Traffic helicopters don't appear on the traffic map in case of their slow or almost zero ground speed

[k4gth]

Noticed this when one icon on the traffic map switched off and back time-to-time and turns out it was a helicopter. It's also relevant to the case when high flying plane also can switch off and on and when some plane slowly moving through the airport.

Tried to look into the code by myself but have no luck with figuring out how to adjust this logic (not enough skills in coding and never readed js code before). I mean, minGroundTrackDistance in TrafficTracker.js, ExponentialSmoother.js, "dt" value and so on. With various attempts to figure out possible solution it's either doesn't have noticeable effect or all traffic icons just disappear from the map.

The only success I've got is to change traffic icons and vector colors, in attempts to see dependencies.