Open jprochazka opened 6 years ago
We have these same issues across feeders in all MLAT areas. Keeping NTP server timings up to date is the easiest way without adding a GPS dongle. A GPS dongle with a Python script to keep the time updated would work but adds $20 and more complexity to the feeder setup.
MLAT just compares the receive time of the 1090MHZ Mode-S packet to on the others feeders receiving the same packet in the matrix. => since RF is predictable speed (roughly) .. that gives use a radius probability where the aircraft could be and it just solves for probable position using a bunch of feeders. I think I got that right. :)
Just the beast of MLAT.
EDIT: Not a good MLAT explanation. That's better way to explain it.
EDIT: MODE-C to MODE-S
As for jaggy tracks. That's just what happens when timings aren't in sync or signals are wonky. Solving the matrix is pretty CPU intensive as well.
Can we do better? Probably .. but also the problem can be people not using Pi images, or VRS, or Windows timings, etc etc
can I ask for clarification on this statement
MLAT just compares the receive time of the 1090MHZ Mode-C packet to on the others
Do you really mean Mode-C ? or do you mean Mode-S, my understanding is that pure Mode-C is not considered for MLAT, am I wrong, MLAT is tracking Mode-C transponders ?
ahh yes. mode s only. mlat can monitor - it just doesn't in this implementation
@adsbxchange You mentioned MLAT accuracy being effected by time settings which yes is true. Anything I can do to help out here with the script that you can think of? I have noticed a few jagged tracks especially in one area of my receivers range while others are smooth. I am guessing someone's timing is off in that area. Maybe somehow making sure the time on their device is proper and set to a reliable NTP server?