initiative to upgrade its Ballistic Missile Early Warning System (BMEWS) and Precision Acquisition of Vehicle Entry Phased Array Warning System (PAVE PAWS) systems for completion next year. The upgrade program will improve tracking and classification, and real-time communication capabilities of the advanced phased array radar systems, according to the Air Force Space Command (AFSPC).

Part of the technological support for the modernization efforts comes from the System Engineering and Sustainment program, which Harris Inc. will work on through a recently awarded $7,776,340 contract modification.

According to the Department of Defense, these operations could include supporting advanced antenna technology, experimenting with wide band versus VHF-band signals, and opto-electronic multispectral surveillance, which would build on the phasing concept of the BMEWS and PAWS arrays.

The Airforce first reached out to industry with plans to upgrade the PAVE PAWS and BMEWS in 2012. Officials from the U.S. Air Force Electronic Systems Center indicated at the time that improvements were expected to involve new technology for the front end and remote aspects of the radar for these systems.

The modernization initiative specifically includes the Upgraded Early Warning Radar (UEWR) program for the BMEWS and PAVE PAWS. The UEWR program integrates updated missile detection software with the Ground-based Midcourse Defense (GMD) sensors to allow improved real-time communication with the GMD system, and for enhanced object tracking and classification, reported the AFSPC.

"Based on our initial assessment at Beale, our radar…successfully operated with the other components in the GMD system and provided intercept-quality tracking and object classification data as planned," said Dave Gulla, director of Early Warning Radar Programs for Raytheon, when the system was first tested in 2006.

It will also transition the radars to operating entirely on UHF-band frequencies, with a detection range of up to 3000 miles, reported the Missile Defense Agency (MDA). The first UPEWR improvements will be implemented in the two systems by next year.

As for the PAVE PAW and BMEW systems themselves, both are ground-based, however the BMEWS detects land-based ballistic missile launches from anywhere in the world and then sends warning and attack-assessment data on the missiles to US STRATCOM, Joint Space Operations Center, and the Missile Warning and Space Control Center to be analyzed. The PAVE PAW system performs the same functions, but for submarine-launched ballistic missiles.

Both systems use the latest phased array radar technology, which unlike with mechanical radars, does not need to be physically moved in order to vary where the signal beam is pointed. This “beam steering” takes place by the millionths of a second, according to the Air Force, and is controlled electronically. The “phase” in phased array refers to the timed cycling between incoming and outgoing signals.

Using different phase timing for different signal-receiving areas of the same antenna system allows tracking and surveillance beams to be maintained simultaneously. This dual capability requires advanced technology, as the beam length for surveillance signals is 3, 5 or 8 milliseconds, while the tracing beam length is .25 to 16 milliseconds, according to the MDA.

The contract modification is funded completely from FY17 operations and maintenance budget and its sensor contributions to these two missile detection systems is expected to be complete by February 2019.