I have noticed, from time to time, random “spikes” in the data from my device. I assumed that they were real, and resolved one day to try to track down what they were. This morning, I saw this:
That spike is sort of unbelievable. Especially since it didn’t appear on the HDF channel - but something similar did a while later:
Hmmm… looking at the EHZ spike in a bit more detail:
That looks odd … I really want to look at the raw data, but can’t find any tool to just pull the data out of the miniSEED files stored on the device … best I can doo it take a look at that using Swarm:
Hmm… interesting. No sign of any huge spike there. Looks like some sort of data corruption in the transfer/storage of the RS server??
Might be something for someone to take a look at?
Also, any pointers to a tool to extract raw data from miniSEED files would be welcome.
The answer to your question about extracting data very much depends on what tool you’re going to process them with:
Matlab - GISMO has some very clever routines, including ReadMSEEDFast
Excel - you could use mseed2ascii.exe available from IRIS, but it makes huge ascii files.
Python - ObsPy
etc
Hello Philip,
As also TideMan has said, there are multiple choices to read and extract data from miniSEED files. I personally love and always advise Obspy for Python, but a valid alternative is mseed2ascii.exe.
Regarding the spike, thank you for pointing it out to us. I checked a sample of other stations, and it doesn’t seem to appear that this was a server-wide event. I will nonetheless check again when I come back from the Easter period, and if you notice anything similar to this happening again, please let us know.
Thank you.
Here are two from me. My spectrogram looks the same as original poster as well.
You can also view miniSEED files directly using Swarm:
FIle :: Open File …
branden
mseed2ascii looks like it is what I was looking for. The source is on github and it looks well writtenans should probably build on my Mac with minimal to no changes.
Thanks for the suggestions.
1 Like
Just an FYI:
Took (literally) less than 30 seconds to download the source of mseed2ascii, unpack it and build it.
It does exactly what I need.
1 Like
There was another spike displayed on the DataView Helicorder this morning:
This isn’t a huge one, but I do see these pretty regularly, and became interested in tracking them down.
Looking at it a bit closer:
Doesn’t give much away, but it does give us a time.
So I pulled the miniSeed file from my Shake-Boom and extracted the data.
Next isolated the data for just the two seconds for 03:02:20 to 03:02:22 (10:02:20 - 10:02:22 UTC).
Only 200 values, but still, going cross-eyed looking at the numbers, so plotted it:
No spikes there. Maybe worth mentioning that I don’t see these on the HDF channel either, so that probably kills off my idea that this might be some sort of network glitch too - although that is pretty unlikely with a TCP channel anyway.
BTW: It would be useful to be able to select axis units between counts and the translated values, also time to be displayed in local or UTC.
1 Like
