Test flights for DARPA’s Video Synthetic Aperture Radar (ViSAR) program have recently completed, demonstrating successful results. Trial runs showcased a new sensor capable of recording video in real time through cloud coverage.
The ViSAR program began back in 2013, with the goal of developing an Extremely High Frequency (EHF) targeting sensor ideal for cloudy skies that can match the efficiency of electro-optical and infrared (EO/IR) sensors in clear conditions. The EHF sensor would be in a moveable gimbal, mounted on differing aerial platforms, and provide full-motion video for engaging moving ground targets.
The program targets four main technical areas: Compact flyable EHF-band exciters and receivers; EHF-band scene simulation; compact flyable EHF-band medium-power amplifier; and advanced algorithms for EHF-band operation.
“The recent flight tests of the ViSAR sensor marked a major program milestone toward our goal, proving that we can take uninterrupted live video of targets on the ground even when flying through or above clouds,” says Bruce Wallace, program manager in DARPA’s Strategic Technology Office.
“The EO/IR sensors on board the test aircraft went blank whenever clouds obscured the view, but the synthetic aperture radar tracked ground objects continuously throughout the flight,” Wallace adds.
A modified DC-3 aircraft carried out the test flights. Ranging from low to medium altitudes, researchers analyzed the results from EO, IR, and ViSAR sensors mounted on standard gimbals.
The device uses a standard gimbal with a synthetic aperture sensor, while maintaining the needed frame rate was key in the design. According to Wallace via DARPA, cloud-penetrating radar used for space or other operational systems exists, but does not carry the above features.
“Refining the ViSAR sensor’s visualization software to provide operators a representation they’re used to seeing is the next step in the program. We don’t want operators in the back of an aircraft to need special radar training to interpret the sensor’s data—we are working to make the visual interface as easy to interpret as existing EO/IR sensor displays,” says Wallace.
After the successful sensor demonstration, the ViSAR program will now “integrate the sensor into an aircraft that includes a complete battle management system, capable of real-time target engagement.”