SR-71 sonic boom propagation experiment

Abstract

SR-71 sonic boom signatures were measured to validate sonic boom propagation prediction codes in support of the High Speed Research Program. An SR-71 aircraft generated sonic booms from Mach 1.25 to Mach 1.6, at altitudes of 31 000–48 000 ft, and at various gross weights. An F-16XL aircraft measured the SR-71 near-field shock waves from close to the aircraft to more than 8000 ft below, gathering 105 signatures. A YO-3A aircraft measured the SR-71 sonic booms from 21 000–38 000 ft below, recording 17 passes, including booms reflected off the ground. Three types of ground sensors were deployed to three station locations near the aircraft ground track, recording 172 signatures. Signatures of the F-16XL were also gathered. Atmospheric data were recorded for each flight. These results show that shock wave patterns and coalescence vary with SR-71 gross weight, Mach number, and altitude. This paper describes the design and execution of the flight research experiment, including instrumentation and flight maneuvers of the three aircraft. A guide to the entire digital database of sonic boom signatures, flight conditions, and atmospheric properties is included.