About

[calendar]
start-of-week = sunday
start-date = 2015-09-14

[html]
issues = https://github.com/gwpy/gwsumm/issues

[state-H1-science]
key = H1-science
name = Observing
definition = H1:DMT-ANALYSIS_READY:1

[state-L1-science]
key = L1-science
name = Observing
definition = L1:DMT-ANALYSIS_READY:1

[tab-home]
type = link
name = _Home
url = https://gw-openscience.org/detector_status/

[tab-summary]
type = plots
name = Summary
foreword = The plots shown below characterize the sensitivity and
  status of each of the LIGO interferometers during the first half of the fourth observing run, known as O4a, which began on May 24, 2023 and ended January 16, 2024.
  For more information about the plots listed below, click on an image to read the caption.
1 = /s/summary_pages/detector_status/cache/O4a/H1L1-NETWORK_SEGMENTS_SINGLE-1368975618-20480400.png
1-caption = This plot shows the instrument status for the LIGO Livingston (L1) and LIGO Hanford (H1) detectors. The tall opaque blocks indicate times when the interferometer is intended to be in observing mode and no tests are currently being performed. The narrow transparent blocks indicate times when the interferometer was in an operational state, but not in observing mode. This state often means that testing or commissioning is in progress.
2 = /s/summary_pages/detector_status/cache/O4a/H1L1-NETWORK_SEGMENTS_MULTI-1368975618-20480400.png 
2-caption = This plot shows the time periods when the LIGO Livingston (L) and LIGO Hanford (H) detectors, were operating in coincidence, over the course of the day. The tall opaque blocks indicate times when the interferometers are intended to be in observing mode and no tests are currently being performed. The narrow transparent blocks indicate times when the interferometers wer in an operational state, but not in observing mode. This state often means that testing or commissioning is in progress.
10 = /s/summary_pages/detector_status/cache/O4a/H1L1-NETWORK_RANGE-1368975618-20480400.png
10-caption = This plot shows the average sensitivity of the LIGO Livingston (L1) and LIGO Hanford (H1) detectors to gravitational wave signals from binary neutron star mergers, as measured in megaparsecs (where 1 megaparsec = 3,262,000 light-years), averaged over all sky positions and source orientations. The value reported in this plot is determined by comparing the noise curve to a predicted gravitational wave signal from a binary neutron star merger. The sharp drops in this curve are typically due to transient noise in the interferometer limiting sensitivity to gravitational waves.
11 = /s/summary_pages/detector_status/cache/O4a/H1L1-COINC_OBSERVING_FACTOR-1368975618-20480400.png
11-caption = This pie chart shows the fraction of single, double and triple interferometer observing time for the LIGO Hanford and LIGO Livingston detectors.
20 = /s/summary_pages/detector_status/cache/O4a/H1L1-ALL_FF1C9B_HISTOGRAM-1368975618-20480400.png 
20-caption = This plot shows the total time the LIGO Livingston (L1) and LIGO Hanford (H1) detectors were operating at a given sensitivity to gravitational wave signals from binary neutron star mergers, as measured in megaparsecs (where 1 megaparsec = 3,262,000 light-years), averaged over all sky positions and source orientations. The value reported in this plot is determined by comparing the noise curve to a predicted gravitational wave signal from a binary neutron star merger. Low values of sensitivity in this histogram are typically due to transient noise in the interferometer limiting sensitivity to gravitational waves.
21 = /s/summary_pages/detector_status/cache/O4a/H1L1-MULTI_042056_TIME_VOLUME-1368975618-20480400.png
21-caption = This plot shows the cumulative time-volume of the LIGO Livingston (L1 and LIGO Hanford (H1) detectors, as well as a combined cumulative time-volume. This figure of merit multiplies the astrophysical volume that the detectors can observe by the amount of time spent observing, which allows LIGO scientists to calculate quantities such as the expected rate of gravitational wave signals. The combined time-volume is calculated by caculating the time-volume of the second-most senstive detector at a given time. 
30 = /s/summary_pages/detector_status/cache/O4a/H1-ALL_DUTY_FACTOR_SEGMENT_PIE-1368975618-20480400.png
30-caption = This pie chart shows the operational state of the H1 detector over the course of O4a. 'Observing' indicates time when the detector was taking data for use in astrophysical analysis. 'Ready' indicates that the detector was operating, but the on-site operators were taking measurements and the data were not fit for analysis. 'Locked' indicates that the detector was operating, but the data were not properly calibrated. 'Not locked' indicates that the detector was not operational.
31 = /s/summary_pages/detector_status/cache/O4a/L1-ALL_DUTY_FACTOR_SEGMENT_PIE-1368975618-20480400.png
31-caption = This pie chart shows the operational state of the L1 detector over the course of O4a. 'Observing' indicates time when the detector was taking data for use in astrophysical analysis. 'Ready' indicates that the detector was operating, but the on-site operators were taking measurements and the data were not fit for analysis. 'Locked' indicates that the detector was operating, but the data were not properly calibrated. 'Not locked' indicates that the detector was not operational.
layout = 2,2,2,2
afterword = This page is a product of the <a href='https://gw-openscience.org'>Gravitational Wave Open Science Center</a>. See <a href='https://gw-openscience.org'>gw-openscience.org</a> for more information.