Hi all,

at the moment I’m trying to calculate iterative RFs by using the PREM velocity model.

For some distances I get ‘empty’ receiver functions, it is happening when doing: rfstats(stream, phase=phase, dist_range=dist_range, tt_model=tt_model). My assumption is that there is a problem with the dist_range and the phase. I set P phase with a distance range of 30-95°, Pdiff for 95-105°, PP for 105-140° and PKP for 140-165°, which worked perfectly fine for the RF calculation using the iasp91 model.

Now using the prem model, I get problems with for example distances of 134° and 139°, 134° needs to be associated with a PKP, but it is not working to associate 139° with the PKP phase. I checked the arrivals using the taupy model, where I get PKP arrivals and I also checked the ray paths using cake. I also tried the phases P, PP, PKP and Pdiff (just to try, when it is working), but the rfstream is always getting empty after using rfstats.

So, do you have any idea how to solve this problem? Did I miss anything? How can I see, which distance range rf wants me to use for which phase, if it is not conform with the taupy model?

This is how my script looks like at the moment:

```
tt_model='prem'
for i in range(0,len(epis)): ####epis is epicentral distances
if 30<= epis[i] and epis[i] <= 95:
phase='P'
dist_range=(30,95)
elif 105<= epis[i] and epis[i] <= 140:
phase='PP'
dist_range=(105,140)
elif 140<= epis[i] and epis[i] <= 165:
phase='PKP'
dist_range=(140,165)
elif 95<= epis[i] and epis[i] <= 105:
phase='Pdiff'
dist_range=(95,105)
zrt=obspy.core.read('...........')
zrt.detrend("demean")
for s in range(0,3):
zrt[s].stats.station_elevation = stel
zrt[s].stats.station_latitude = stla
zrt[s].stats.station_longitude =stlo
zrt[s].stats.event_latitude=elats[i]
zrt[s].stats.event_longitude =elons[i]
zrt[s].stats.event_depth =edeps[i]
zrt[s].stats.event_time =UTCDateTime(edates[i])
stream = RFStream(zrt)
rfstats(stream, phase=phase, dist_range=dist_range, tt_model=tt_model)
```

Any help is very appreciated! Many thanks!