Avionics, October 15, 2017 – Military Visibility Requirements Driving Next Wave of EFVS Innovation
Nearly a quarter of all military aircraft crashes and 44% of aviation fatalities since combat operations began in 2002 in Afghanistan and Iraq were caused by degraded visual environments (DVEs), such as brownout, smoke, sand, snow, rain, night and fog conditions, according to statistics from the U.S. Army Combat Readiness Center. DVE occurs when aircrews experience low or zero visibility during takeoff, normal flight and landing.
“These environments restrict both commercial and military operations,” said Greg Cox, corporate VP of the communication, navigation, surveillance/air traffic management business area for Sierra Nevada Corp.
Sierra Nevada has spent more than a decade testing different EFVS sensor combinations, both on the ground and in flight. Key to solving the DVE problem using EFVS technologies, said Cox, is understanding the environmental conditions that need to be mitigated, the mission or flight profile and the obstacles requiring detection and display.
“No single sensor is capable of mitigating all forms of DVE,” said Cox. “Each sensor’s performance is a trade-off between obscurant penetration and image resolution. A truly successful EFVS sensor package will include multiple sensors, each optimized for the environment and the segment of the flight profile they perform the best in, and then fused in real time to provide the aircrews and flight computer with the required imagery and data to enable successful operations.”
Sierra Nevada said it uses a multi-sensor suite fused in real-time with terrain, imagery and obstacle data that is then integrated with symbology and command guidance to restore the visual cues for all modes of flight, in both natural and induced DVE. The company is exploring the strengths and limitations of two-dimensional and three-dimensional sensors and their application in multi-sensor fusing environments.
“Our primary sensor is a 94 GHz millimeter wave radar, which was specifically designed and optimized for mitigating DVE in aircraft. We have also tested and fused multiple light detecting and ranging (lidar) sensors and long-wave infrared (LWIR) cameras,” said Cox, who emphasized that sensor fusion is key to enabling the integration of dissimilar sensor technologies while flexibly accommodating new sensors as they become available.
“As true DVE systems are fielded, the military will be able to conduct operations without restrictions of dust, fog, snow “ and other environmental hazards, said Cox. “It also reduces the landing minimums for approaches in instrument flight rules conditions.”
Sierra Nevada expects EFVS systems to be standard on commercial aircraft within the next five years.