| Objective: | Develop a sense and avoid (SAA) technology suite for collision and obstacle avoidance in reduced visibility conditions and/or to avoid hazardous weather conditions.
| Description: | The Air Vehicles Directorate (AFRL/VA) is currently interested in technologies to enable UAVs to actively operate under instrument meteorological conditions (IMC), in reduced visibility conditions, during night and twilight conditions, and avoid hazardous weather.
Weather Avoidance: Pilots rely upon weather forecasters and observers worldwide to avoid and/or mitigate the effects of hazardous weather on aviation operations on a broad area and individual flight plan basis. Despite the advantages of high-technology, skilled meteorologists, onboard weather radar and human judgment/experience, weather effects are a primary factor in the number and causes of aviation accidents and incidents. Hazards associated with convective weather include thunderstorms with severe turbulence, intense updrafts and downdrafts, lightning, hail, heavy precipitation, icing, wind shear, microbursts, strong low-level winds, and tornadoes. Hazardous and inclement weather has a detrimental impact on Air Force flight operations enroute, in terminal airspace and on the ground. Therefore, reducing the effect of weather hazards and delays by establishing an onboard means for weather avoidance is a primary concern for USAF’s ever-increasing UAV operations.
Operations in IMC: Penetration of thunderstorms carries all of the risks outlined in the paragraph above. In addition to the hazardous effects of weather, there are also mission-related concerns. Many UAVs have an all-weather mission radar capability; thus, an all-weather SAA capability is essential to complement the ability to conduct intelligence, surveillance, and reconnaissance (ISR) in or to simply traverse IMC. For example, customs and border patrol organizations are increasingly relying upon UAVs to help monitor U.S. borders. To sustain these 24/7 operations, flight in IMC and under hazardous conditions will have to be conducted. This can only be realized with UAVs capable of all-weather operations. Likewise, ISR capability must be preserved even in IMC. If carried out in areas or under conditions requiring SAA (e.g., in civil airspace or in high-tempo military airspace), UAVs will experience degraded mission readiness during IMC without an all WX capability. Lack of an all-weather SAA capability will not only impact access to the US National Airspace System (NAS), but also affect the ability to comply with International Civil Aviation Organization (ICAO) rules, and the legal capability to fly due regard.
Problem Statement: The system/method used to avoid weather and conduct SAA in IMC must necessarily be able to distinguish between weather returns and air traffic. The equipment and/or algorithms used must be able to resolve weather returns from potential collision hazards. This situation is made worse during flight in clouds with limited or no visibility. Sensor signal intensity and size of returns may not always be reliable cues for determining if the necessary action is to result in weather avoidance or collision avoidance.
Other benefits of all-weather SAA:
• All-WX airfield operations—taxi, takeoff, landing, single-ship and in formation. UAVs must be able to establish where on the airfield they are, and conduct SAA in the terminal flight area.
• All-WX adjunct to establishing AAR capability
• All-WX UAV formation procedures
| | PHASE I: Investigate new and innovative technologies for SAA that would avoid dangerous weather and/or collision threats under reduced visibility. Demonstrate feasibility through modeling and simulation and component prototyping.
| | | PHASE II: Develop a prototype system and evaluate its performance through simulation and ground and perhaps flight test. Evaluate the system’s producibility and maintainability and demonstrate a degree of commercial viability.
| | DUAL USE COMMERCIALIZATION: Military application: This technology would be applicable to any military UAV that intends to operate in other than daytime and perfect weather conditions. Commercial application: This technology would be applicable to any civilian UAV that intends to operate in other than daytime and perfect weather conditions with potential for manned aircraft as well.
| References: | 1. The Office of the Federal Coordinator for Meteorological Services, “National Aviation Weather Program Strategic Plan,” chapter 2, April 1997.
2. Gloria Kulesa, “Weather and Aviation: How Does Weather Affect the Safety and Operations of Airports and Aviation, and How Does FAA Work to Manage Weather-related Effects?,” The Potential Impacts of Climate Change on Transportation: Workshop Summary and Proceedings, 1-2 October 2002.
3. Department of Homeland Security, “The Secure Border Initiative (SBI),” 2 November 2005.
4. FAA Order 7610.4K, “Special Military Operations,” 19 Feb 04, paragraph 4-7-8 (b); DoD Directive 4540.1, “Use of Airspace by U.S. Military Aircraft and Firings Over the High Seas,” paragraph 5.3.2.1.1, January 13, 1981, certified current as of December 8, 2003.
| | Keywords: | UAV, sense and avoid, SAA, IMC, weather |