[Jake0001]

I'm not sure how useful it would be.

In all likelyhood the events would be hundreds of lightyears away making the propagation sphere a planer phenomena when it strikes Earth assuming the "wave" has any discernable energy to be measured.

At near-lightspeed velocities and a relatively small window to observe the arc, the "difference" would be measurable in nanoseconds or less - under the assumption that Earth and/or its magnetic field doesn't distort the wave.

Probably just a scientist trying to drum up funding for his research. Not that I disagree with it, it could prove very useful someday.

[RightWhale]

it could prove very useful someday.

Of course. At this time nobody would know. So it is science, looking for new data. If they were developing something specific that used gravity waves to do something useful, that would be engineering. Science is finding new things all the time, not all of it has immediate application, but we keep looking and will keep looking until nothing new is found. Then we're done. Like physics was thought to be done 100 years ago. Except it wasn't done at all.

[El Gato]

You seem to have the wrong picture here. Yes the wave will be nearly planer, I least hope so, becuase if it wasn't that would mean something bad happened really near by. But planer waves still have direction of propagation, it's perpindicular to the "plane". Stations not coplaner with the wavefront will still see the wavefront at different times. Those time differences are what allows for determinations of direction. It's the same principle that interferometers work on, although those deal with continuous type waves, rather than a wave front per se. The radar seeker heads and tracking radars in aircraft almost all use a similar interferometer, albeit one with "different" signal processing. We radar folks call it "monopulse", for historical reasons.