Auxiliary Channel Three Hour Release
A large number of sensors are used to record the
state of the LIGO instruments and their enviornment.
This data release contains sensor data recorded
in around 500 channels at each LIGO site. These data
represent three hours of time centered on
(GPS 1186736512 — 1186747264). Strain data
from the same period are available in the O2 Data Release
The data are available as down-sampled HDF5 files [19 GB], or
full sample rate GWF files [68 GB]:
Data may also be accessed from a network data server (NDS2) using
the NDS2 client
from gwpy.timeseries import TimeSeries
data = TimeSeries.fetch('L1:LSC-DARM_OUT_DQ', start=1186741850, end=1186741870, host='losc-nds.ligo.org')
NDS2 Example Code
Example software is available in an associated git repo
. To work with GWF files, see the software page
This data set is designed to be used for subtracting
noise sources - especially controls noise - from LIGO data.
Channels included in this set are those most likley to
include a coupling to the gravitational wave strain channel,
and so are possible sources of noise.
shows each channel with a few properties:
- Channel name
- Desired sample rate: The sampling rate in the down-sampled, HDF5 data
- Notes: A brief note explaining the meaning of the data in the channel
- Calibration: Where available, a calibration factor is included. Most channels are not calibrated.
- Units: Where available, the units corresponding to the calibration factor
In some cases, data for a given channel may not be available. These are marked "invalid" in the HDF5 files, and the corresponding channel may be
absent from the GWF files. Unavailable channels may correspond to sensors that are not present at a particular site or not operational at a
Channel names including PEM are part of the "Physical Enviornment Monitoring" system, described at pem.ligo.org
. For information
about other channel names, see the references below.
This data release is the first of its kind. Is it useful for your research? How could it be improved? Please
send feedback to email@example.com.