Sonic Boom Measurement Techniques
An Armstrong research effort is focused on demonstrating and validating various innovative methods for recording and measuring sonic booms. Activities range from collecting data above and below sonic booms
via a sophisticated array of microphones to gathering information from remote sensors and WiFi-controlled microphones strategically placed within communities. The team is advancing NASA's understanding of how individuals and communities react to low-noise sonic booms.
Work to date: The team supported the Farfield Investigation of No Boom Threshold (FaINT) project and also designed and completed the Waveforms and Sonic boom Perception and Response (WSPR) project.
For the WSPR effort, the team installed WiFi-controlled microphones within a 1- to 2-square-mile area on Edwards Air Force Base, then recorded not only the low-noise sonic booms but also public reaction to them using written and Web-based questionnaires and a smart phone app.
Looking ahead: Data from the recent community response pilot study will be valuable for future public perception studies in communities that do not normally experience sonic booms.
Partners: Participants in the WSPR project included NASA's Langley Research Center; Wyle; Gulfstream Aerospace Corp.; Fidell Associates, Inc.; Pennsylvania State University (PSU); and Tetra Tech. Participants in the FaINT project included Langley, The Boeing Company, Cessna Aircraft Company, Gulfstream, PSU, Wyle, Dassault Aviation, and the Japan Aerospace Exploration Agency (JAXA).
Advanced measurement techniques:
The FaINT and WSPR projects furthered NASA's knowledge base about sonic boom recording methods, advanced ground-based microphone arrays, airborne sonic boom recording systems, and WiFi-controlled sensors and microphones.
Expanded polling methods: NASA refined data collection methods and test protocols for future public perception studies.
Supersonic Flight Research
Supersonic flight over land is currently severely restricted because sonic booms created by shock waves disturb people on the ground and can damage private property. Since the maximum loudness of a sonic boom is not specifically defined by the current Federal Aviation Administration (FAA) regulation, innovators at NASA have been researching ways to identify a loudness level that is acceptable to both the FAA and the public and to reduce the noise created by supersonic aircraft. Using cutting-edge testing that builds on previous supersonic research, NASA is exploring low-boom aircraft designs and other strategies that show promise for reducing sonic boom levels.
A variety of factors, from the shape and position of aircraft components to the propulsion system's characteristics, determine the make-up of a supersonic aircraft's sonic boom.