Ground-Attack Aircraft Radar to Outmaneuver Overcast Skies

Overcast skies -- such as those at Forward Operating Base Kutschbach in Afghanistan in December -- can cause problems for current radar systems.

Overcast skies -- such as those at Forward Operating Base Kutschbach in Afghanistan in December -- can cause problems for current radar systems. Defense Department

L-3 Communications secures a $2.6 million Pentagon deal to build sensors that use extremely high frequency radio technology to see through clouds.

The Pentagon is building a $2.6 million radar system for armed aircraft that can detect adversaries through cloud cover and dust storms, according to contract filings. 

L-3 Communications has been tapped to develop Video Synthetic Aperture Radar, or ViSAR, for the AC-130 gunship – a close air support aircraft, states a July 9 award notice.

The Defense Advanced Research Projects Agency expects the technology to overcome forces of nature. In certain regions, the weather is overcast half the time, while explosions or incoming rounds during battle can produce dust that obscures typical infrared imaging, DARPA officials said when announcing the search for a contractor last year.

Using extremely high frequency radio, this technology would "deny the enemy the ability to protect themselves by operating in cloudy weather conditions," states a December 2012 solicitation.  "This would also enable U.S. aircraft to use clouds to their advantage by using clouds as a screen while engaging ground targets."

The device would grant troops the same visibility as infrared targeting systems currently provide in clear weather.

L-3 will have to demonstrate the radar can operate within the 231.5-235 GHz frequency -- to provide an adequate frame rate -- and function under geometries characteristic of AC-130 gunship operations. 

During an earlier phase of the program, Northrop Grumman, Raytheon, Nuvotronics and BAE Systems produced some of the underlying research for this application.

The companies worked on extremely high frequency radio band exciters and receivers designed for aircraft, as well as advanced algorithms and a tool to simulate synthetic aperture radar scenes.