Supersonic Flight Testing to Assess Ground Recording Systems for NASA’s Low Boom Flight Demonstrator
Forrest L. Carpenter, Lydia J. Hantsche, Larry J. Cliatt, Edward A. Haering · 2025
The National Aeronautics and Space Administration (NASA) has performed two supersonic flight test campaigns in preparation for the extensive ground measurements that will be taken during Quesst Phase 2 to verify the low boom from the X-59. The first test campaign was Carpet Determination In Entirety Measurements (CarpetDIEM) Phase II, with F/A-18B aircraft and a subscale ground sensor array and the second campaign was CarpetDIEM Phase III, with both F-15B and F/A-18D aircraft and a geographically large scale ground sensor array. CarpetDIEM Phase II served to evaluate prototypes of the state-of-the-art Ground Recording System (GRS) which NASA is developing in order to record the low boom of X-59. The prototype GRS measured both N-wave and evanescent wave sonic booms which were 1.4 ± 1.1 PLdB from co-located truth sources during these flights. CarpetDIEM Phase II was also used to downselect two NASA developed unattended trigger concepts, one based on Automatic Dependent Surveillance-Broadcast (ADS-B) and the other utilizing satellite communications. Both unattended trigger concepts performed well, with the ADS-B based concept being chosen at the conclusion of CarpetDIEM Phase II for integration with the GRS. CarpetDIEM Phase III was primarily a logistics risk-reduction effort for Quesst Phase 2, but also sought to evaluate the capabilities, including the newly implemented ADS-B unattended trigger, and ruggedness of the GRS during a long-term deployment. The F-15B stood in for the X-59, flying two different X-59 flight profiles, including an accelerating climb maneuver. The GRS successfully self-triggered to capture 80% of sonic booms generated from both steady and dynamic flight maneuvers. Low booms, defined by the project as being ≤80 PLdB, were recorded by the GRS near the end of CarpetDIEM Phase III. The GRS measured low booms were found to be within 0.4 ± 0.1 PLdB of a co-located truth source.