Plane Colors

On map page, what do the plane colors mean? Also on the right where chart is. I guess the color rows refer to the plane colors on the map. On the map I never see green planes shown on the chart. On the map, I see grey and purple planes turning to white when tracked. On the chart I see green, purple and white rows. So, what are the color codes? Am I picking up and reporting all the planes I see on the map to FlightAware? Or just a certain color plane on the map.

If the map is coming from where I think it is

Green = The plane is transmitting the positional data and your Pi has received it

Purply/grey = Your Pi has received a a report from a plane without positional data, but so have some other people within 100km of where you are, data about the signal from all has been passed to a central computer that has calculated where the plane is by combining all the data (this is called MultiLateration) and passed that position back to you for display (as a thank-you for contributing your bit)

White in the table = Similar to Purply/Grey, except there are not enough people getting the signal (which has no positional info, so cannot be plotted on the map) for multilateration to work - so it’s displaying what’s been recieved. Could also be where the receiver thinks its got a recognisable signal (it passes all the checks) but in reality it’s just garbage.

HaHa, Proves me wrong

I’m now seeing white data lines in the table with MLAT positions / distance

(I’m assuming these are MLAT positions where I can ‘see’ the plane but have not contributed to the location calculation)

Latest dump1090-mutability I assume. These are aircraft where you have previously received a position (mlat or ads-b), and you are still hearing messages from the aircraft, but there haven’t been any positions available for >60 seconds. After 60 secs without a position they will turn white and the marker will be removed from the map. You can get the historical track by selecting the row in the table.

This usually happens because the aircraft is no longer in range of 4+ receivers for mlat - often happens as they descend. It can also happen with ads-b aircraft on the very edge of your range, where you can decode the shorter altitude/squawk replies but not the longer position messages.