Examining the launch pad noise environment for a small-lift launch vehicle

This paper presents a near-field analysis of acoustic data collected during liftoff of a small-lift launch vehicle. Challenges associated with collecting near-field acoustic data during liftoff are described. Despite these challenges, findings include (a) levels and spectra during the pre-launch static firing agree well with those during the hold-down phase of the launch; (b) spectrograms, coupled with trajectory data, provide aeroacoustic insights into the emergence of different noise sources from the flame deck; and (c) cross correlation is useful in identifying noise coming from different regions during hold-down and liftoff, including the trench, deck, and nearby structures.