Auxiliary Channel Three Hour Release
Data Set
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
GW170814 (GPS 1186736512 — 1186747264). Strain data
from the same period are available in the
O2 Data Release.
Download Data
The data are available as down-sampled HDF5 files [19 GB], or
full sample rate GWF files [68 GB]:
HDF5 Data
GWF Data
Data may also be accessed from a network data server (NDS2) using
the
NDS2 client or
GWpy:
from gwpy.timeseries import TimeSeries
data = TimeSeries.fetch('L1:LSC-DARM_OUT_DQ', start=1186741850, end=1186741870, host='losc-nds.ligo.org')
See the
NDS2 Example Code for details.
Example Software
Example software is available in an associated
git repo. To work with GWF files, see the
software page.
Channel Descriptions
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.
The
Channel List
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
particular time.
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.
References
Feedback
This data release is the first of its kind. Is it useful for your research? How could it be improved? Please
send feedback to gwosc@igwn.org.
