Seagull,
Not far off the mark at all, in fact Honeywell already patented such a warning, see
https://www.flightglobal.com/news/ar...n-tool-314706/ and the Russian Federation proposed a similar system to the ICAO Wake Turb study Group a few years ago too. To my mind, the snag with such tools is that the devil is in the detail. It's not too difficult to predict the likely horizontal extent of the wake, but you need to establish the likely vertical position too, and that is very variable. Most of the time the vortices obligingly drift down below the generating aircraft and mostly, but not always, they have the good manners not to go too far below either. So mostly you can sail through the plan position of the vortex without experiencing anything, because it is either below you if you are at the same level as the generating aircraft, or above you, if you are one level below. Unfortunately, vortices have been known to float up above the generating aircraft or descend 1000ft+ below, and either way, they could give you a nasty surprise. Relying on the plan view alone will produce way too many false alerts.
I would love to see more work done on just making these damn things 'visible'. it is hard to accept that moving air with enough oomph to hold up an A380 can't be seen somehow.