Problems removing station xml response

Hi all

I’m attempting to remove the instrument response from a trace using obspy.core.trace.Trace.remove_response, the exact code being:

trac.remove_response(inventory=inv, output=‘VEL’, pre_filt=(0.03,0.05,19.9,20),zero_mean=False, taper=False)

I get the following error:

Traceback (most recent call last):
File “”, line 205, in
trac.remove_response(inventory=inv, output=‘VEL’, pre_filt=(0.03,0.05,19.9,20),zero_mean=False, taper=False)
File “”, line 2, in remove_response
File “/apps/developers/libraries/python-libs/1.4/1/bit-64-canopy-1.6.2/lib/obspy/obspy/core/”, line 231, in _add_processing_info
result = func(*args, **kwargs)
File “/apps/developers/libraries/python-libs/1.4/1/bit-64-canopy-1.6.2/lib/obspy/obspy/core/”, line 2673, in remove_response
output=output, **kwargs)
File “/apps/developers/libraries/python-libs/1.4/1/bit-64-canopy-1.6.2/lib/obspy/obspy/core/inventory/”, line 919, in get_evalresp_response
raise ValueError(msg)
ValueError: When no denominators are given it must be a digital FIR filter.

The station I’m removing the response for is CC.TCBU, the xml of which is linked below. It appears that as the instrument response stages are assigned as analog, they require a denominator in the xml file. This problem also occurs for the CC.WIFE station, which is also linked below. I have removed response for this station in the past, using trac.simulate and a SAC.PZ file and it worked fine.

I don’t fully understand the response removal process here but my question is: How do I remove the response in this case, is it just not possible through the remove_response method for these stations?

Any help you can give me would be much appreciated



Hi all

Sorry to be a hassle but does anyone have a solution to this?

Thank you in advance


Hi Josh,

We at the Pacific Northwest Seismic Network maintain the meta-data for those stations (network code CC) and the Coefficients part of the response definitely should not be labeled “Analog”. I’ll look into whether there is a problem in the dataless SEED or in the dataless SEED to StationXML translation; it probably is the former in which case we’ll make sure to submit a new dataless SEED file to the IRIS DMC.


Thank you very much Renate!