RF, reading SAC downloaded via SOD

ObsPy Related Projects Related: rf
1

Fairly new to ObsPy; sorry a likely naive question, I have SAC files (network=US; station name=GLMI; components; BH1, BH2, BHZ) downloaded using SOD and want to calculate a receiver function using RF. Following the manual, I succeed to read:

from rf import read_rf, rfstats, RFStream
data = read_rf(‘US.GLMI.00.BH?.sac’)
stream = RFStream()

print('aa ', data[0].stats.sac.kstnm) returns:
aa GLMI

but the command:

stats = rfstats(station=station, event=event, phase=‘P’, dist_range=(30,90))

returns a NameError:

NameError Traceback (most recent call last)
in
----> 1 stats = rfstats(station=station, event=event, phase=‘P’, dist_range=(30,90))

NameError: name ‘station’ is not defined

I guess I do not understand RFStream and how to fill the “station” and “event” fields.

Thanks!

2

Hi, welcome!

If event and station info are already present in the SAC files,
please try the following code snippet

from rf import read_rf, rfstats
stream = read_rf('US.GLMI.00.BH?.sac')
print(stream)
print(stream[0].stats)
rfstats(stream)
print(stream[0].stats)

Your code does not define the variables station and event which are used in your call to rfstats.

Edit: read_rf already returns a RFStream object.

3

This works. Thanks for the help! As a side note, I did have to change EVDP in the SAC header because ObsPy’s TauP utility assumes km, not meters.

4

Interesting. If meters are standard for EVDP in SAC than rf should ideally take care of conversion to km on reading.

5

Not sure whether METERS are used consistently. DIST for example is given in KM.