SCAMP: Rapid Focused Sonic Boom Waypoint Flight Planning Methods, Execution, and Results

Abstract

Successful execution of the flight phase of the Superboom Caustic Analysis and Measurement Project (SCAMP) required accurate placement of focused sonic booms on an array of prepositioned ground sensors. While the array was spread over a 10,000-ft-long area, this is a relatively small region when considering the speed of a supersonic aircraft and sonic boom ray path variability due to shifting atmospheric conditions and aircraft trajectories. Another requirement of the project was to determine the proper position for a microphone-equipped motorized glider to intercept the sonic boom caustic, adding critical timing to the constraints. Variability in several inputs to these calculations caused some shifts of the focus away from the optimal location. Reports of the sonic booms heard by persons positioned amongst the array were used to shift the focus closer to the optimal location for subsequent passes. This paper describes the methods and computations used to place the focused sonic boom on the SCAMP array and gives recommendations for their accurate placement by future quiet supersonic aircraft. For the SCAMP flights, 67% of the foci were placed on the ground array with measured positions within a few thousand feet of computed positions. Among those foci with large caustic elevation angles, 96% of foci were placed on the array, and measured positions were within a few hundred feet of computed positions. The motorized glider captured sonic booms on 59% of the passes when the instrumentation was operating properly.

A Flight Research Overview of WSPR, a Pilot Project for Sonic Boom Community Response

“…One new aspect added to this technique was in-the-field audible cues borrowed from the Superboom Caustic Analysis and Measurement Program (SCAMP) project. 41 Once the PCBoom-derived sonic boom footprint was computed, the gradient of overpressure change as a function of distance downtrack of the waypoint was determined. If, after one of the passes the measured overpressure was higher or lower than desired, the Principle Investigator requested by way of the Mission Controller that the pilot shift his waypoint using the gradient to determine the amount of the shift.…”

SCAMP: Application of PCBoom to Measured Sonic Boom Focus Analysis

“…PCBoom was used for SCAMP experimental design 9 and flight test planning. 10 Accordingly, the first analysis performed after completion of flight test and data reduction was to process all flights through PCBoom.…”