Working With Station Data

The ASDF format stores station information in the StationXML format. Simply accessing the StationXML attribute will parse the data to an obspy.core.inventory.inventory.Inventory object if the station has one. Please see its documentation for more details of how to work with it.

>>> import pyasdf
>>> ds = pyasdf.ASDFDataSet("example_file.h5")
>>> ds.waveforms.IU_FURI.StationXML
Inventory created at 2014-12-09T19:43:16.000000Z
    Created by: IRIS WEB SERVICE: fdsnws-station | version: 1.1.9
            http://service.iris.edu/fdsnws/station/1/query?network=IU&level=res...
    Sending institution: IRIS-DMC (IRIS-DMC)
    Contains:
        Networks (1):
            IU
        Stations (1):
            IU.FURI (Mt. Furi, Ethiopia)
        Channels (3):
            IU.FURI.00.BHE, IU.FURI.00.BHN, IU.FURI.00.BHZ
>>> type(ds.waveforms.IU_FURI.StationXML)
<class 'obspy.core.inventory.inventory.Inventory'>

In some cases one only needs access to the coordinates and not the full station information including the instrument response. As parsing the full file is a fairly slow operation pyasdf offers functionality to very quickly extract the coordinates for any station. Either at the station level

>>> ds.waveforms.IU_FURI.coordinates
{'elevation_in_m': 2570.0, 'latitude': 8.8952, 'longitude': 38.6798}

or at the channel level (now the information is time-dependent!):

>>> ds.waveforms.IU_FURI.channel_coordinates
{'IU.FURI.00.BHE': [{'elevation_in_m': 2565.0,
   'endtime': 2011-09-03T08:00:00.000000Z,
   'latitude': 8.8952,
   'local_depth_in_m': 5.0,
   'longitude': 38.6798,
   'starttime': 2009-10-04T00:00:00.000000Z}],
 'IU.FURI.00.BHN': [{'elevation_in_m': 2565.0,
   'endtime': 2012-10-26T00:00:00.000000Z,
   'latitude': 8.8952,
   'local_depth_in_m': 5.0,
   'longitude': 38.6798,
   'starttime': 2009-10-04T00:00:00.000000Z}],
 'IU.FURI.00.BHZ': [{'elevation_in_m': 2565.0,
   'endtime': 2011-09-03T08:00:00.000000Z,
   'latitude': 8.8952,
   'local_depth_in_m': 5.0,
   'longitude': 38.6798,
   'starttime': 2009-10-04T00:00:00.000000Z}]}

The pyasdf library will parse the StationXML files on demand. While this will still read the whole StationXML file (and is thus I/O bound), it is much faster then parsing all the information:

>>> len(ds.waveforms)
196
>>> %timeit for station in ds.waveforms: station.coordinates
1 loops, best of 3: 512 ms per loop
>>> %timeit for station in ds.waveforms: station.StationXML
1 loops, best of 3: 3.18 s per loop

A convenience function to extract the coordinates for all stations also exists:

>>> ds.get_all_coordinates()
{'AF.CVNA': {'elevation_in_m': 1050.0,
             'latitude': -31.482,
             'longitude': 19.762},
 'AF.DODT': {...},
 ...}