Localisation
^^^^^^^^^^^^

Finally, we can run the actual localisation::

    arts_run_localisation --config FRB190709.yaml --output_folder localisation_lowres --save_plots --verbose

As before, we first run the localisation at low resolution. Then we want to zoom in on the localisation region
and increase the resolution.

Let's see the output of the localisation script:

.. code-block:: text

    (py36) leon@zeus:FRB190709$ ls localisation_lowres/
    FRB190709_burst00_CB00_chi2.npy          FRB190709_burst00_total_conf_int.npy
    FRB190709_burst00_CB00_conf_int.npy      FRB190709_coord.npy
    FRB190709_burst00_CB00.pdf               FRB190709_localisation.npy
    FRB190709_burst00_CB00_snr_too_high.npy


The localisation area looks like this:

.. image:: ../../_images/FRB190709_burst00_CB10_lowres.png
    :width: 600
    :alt: Localisation region of FRB 190709

The source is really only localised in one direction, as it was detected in only one CB. The gaps in the contour
indicate the resolution is too low. There is no clear preferred region to zoom in to, but we can try running
the entire field at higher resolution. This is the same region at 2 arcsecond resolution, which required
about 25 GB of memory and took 4 minutes:

.. image:: ../../_images/FRB190709_burst00_CB10_highres.png

Some details about the final localisation region, as printed by the script:

.. code-block:: text

    INFO:arts_localisation.run_localisation:Localisation area is 17764.00 arcsec2 = 4.93 arcmin2
    INFO:arts_localisation.run_localisation:Best position: 01h36m16.4332s +31d51m03.8673s

Again, we can create a nice picture with HiPS. In this case the picture is zoomed in so we can see
the size of the minor axis of the localisation ellipse; the major axis is much larger than the image.

.. image:: ../../_images/FRB190709_localisation_highres.png
    :width: 600
    :alt: Localisation of FRB 190709 with DSS2 background