gwopensci 0.2.1

A python interface to the GW Open Science data archive

The gwopensci package provides an interface to querying the open data releases hosted on https://losc.ligo.org from the LIGO and Virgo gravitational-wave observatories.

To install:

pip install gwopensci

Searching for datasets

To search for available datasets (correct as of March 14 2018):

>>> from gwopensci import datasets
>>> datasets.find_datasets()
['GW150914', 'GW151226', 'GW170104', 'GW170608', 'GW170814', 'GW170817', 'LVT151012', 'O1', 'S5', 'S6']
>>> datasets.find_datasets(detector='V1')
['GW170814', 'GW170817']
>>> datasets.find_datasets(type='run')
['O1', 'S5', 'S6']

To query for the GPS time of an event dataset (or vice-versa):

>>> datasets.event_gps('GW170817')
1187008882.43
>>> datasets.event_at_gps(1187008882)
'GW170817'

Similar queries are available for observing run datasets:

>>> datasets.run_segment('O1')
(1126051217, 1137254417)
>>> datasets.run_at_gps(1135136350)  # event_gps('GW151226')
'O1'

Locating data URLs by event name

You can search for remote data URLS based on the event name:

>>> from gwopensci.locate import get_event_urls
>>> get_event_urls('GW150914')
['https://losc.ligo.org//s/events/GW150914/H-H1_LOSC_4_V2-1126259446-32.hdf5', 'https://losc.ligo.org//s/events/GW150914/L-L1_LOSC_4_V2-1126259446-32.hdf5', 'https://losc.ligo.org//s/events/GW150914/H-H1_LOSC_4_V2-1126257414-4096.hdf5', 'https://losc.ligo.org//s/events/GW150914/L-L1_LOSC_4_V2-1126257414-4096.hdf5']

You can down-select the URLs using keyword arguments:

>>> get_event_urls('GW150914', detector='L1', duration=32)
['https://losc.ligo.org//s/events/GW150914/L-L1_LOSC_4_V2-1126259446-32.hdf5']

Locating data URLs by GPS interval

You can search for remote data URLs based on the GPS time interval as follows:

>>> from gwopensci.locate import get_urls
>>> get_urls('L1', 968650000, 968660000)
['https://losc.ligo.org/archive/data/S6/967835648/L-L1_LOSC_4_V1-968646656-4096.hdf5', 'https://losc.ligo.org/archive/data/S6/967835648/L-L1_LOSC_4_V1-968650752-4096.hdf5', 'https://losc.ligo.org/archive/data/S6/967835648/L-L1_LOSC_4_V1-968654848-4096.hdf5', 'https://losc.ligo.org/archive/data/S6/967835648/L-L1_LOSC_4_V1-968658944-4096.hdf5']

This arguments for this function are as follows

• detector : the prefix of the relevant gravitational-wave interferometer, either 'H1' for LIGO-Hanford, or 'L1' for LIGO Livingston,

• start: the GPS start time of the interval of interest

• end: the GPS end time of the interval of interest

By default, this method will return the paths to HDF5 files for the 4 kHz sample-rate data, these can be specified as keyword arguments. For full information, run

>>> help(get_urls)

Query for Timeline segments

You can also search for Timeline segments, based on a flag name, and a GPS time interval as follows:

>>> from gwopensci.timeline import get_segments
>>> get_segments('H1_DATA', 1126051217, 1126151217)
[(1126073529, 1126114861), (1126121462, 1126123267), (1126123553, 1126126832), (1126139205, 1126139266), (1126149058, 1126151217)]

The output is a list of (start, end) 2-tuples which each represent a semi-open time interval.

For documentation on what flags are available, for example for the O1 science run, see the O1 data release page (Data Quality).