Own the Weather: Flying in Degraded Visual Environments

Military aircraft are vulnerable in conditions of degraded visibility due to pilots’ inability to discern obstacles, cables, or other aircraft during flight or while landing. (Photo illustration courtesy DARPA)

Military aircraft are vulnerable in conditions of degraded visibility due to pilots’ inability to discern obstacles, cables, or other aircraft during flight or while landing. (Photo illustration courtesy DARPA)

By Bill Crawford, AMRDEC Public Affairs

Army researchers are going after solutions to help aircraft crews navigate in degraded visual environments, where weather, obscurants or obstacles may prove hazardous and even lethal.

Operations in degraded visual environments, known as DVE, are the primary contributing factor to a vast majority of Army aviation mishaps over the last decade: 80-percent of rotorcraft losses in operations in Iraq and Afghanistan were due to “combat non-hostile or non-combat factors” including DVE, according to U.S. Army Program Executive Office Aviation officials.

At the Aviation and Missile Research, Development and Engineering Center at Redstone Arsenal, Alabama, the Army advances and implements technologies to address DVE safety issues and operational limitations.

“Reduced visibility of potentially varying degree, wherein situational awareness and aircraft control cannot be maintained as comprehensively as they are in normal visual meteorological conditions and can potentially be lost,” said Todd Dellert, an experimental test pilot and Acting Project Director, DVE Mitigation, or DVE-M.

DVE includes darkness, snow, rain, blowing sand, dust, fog, smoke, clouds and flat light conditions, which can hamper aviation operations or create scenarios where aircraft control may be lost.

The DVE-M program hopes to exploit DVE as a tactical advantage and to enable safe operations in all conditions, Dellert said.

The team’s mantra is “Own the Weather,” which aims to expand the capability of commanders to deploy rotorcraft aviation assets when the weather is below condition minimums.

“The AMRDEC Degraded Visual Environment Mitigation Program is oriented toward examining the combinations of technologies required that will give Army rotorcraft pilots the advantage on the battlefield,” Dellert said. “This integrated three-pronged approach to a DVE system solution is aimed at increasing air-crew safety and survivability while also helping to provide them every conceivable tactical and operational advantage.”

Those three critical and interdependent areas are:

  • Aircraft flight control characteristics
  • Aircraft state cueing provided to the pilot
  • Advanced imaging sensor development

According to Dellert, the principle focus of DVE-M is how the sensors will perform in concert with each other as a part of a sensor fusion concept.

The DVE-M program fuses images of multiple sensor technologies such as radar, infrared, and laser detection and ranging, also known as ladar. Each of these sensor technologies provides unique advantages for operating in various types of DVE conditions, Dellert said.

“The millimeter wave radar has the greatest obscurant penetration capability in most DVE conditions; though lower visual resolution than either infrared or ladar,” said Maj. Joe Davis, an experimental test pilot at Aviation Applied Technology Directorate. “Infrared  generally has the best visual resolution at night and in light to medium dust, but has not historically performed well in moisture or extreme dust and does not have the capability of storing images into a data point cloud.”

Ladar has significantly greater resolution than radar and enables a see-and-remember capability by storing returns into a data point cloud, which can be rendered as images to the pilot from any eye-point.

Ladar returns are stored into a data point cloud before to a helicopter enters a landing zone with obscured conditions, Davis said. As the helicopter enters degraded visual conditions, high-resolution stored images are rendered to the pilot from his current eye-point, providing the pilot a virtual high resolution near real-time image.

“Successfully fusing the images of radar, IR, and ladar provides the pilot a more accurate, high-resolution picture of the operational environment in all DVE conditions by exploiting the advantages of each sensor technology and compensating for its weaknesses,” Davis said.

The DVE-M program is led by AMRDEC’s Aviation Development Directorate. The collaborative efforts includes the AMRDEC’s Aviation Applied Technology Directorate and Aeroflightdynamics Directorate, the Army Research Laboratory, the U.S. Army Aeromedical Research Lab and the Communications-Electronics Research Development and Engineering Center’s Intelligence and Information Warfare Directorate and Night Vision and Electronics Sensors Directorate.


This article appears in the January/February 2015 issue of Army Technology Magazine, which focuses on sensors research. The magazine is available as an electronic download, or print publication. The magazine is an authorized, unofficial publication published under Army Regulation 360-1, for all members of the Department of Defense and the general public.

The Aviation and Missile Research, Development and Engineering Center is part of the U.S. Army Research, Development and Engineering Command, which has the mission to develop technology and engineering solutions for America’s Soldiers.

RDECOM is a major subordinate command of the U.S. Army Materiel Command. AMC is the Army’s premier provider of materiel readiness–technology, acquisition support, materiel development, logistics power projection and sustainment–to the total force, across the spectrum of joint military operations. If a Soldier shoots it, drives it, flies it, wears it, eats it or communicates with it, AMC provides it.