DC sonic boom

Yesterday the USA military fighter jets were scrambled to intercept an unresponsive plane (https://edition.cnn.com/2023/06/04/us/southwest-virginia-aircraft-crash/index.html) and allowed to go supersonic over the Washington DC area.

The population widely felt the resulting sonic boom, prompting many tweets and posts. Here’s what local BOOMs have recorded:

The pressure wave was evident in the first four tracks (stations closest to the possible origin point).

Sadly, the unresponsive civilian plane crashed in nearby Virginia with no survivors, as its pilot appeared to be unconscious in the cockpit.

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My station saw two events. I think the second one was real because I saw a press report with a trace from the Fredericksburg (USGS?) seismometer which showed the same thing. They said the second bump was a “reflection”. What it was reflecting from they didn’t say. The tropopause? A mountain?

The second one had a high enough magnitude to cause a little surface shake that was recorded by RS.

I see that RBE98 also saw some version of the second pulse and that it registered on their RS as well

This is another example of where it would be nice to have a TOA-based triangulation routine for RB’s.

PS: SWARM seems to only want to display “counts” for my station no matter what boxes I check.

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That’s a very interesting insight kpjamro; thanks for posting your data!

Many variables can condition a sonic boom propagation and detection: atmosphere conditions such as humidity, winds, pollution, temperature; the position of the observer; terrain conditions, and more. Do you have a link to the press report? I would be interested in reading through it as reflections of sonic booms have been detected by many geographical features, mountains, and even single buildings…

Regarding SWARM, you can try the solution I described here SWARM - Counts vs M/S - #6 by Stormchaser to see if you can manage to display Pascals on the software correctly.

Well that was kind of a can of worms.

I deleted the old community server from the pick list and created a new one per you instructions. I was seeing every station listed twice. So I restarted the program and it just hung up. I went into the config file and found that it had deleted the old server name from the config file but not the layout file - and that is what caused the hang.

Anyway, fixing that it is working, but still giving counts, not units.

and now I have this warning message in the console:

2023-06-06 09:08:35  WARN - could not get web service raw data (R176D HDF AM 00): Did not get an OK repsonse code (code=204, url=https://data.raspberryshake.org/fdsnws/dataselect/1/query?net=AM&sta=R176D&loc=00&cha=HDF&start=2023-06-07T01:07:45&end=2023-06-07T01:08:29"
2023-06-06 09:08:48  WARN - could not get web service raw data (R363F EHZ AM 00): Did not get an OK repsonse code (code=204, url=https://data.raspberryshake.org/fdsnws/dataselect/1/query?net=AM&sta=R363F&loc=00&cha=EHZ&start=2023-06-07T01:07:55&end=2023-06-07T01:08:48"

which repeats endlessly (30 second intervals) when stations are selected from the community server (my two selected above).

FWIW - I reverted from SWARM 3.2.0 to SWARM 3.0.0 with the same config files. I do not get the warning message with that version. Still get counts though. It seems to me I used to get units, maybe in an even older version (?) The SWARM manual says it will get the instrument response along with the data and use it. Maybe it does not understand my instrument response.

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Hello kpjamro,

Thanks for the detailed feedback; I tried to replicate what was happening with your console in my SWARM v3.2.0 installation, but with no success. The only element that is the same is the fact that stations are listed twice after adding the data source, no idea why this happens, but data seems to appear anyway whichever of the two stations are selected.

For the conversion to standard units, this could also be related to the fact that SWARM is no longer updated by the USGS, and newer file/data formats could cause problems. I have always used it with counts, but I can understand the issue in a different situation.

It has to do with the new raspberry shake data source, obviously. Searching on the http 204 message it seems that it is a status response indicating that the source was not changed as a result of the transaction. So no problem. Perhaps this appearance of this message was subsequent to the last rev of SWARM and they do not know what to do with the message, except to display it as a “warning” - it’s really more of a status message. No worries then.

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There is a possible reflection path. It seems a bit longer than what the numbers indicate but the exact location of the sonic boom source is not known so I will leave it as “maybe” the explanation.

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F-16s tend to operate in pairs. Could the “reflection” be the second aircraft?

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Yes I thought of that. Press reports said “fighter jets” (plural). My thinking was that the pilots would fly within sight of each other - certainly less than a mile apart - and that does not match the time line.

But it is a possibility.

There was another report that the second impulse was caused by an “echo”.

I found that report.
https://twitter.com/ameliairheart/status/1665451508870049793

Reading down the chain of tweets, there are a lot of crazy statements. So I have to discount the echo theory now.

I also found there are people reporting earthquakes without using seismometers. More craziness.

It is a way to get public reports tabulated, I guess …

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Here is what I’ve captured from my shake and Boom (RBE98) that seems to correlate with the sonic boom, which was at 1510 on June 4th, 2023.
RBE98 Seismic and Acoustic capture of NOVA Sonic Book 060423 1510L

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w.r.t. the double sonic boom, the news reports I heard were that several fighter jets were scrambled but only two were authorised to go supersonic.

Al.

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This is what was reported locally. For some time, the Fairfax police were looking for an explosion, and I was listening to their P25 trunk when they reported that they’d been notified by the Pentagon that they were scrambled Jet fighters. I got this info slightly ahead of the news media. I thought that was kind of cool too.

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