Hello everyone,
I test AirSpay mini and FA Pro Stick on same location and equal antennas, and was surprised big difference of MLAT result.
I’m not sure, but I think MLAT for FA Pro Stick was changed only few seconds after reboot and then never change…
For FA Pro Stick I install Piaware and Dump1090-fa, like on this manual (flightaware.com/adsb/piaware/install), for AirSpy mini, - Piaware and AirSpy_ADSB and then configured location coordinates on FA site for both installations.
Why I have so big difference on MLAT?
Regards,
Yuri
Did you restart after configuring your location?
Yes of course. I reload it and have MLAT on site statistic, but so litle…
I see right possition of my QTH on dump1090 local site:
https://goo.gl/photos/grtf1sPgctmpm8wL6
I don’t know, may be if both sites over same IP it’s don’t work correct?
My config:
**site1:**AirSpy mini & RPi3 (piaware + airspy_adsb) ------------>
----------------------------------------------------------------------> NAT —> IP → Internet
**site2:**FA Pro Stick & Odroid C0 (piaware + dump1090-fa) —>
Is it this site you’re having problems with? flightaware.com/adsb/stats/user … tats-32233
It is reporting that the mlat timing is bad.
I would be suspicious of the odroid part of it. mlat timing requires good USB that does not drop any data, I don’t know how reliable the odroid is (maybe it is fine, I just haven’t tried one)
Can you try the prostick on the Pi 3?
I have both dongles. The FA dongle is way better than the airspy without an amp.
They are about the same when the airspy is used with an amp, however, in my situation(busy area) I need an Odroid XU4 as airspy_adsb requires a lot of CPU.
I suspect the gain is too high or a filter is not being used.
(This is clearly stated in flightaware.com/adsb/prostick/ )
I had to cut my fa dongle down to 38db with a cavity filter to get the best results.
Without the filter my aircraft numbers went from 200 down to 2.
This thread has a gain optimisation script that is really worth running on any RTL-SDR dongle
ads-b-flight-tracking-f21/gain-adjustment-t37172.html
@obj
Thank you for answer.
“Bad timing” it’s not wrong system time, it’s USB problem? Interesting, - after reboot board I have few MLAT packets in statistic.
OK, I try Pro Stick with RPi3 later.
@jonhawkes2030
I use Pro Stick with FA 1090 filter.
Thanks for info about Pro Stick gain, I try experiment with this level.
MLAT supported on both sites, but on Flightaware.com I see info for AirSpy (31699):
Feeder Type: PiAware 3.1.0
Multilateration (MLAT): Supported / Enabled (synchronized with 17 nearby receivers)
for FA ProStick (32233):
Feeder Type: PiAware 3.1.0
Multilateration (MLAT): Supported / Enabled
no info about syncronized… May be I need different external IP for this site for correct MLAT work?
PS FA Pro Stick looks very good for his price, and don’t requires so powerful CPU like AirSpy…
PSS I startup airspy_adsb with adding key “-g 21”, for maximum gain of internal LNA.
I found topic http://discussions.flightaware.com/ads-b-flight-tracking-f21/mlat-timing-scheduled-rebooting-piaware-t37601.html, look like board or USB dongle problem…
I don’t know what a difference but on same Odroid C0 with AirSpy mini MLAT works fine…
Feeder Type: PiAware 3.1.0
Multilateration (MLAT): Supported / Enabled (synchronized with 16 nearby receivers)
Same site 32233 - http://flightaware.com/adsb/stats/user/rz3dvp#stats-32233
With RPi3 FA Pro Stick works good and MLAT data is normal. http://flightaware.com/adsb/stats/user/rz3dvp#stats-33226
PS At the end of test.
On my QTH, FA Pro Stick look better: more aircrafts with low CPU usage level, low price, but not compatible with some boards.