1. Plotting observing segments for O1¶

The data from the full Observing Run 1 (O1) have been released by GWOSC.

This example demonstrates how to download segment information into a DataQualityFlag, and then plot them.

All we need to do is import the DataQualityFlag object, and then call the DataQualityFlag.fetch_open_data() method to query for, and download the segments for all of O1:

from gwpy.segments import DataQualityFlag
h1segs = DataQualityFlag.fetch_open_data("H1_DATA", "Sep 12 2015",
                                         "Jan 19 2016")

We can then generate a plot of the times when LIGO-Hanford was operating:

plot = h1segs.plot(color="gwpy:ligo-hanford")
plot.show()

(png)

That’s a lot of segments. We can pare-down the list a little to display only the segments from the first month of the run:

h1month1 = DataQualityFlag.fetch_open_data("H1_DATA", "Sep 12 2015",
                                           "Oct 12 2015")

We can also download the LIGO-Livingston segments from the same period and display them alongside, as well as those segments during which both interferometers were operating at the same time (see Intersection (&) for more details on this use of the & operator):

l1month1 = DataQualityFlag.fetch_open_data("L1_DATA", "Sep 12 2015",
                                           "Oct 12 2015")
bothon = h1month1 & l1month1
plot = h1month1.plot()
ax = plot.gca()
ax.plot(l1month1)
ax.plot(bothon, label="Both")
plot.show()

(png)