The right way to read my data

Users Mailing List Archive
1

Hi all,
I just started my research and got a lot of data and was wondering how to correctly read it and remove the response.

The data I have is coming from six Trillium compact stations. The data is divided into days, so each station and and each day have the following data:

AE1.D
AE2.D
AE3.D
AE4.D
AE5.D
AE6.D
AE7.D
AE8.D
AEP.D
HHE.D
HHN.D
HHZ.D
LOG.L

And I have a poles and zeroes files which we downloaded from the manufacturer website :

Nominal Poles and Zeros - Trillium Compact
Zeros
0.00000 0.00000
0.00000 0.00000
-160.10000 0.00000
Poles
-732.00000 1415.00000
-732.00000 -1415.00000
-196.00000 231.00000
-196.00000 -231.00000
-173.00000 0.00000
-0.01772 0.01756
-0.01772 -0.01756
Gain
3.47000e+11
sesnsitivity 314572800

So far I’ve been only working with the HHE.D,HHN.D,HHZ.D files using a simple obspy.read and it works fine but I don’t know how to factor in the other files and the poles and zeros. All the examples I’ve seen use a station-xml file but I don’t have one. Thanks

Thanks,
Omry

2

Hi Omry,

AE* are state-of-health streams that contain supply voltage, internal temperature of the digitizer, etc. Usually those streams are not interesting for a seismologist and therefore not documented in StationXML. The response of those streams cannot be expressed using poles and zeros, but polynomial response could be used.

LOG.L contains log messages.

Regards,
Andres.

3

Hi Andres,
Thank you for helping,
When you write “The response of those streams…” you mean the AE*, right?
I want to use my poles and zeroes files for the HH* files, but I’m not sure about the right way to read it into obsby since I don’t have a stationXML. Could you point me in the right direction? Should I make my own stationXML?

Thanks,
Omry

4

Check out the `.simulate()` method that can be used with a simple
dictionary (leave out the `paz_simulation` part):
http://docs.obspy.org/tutorial/code_snippets/seismometer_correction_simulation.html#using-a-paz-dictionary

You should also consider using e.g. PDCC to create a proper full
response file for your experiment once and for all (dataless, can be
converted to StationXML using IRIS' Java tool
https://seiscode.iris.washington.edu/projects/stationxml-converter).

cheers,
T

5

Thanks a lot Tobias,
The simulate part was just what I needed, I’ve read that part of the docs at least 10 times but didn’t realize I can just drop the `paz_simulation’ part