AFMC Command News

National Radar Test Facility adds VHF capability to heavyweight turntable

  • Published
  • By Jill Pickett

The 704th Test Group, Detachment 1 of the Arnold Engineering Development Complex has improved the radar cross section (RCS) test capability at the National Radar Test Facility tenfold.

“The VHF addition to our heavyweight turntable allows us to unleash our full RF [radio frequency] spectrum on all possible test articles that can be tested on our RCS range,” said Maj. Nathan Lesman, assistant director of operations for Det 1. “We can now conduct RCS [radar cross section] and antenna pattern measurements down to 60 Mhz on all test article types: both penetrable and non-penetrable.”

Prior to this upgrade, the team could not take any measurements below 600 MHz for test articles mounted on the heavyweight turntable.

Turntable testing allows a test article, including full-size aircraft, to be mounted using large pylons or foam columns and rotated to precisely measure the RCS, or visibility of the test article to radar, at various angles.

Improvements to the turntable have already enabled three test programs to test flyable hardware without having to build custom penetrable test articles and pylon mounting hardware.

Penetrable test articles are generally bespoke pieces of range user test articles that are fabricated with a single mounting point that fits onto the rotator assembly of the Detachment’s large, 128-foot pylon. While most operational versions of the test articles are non-penetrable.

As part of the efforts to add the VHF capability, the Detachment conducted VHF measurements to determine the best placement of the radar system in relation to the turntable to optimize the background and minimize ringdown, or feedback induced on the system. The placement of the radar is one way ringdown can be mitigated.

“It might seem trivial to think that all it took was conducting measurements to enable this capability,” said Lesman. “But, there were significant geometry considerations, as well as signal fidelity issues to work through, as indicated by the optimized backgrounds [or] ringdown work that was completed to make this capability an operational reality.”

The Detachment is continuing to look for ways to improve the capabilities they offer, including efforts to enable RCS and antenna measurements below 60 MHz.

“We are always looking to expand the envelope of what is in the art of possible at our range,” said Lesman. “As the U.S. is always looking to improve the capabilities of our warfighting platforms, so too are we looking to be able to support the ever expanding range of capabilities the U.S. can employ in its collective defense posture.”