When first introduced in the 1970s, supersonic commercial air travel promised Superman-like speed to commercial airlines and the flying public. But as supersonic aircraft traveled at speeds near or above Mach 1, they generated thunderous sonic booms that disturbed people on the ground. For this reason, supersonic travel over land is banned in the United States and other countries.
Until its final run in 2003, the Concorde transported air travelers from London and Paris to New York and Washington, DC, for 27 years in half the time it takes today. Technologies that enable the return of supersonic air travel will remove hours from thousand-mile trips and make long-haul travel more feasible and pleasant for travelers. The ability to travel faster offers benefits to a wealth of industries, including medical, business, shipping, diplomacy, military, and tourism to name just a few.
We at NASA’s Armstrong Flight Research Center have solved this problem not by eliminating the boom but by giving pilots control over it. NASA Armstrong's Real-Time, Interactive Sonic Boom Display can be integrated into any cockpit or flight control room to help pilots place loud booms in specific locations away from populated areas – or prevent them from occurring.
Many factors influence sonic booms: aircraft size, weight, shape and trajectory; weather and atmospheric conditions; and terrain and topography. NASA Armstrong's patented technology integrates and processes vehicle and flight parameters as well as three-dimensional Earth modeling and atmospheric data to predict sonic boom parameters. Prediction data are integrated with a real-time, local-area moving-map display that is capable of displaying the aircraft’s current sonic boom footprint at all times. The processor calculates the sonic boom near a field source based on aircraft flight parameters, then “ray traces” the sonic boom to a ground location, taking into account the near field source, environmental condition data, terrain data, and aircraft information. The processor “signature ages” the ray trace information to obtain a ground boom footprint and calculates the ray trace information to obtain Mach cutoff condition information. A pilot can choose from a menu of pre-programmed maneuvers—such as accelerations, turns, or pushovers—and the predicted sonic boom footprint for that maneuver appears on the map display. This allows pilots to select or modify parameters to either avoid generating a boom or to place it in a specific location.
The technology has been used in Armstrong control rooms and simulators since 2000 and has aided several sonic boom research projects. Numerous aircraft manufacturers are working to design supersonic aircraft that avoid or muffle sonic booms and have stated this technology will enable their future commercial aircraft projects. In addition, the Federal Aviation Administration is expected to require a system of this type to approve flight plans, monitor aircraft in flight, and review flight data to enforce noise regulations.
No other system exists (to our knowledge) to manage sonic booms. Our system is unique in its ability to display in real time the location and intensity of shock waves caused by supersonic aircraft.
More information: http://www.nasa.gov/offices/ipp/centers/dfrc/technology/DRC-008-001-RT-SonicBoom.html