[Bill S (OP)]

https://profmattstrassler.com/2017/09/27/ligo-and-virgo-announce-a-joint-observation-of-a-black-hole-merger/#comments

Considering the progress since the first direct observation of gravitational waves, it seems likely that, 
In the not-to-distant future, it may be possible to identify the galaxy in which the waves originate.

[evan_au]

Another gravitational wave detector in Japan is due to come online in the next year or so.

This  one use cryogenic cooling of the mirrors, which reduces thermal noise in the detector. The LIGO team in USA is considering this as an enhancement.

With 4 operational gravitational wave detectors, it should be possible to further refine the location of the gravitational wave source.

Lets hope that the continual background of earthquakes in seismically-active Japan does not mask the useful science.

See: https://en.wikipedia.org/wiki/KAGRA

[evan_au]

The addition of a third detector reduced the area of uncertainty by about a factor of 20.

There is a parallel band of uncertainty in the location of the source in the sky, because the 3 gravitational wave observatories (soon 4) are all in the Northern hemisphere, at somewhat similar latitudes.

To significantly reduce this band of uncertainty, a gravitational wave observatory is needed in the Southern hemisphere, which will allow triangulation in a different plane.

There is a prototype gravitational wave observatory managed by the University of Western Australia, at Gin Gin. However, the Australian government did not fund it for development into an operational installation (especially since no results had been demonstrated until LIGO's first observation, in 2015).

So, to produce much better progress in gravitational wave astronomy, an international consortium would need to fund an observatory in the Southern hemisphere (or in space). At least, now we know how to design a detector with the right size and sensitivity to detect real events.

See: http://www.abc.net.au/news/science/2017-09-28/gravitational-waves-detected-for-fourth-time-with-ligo-and-virgo/8994006