Thread: Invalid data being returned for network EM

Started: 2019-01-24 13:56:02
Last activity: 2019-01-24 13:56:02
Medlin Andrew
2019-01-24 13:56:02
Hi,


I am using the FDSNWS web service to query information about network and station metadata, using web queries such as http://service.iris.edu/fdsnws/station/1/query?net=EM&sta=*&cha=*&level=channel&format=xml&includerestricted=false&includecomments=false&nodata=404


For the results returned for network code EM, I am finding the they cannot be ingested into the obspy library. The reason for this is that there are numerous channel metadata elements in the IRIS database for network EM that return values greater than 360 degrees for the <azimuth> value of the channel. Such data is rejected outright by obspy which asserts the value range for azimuth is from 0 to 360 degrees.


For example:

<Channel code="LQN" endDate="2018-05-18T18:15:00" locationCode="" restrictedStatus="open" startDate="2018-04-29T21:00:21">
<Latitude>42.926235</Latitude>
<Longitude>-102.035522</Longitude>
<Elevation>1064.6</Elevation>
<Depth>0</Depth>
<Azimuth>363.4</Azimuth>
<Dip>0</Dip>
<Type>GEOPHYSICAL</Type>
<SampleRate>1E00</SampleRate>
<ClockDrift>0E00</ClockDrift>
<CalibrationUnits>
<Name>V/M</Name>
<Description>Volts/Meter</Description>
</CalibrationUnits>
<Sensor>
<Description>NIMS 2612-12</Description>
</Sensor>
<Response>
<InstrumentSensitivity>
<Value>4.05503E10</Value>
<Frequency>1E-2</Frequency>
</InstrumentSensitivity>
</Response>
</Channel>

This has the appearance of a data quality oversight, and I wondered if this is something that could ultimately be repaired in the IRIS database?


Sincerely,

Andrew Medlin



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