MiniSEED filesize issue

Users Mailing List Archive
1

I am writing daily miniseed files for data I am reading out of a winston waveserver database. The data filesize is showing up as 43M on the linux operating system. I wrote the file using steim2 compression.

print st

1 Trace(s) in Stream:

OK.U32A…BHE | 2012-10-29T00:00:00.525000Z - 2012-10-30T00:00:00.500000Z | 40.0 Hz, 3456000 samples

A one hour and two minute file downloaded from IRIS using dhi2mseed is only 180kb.

print st
1 Trace(s) in Stream:
TA.W34A…BHZ | 2011-09-05T22:00:00.000000Z - 2011-09-05T23:02:00.000000Z | 40.0 Hz, 148801 samples

This means that my daily files are roughly ten times larger than they should be. Does anybody have any thoughts on why I might be seeing this?

Regards,

Austin

2

Ciao Austin,

steim2 compression size depends on the content of the trace.

Did you try to download 1h files form various stations? Could
be that OK.U32A is e.g. more noisy than TA.W34A.

For Miniseed compression ObsPy uses the libmseed library written
by Chad Trabant of IRIS. So I guess the same library is used
in both cases.

Cheers,
mbyt