[Image: Photo by John Gay: an F/A-18 creates a condensation cone as it breaks the speed of sound].
An email was sent out last week from the Regional Public & Private Infrastructure Collaboration Systems (RPPICS) – an organization with no apparent web presence – warning many businesses in and around Los Angeles that city residents “could hear up to a dozen sonic booms this morning [June 11] as some NASA F/A-18 aircraft fly at supersonic speeds around Edwards Air Force Base.”
While the “loudness of the booms will vary,” we read, these are only “preliminary calibration flights for an upcoming NASA study” that will research how “to reduce the intensity of sonic booms.” Part of this will be studying “local atmospheric conditions,” including air pressure, wind speed, and humidity, as these all entail acoustic side-effects.
It’s a sonic cartography of the lower atmosphere: an echo-location exercise. The geometry of noise.
Sound-bombing L.A. from above in order to know the exact acoustic shape and structure of the sky.