Decimator example code

Decimating data and updating the metadata

This example uses data and inventory from a FDSN data server

from obspy.clients.fdsn import Client
from obspy.core import UTCDateTime

from tiskitpy import Decimator

# Specify FDSN server dataset
client_address = 'IRIS'
net = 'Z5'
sta = 'BB650'  # Trillium T240. 100 sps
loc = '*'
cha = 'HH*,HDH'
starttime = UTCDateTime('2014-01-01T00:52')
endtime = UTCDateTime('2014-01-01T00:55')

# Read data and inventory
client = Client(client_address)
print('reading data from FDSN server...')
stream = client.get_waveforms(network=net, station=sta, channel=cha,
                              location=loc, starttime=starttime,
                              endtime=endtime)
print('reading inventory from FDSN server...')
inv = client.get_stations(starttime=starttime, endtime=endtime,
                          network=net, station=sta, channel='*', location='*',
                          level='response')

reading data from FDSN server...
reading inventory from FDSN server...

print(inv)

Inventory created at 2024-04-17T12:52:36.157100Z
    Created by: IRIS WEB SERVICE: fdsnws-station | version: 1.1.52
            http://service.iris.edu/fdsnws/station/1/query?starttime=2014-01-01...
    Sending institution: IRIS-DMC (IRIS-DMC)
    Contains:
        Networks (1):
            Z5
        Stations (1):
            Z5.BB650 (SIO OBS ID BB650)
        Channels (8):
            Z5.BB650..HDH, Z5.BB650..HHZ, Z5.BB650..HH1, Z5.BB650..HH2,
            Z5.BB650..HXZ, Z5.BB650..HX1, Z5.BB650..HX2, Z5.BB650..HXH

# DECIMATE DATA by 100 and update inventory
decim = Decimator([5, 5, 4])
stream_decim = decim.decimate(stream)

[INFO] Decimating data from 100 to 1 Hz (100x)...
[INFO] Took 0.0 seconds
[INFO] Decimating data from 100 to 1 Hz (100x)...
[INFO] Took 0.0 seconds
[INFO] Decimating data from 100 to 1 Hz (100x)...
[INFO] Took 0.0 seconds
[INFO] Decimating data from 100 to 1 Hz (100x)...
[INFO] Took 0.0 seconds
[INFO] New data has [180, 180, 180, 180] samples

# Update the inventory to include the decimated channels
inv_decim = decim.update_inventory(inv, stream)

 WARNING: FIR normalized: sum[coef]=9.767192E-01;
[INFO] channel modified from Z5.BB650..HDH (100.0 sps) to Z5.BB650..LDH (1 sps)
 WARNING: FIR normalized: sum[coef]=9.767192E-01;
[INFO] channel modified from Z5.BB650..HH1 (100.0 sps) to Z5.BB650..LH1 (1 sps)
 WARNING: FIR normalized: sum[coef]=9.767192E-01;
[INFO] channel modified from Z5.BB650..HH2 (100.0 sps) to Z5.BB650..LH2 (1 sps)
 WARNING: FIR normalized: sum[coef]=9.767192E-01;
[INFO] channel modified from Z5.BB650..HHZ (100.0 sps) to Z5.BB650..LHZ (1 sps)

# Inventory now has 4 more channels (LDH, LHZ, LH1 and LH2)
print(inv_decim)

Inventory created at 2024-04-17T12:52:36.157100Z
    Created by: IRIS WEB SERVICE: fdsnws-station | version: 1.1.52
            http://service.iris.edu/fdsnws/station/1/query?starttime=2014-01-01...
    Sending institution: IRIS-DMC (IRIS-DMC)
    Contains:
        Networks (1):
            Z5
        Stations (1):
            Z5.BB650 (SIO OBS ID BB650)
        Channels (12):
            Z5.BB650..HDH, Z5.BB650..HHZ, Z5.BB650..HH1, Z5.BB650..HH2,
            Z5.BB650..HXZ, Z5.BB650..HX1, Z5.BB650..HX2, Z5.BB650..HXH,
            Z5.BB650..LDH, Z5.BB650..LHZ, Z5.BB650..LH1, Z5.BB650..LH2

# Combine the original and decimated Z channels into one stream
compare_z = stream.select(channel='*Z') + stream_decim.select(channel='*Z')
print(compare_z)

2 Trace(s) in Stream:
Z5.BB650..HHZ | 2014-01-01T00:52:00.002634Z - 2014-01-01T00:54:59.992634Z | 100.0 Hz, 18000 samples
Z5.BB650..LHZ | 2014-01-01T00:52:00.002634Z - 2014-01-01T00:54:59.002634Z | 1.0 Hz, 180 samples

# Plot the original and decimated Z channels
compare_z.plot()