Something for folks familiar with launch acoustics. It seems to me that the volume, particularly the near sub sonic noise from Raptor static fires varies quite a bit from my rooftop viewpoint. One time the house will be shaking so much it feels like a carnival ride, and the next there will be little low frequency vibration and the audible noise seems relatively mild. Launches seem to be more consistent.
Do atmospherics, like inversion layers or wind speed/direction make a major difference in what you hear and feel from a mile and a half away when rocket engines light?
And, no Johnny, it's not how much beer I've had to drink before ignition.
I think you are correct, or at least heading in the right direction, with your logic.
I live near Gulf Shores, Alabama, and the peninsula blocking Mobile Bay from the Gulf of Mexico is the Navy's Blue Angels practice range. Because of my work I have been very close to, and sometimes underneath them during their maneuvers. When they are close to the ground, the reflections off surfaces in relation to the weather really makes for some interesting acoustics.
Yes, atmospherics definitely impact what you will hear from any sound source, but especially from low-frequency sources like big-ass rocket engines.
I recall an issue they had during the first F1 engine tests, that if there was a low cloud cover, nearby towns got shook near to death, whereas firing on clear days caused very little noticeable noise in nearby civilian locations. So, for large engines, they just didn't run tests on days with low cloud covers.
Do you notice a correlation between cloud deck height and the amount of sound you're hearing from the Raptors, Nomadd?
Wind direction also plays a huge role. High frequency noise is mostly impacted, low frequency noise less so.
I would expect if your prevailing winds are onshore, you're gonna hear it more loudly than you would on a calm day (or night).
I don't know if anyone from here ever really described the SN4 event. The lower frequency movie type explosion noise wasn't that bad. It was the rifle crack initial shock wave that hurt. I always regretted not having the camera zoomed out enough to catch the really cool looking detonation shock from here. None of the videos really did it justice.
I'm not sure if I'd want to be that close when twenty times that big a cloud detonated.
For some inexplicable reason, the city I live in fires off a cannon at noon every day from the exact same location. Knowing someone who fired this cannon, they usually use the same charge unless they're having some fun. On a day with low clouds it will shake the windows of the house I live in a few kilometres away. On clear days you wouldn't here it if you weren't listening for it.