# Advanced Exercise Solution 5

```from __future__ import print_function

from math import log10

import numpy as np

from obspy.clients.arclink import Client
from obspy import Stream, UTCDateTime
from obspy.geodetics import gps2dist_azimuth
from obspy.signal.trigger import coincidence_trigger

client = Client(user="sed-workshop@obspy.org")

t = UTCDateTime("2012-04-03T01:00:00")
t2 = t + 4 * 3600

stations = ["AIGLE", "SENIN", "DIX", "LAUCH", "MMK", "SIMPL"]
st = Stream()

for station in stations:
try:
tmp = client.get_waveforms("CH", station, "", "[EH]HZ", t, t2,
except Exception:
print(station, "---")
continue
st += tmp

st.taper()
st.filter("bandpass", freqmin=1, freqmax=20)
triglist = coincidence_trigger("recstalta", 10, 2, st, 4, sta=0.5, lta=10)
print(len(triglist), "events triggered.")

for trig in triglist:
closest_sta = trig['stations'][0]
tr = st.select(station=closest_sta)[0]
trig['latitude'] = tr.stats.coordinates.latitude
trig['longitude'] = tr.stats.coordinates.longitude

paz_wa = {'sensitivity': 2800, 'zeros': [0j], 'gain': 1,
'poles': [-6.2832 - 4.7124j, -6.2832 + 4.7124j]}

for trig in triglist:
t = trig['time']
print("#" * 80)
print("Trigger time:", t)
mags = []

stations = client.get_stations(t, t + 300, "CH")

for station in stations:
station = station['code']
try:
st = client.get_waveforms("CH", station, "", "[EH]H[ZNE]", t - 300,
t + 300, metadata=True)
assert len(st) == 3
except Exception:
print(station, "---")
continue

st.simulate(paz_remove="self", paz_simulate=paz_wa, water_level=10)
st.trim(t, t + 50)

tr_n = st.select(component="N")[0]
ampl_n = max(abs(tr_n.data))
tr_e = st.select(component="E")[0]
ampl_e = max(abs(tr_e.data))
ampl = max(ampl_n, ampl_e)

sta_lat = st[0].stats.coordinates.latitude
sta_lon = st[0].stats.coordinates.longitude
event_lat = trig['latitude']
event_lon = trig['longitude']

epi_dist, az, baz = gps2dist_azimuth(event_lat, event_lon, sta_lat,
sta_lon)
epi_dist = epi_dist / 1000

if epi_dist < 60:
a = 0.018
b = 2.17
else:
a = 0.0038
b = 3.02
ml = log10(ampl * 1000) + a * epi_dist + b
print(station, ml)
mags.append(ml)

net_mag = np.median(mags)
print("Network magnitude:", net_mag)
```