Small Business Innovation Research/Small Business Tech Transfer
SR-CATS: A Short-Range Clear Air Turbulence Sensor
Project Description
Clear air turbulence (CAT), often referred to as "air pockets," is attributed to Kelvin-Helmholtz instabilities at altitudes generally above 18,000ft, often in the absence of any visual cues such as clouds, making it difficult to avoid. The vortices produced when atmospheric waves "break" can have diameters of 900-1200ft and tangential velocities of 70-85 ft/sec. CAT is dangerous to aircraft, recently demonstrated by United flight 967 from Washington-Dulles to Los Angeles on July 21, 2010, which encountered severe turbulence and landed in Denver with over 30 injured passengers, 21 requiring a hospital visit. Many other incidents attributed to turbulence have caused injuries or deaths to passengers and crew. Another recently-highlighted hazard is the inadequacy of current airspeed sensors on commercial aircraft. Federal investigators have reported that on at least a dozen recent flights by U.S. jetliners, malfunctioning equipment made it impossible for pilots to know how fast they were flying. Michigan Aerospace Corporation (MAC) proposes the Short-Range Clear Air Turbulence Sensor (SR-CATS) system to detect and measure turbulence within an aircraft length ahead of the aircraft, both as a component of a predictive gust alleviation control system. The integration of the SR-CATS instrument with MAC's full air data solution (airspeed, angle of attack and angle of sideslip), a MAC technology already demonstrated in-flight, will be explored. This proposal will focus on combining these capabilities into a practical solution. MAC's direct-detection UV LIDAR technology uses molecular backscatter and so does not require aerosols, as required by many competing approaches.
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Anticipated Benefits
Clear-air turbulence represents a significant safety hazard as well as passenger-comfort issue for the commercial airline industry. The proposed SR-CATS system has application not only as part of an automatic gust alleviation system, but also as an air data solution that alleviates many problems with current pitot air data. This capability also makes SR-CATS extremely attractive for military aircraft, including fixed and rotary wing, high altitude and high dynamic, manned and unmanned, and even high-altitude airships. Information on winds near aircraft, if downlinked and compiled, will also be of significant value to forecasters, especially from aircraft flying over areas (oceans, etc.) where balloon radiosonde releases and other wind measurements are sparse or non-existent. NOAA and NASA identify the lack of more comprehensive wind-profile data as a major unmet data need for improving the accuracy of weather forecasts. Inadequate atmospheric data (wind speed, direction, temperature and density) also has a significant negative impact along the entire wind energy value chain, including site assessment, operational farms, turbine control, and grid integration. Turbulence and shear are primary contributing factors to higher than expected turbine maintenance and repair costs. Finally, military applications for artillery and munitions delivery, precision airdrop, and aircraft take-off/landing on ships can benefit from SR-CATS technology.
SR-CATS will allow NASA aircraft the benefit of having a clear-air turbulence detection system for predictive gust alleviation control and an optical air data system in one package, suitable for general use by NASA aircraft as well as for flight research concerning clear-air turbulence and scientific studies of atmospheric processes. Ground-based uses include measuring wind speed and direction simultaneously with air temperature and density while also detecting and characterizing shear and turbulence. Potential uses include wind shear detection for space launches, wake vortices detection and characterization for airports, and climate change studies. More »
SR-CATS will allow NASA aircraft the benefit of having a clear-air turbulence detection system for predictive gust alleviation control and an optical air data system in one package, suitable for general use by NASA aircraft as well as for flight research concerning clear-air turbulence and scientific studies of atmospheric processes. Ground-based uses include measuring wind speed and direction simultaneously with air temperature and density while also detecting and characterizing shear and turbulence. Potential uses include wind shear detection for space launches, wake vortices detection and characterization for airports, and climate change studies. More »
Primary U.S. Work Locations and Key Partners
| Organizations Performing Work | Role | Type | Location |
|---|---|---|---|
| Michigan Aerospace Corporation | Lead Organization | Industry | Ann Arbor, Michigan |
Armstrong Flight Research Center
(AFRC)
|
Supporting Organization | NASA Center | Edwards, California |
Primary U.S. Work Locations
-
California
-
Michigan
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This is a historic project that was completed before the creation of TechPort on October 1, 2012. Available data has been included. This record may contain less data than currently active projects.