Had been looking for this -great information - looks like I order another pi!
To get the coverage I am looking for I need to run a couple of different antenna’s. I had looked at a couple of dongles on one pi but prefer the simplicity of separate systems. Currently run one pi as experimental, but I think two on the main system with separate antennas combining the feed in the way described is the solution I have been looking for.
I have used 2 antennas positioned different location of property, feeding seperate dvb-t and separate RPis then aggregated the feed on one RPi, and fed Piaware from agregator RPi’s dump1090-mutability. All went ok, but when I enabled MLAT on aggregator RPi, Piaware start giving messages the MLAT wont work with aggregated feed of two receivers, and timestamp of two receivers are different. I synchronized ntp on both RPis, but Piaware kept on giving messages in log, and wont feed flightaware.
The timestamps used by mlat are a simple count of samples received from the dongle. They have nothing to do with the system clock and NTP will not change anything. You need to run a separate piaware for each dongle for mlat to function correctly.
Thanks Oliver.
That is what I have done when all failed:
Deleted line "/home/pi/pi1-to-pi2-aggregator.sh"from /etc/rc.local on aggregator (RPi2).
Deleted file “/home/pi/pi1-to-pi2-aggregator.sh”** from aggregator (RPi2).
Installed Piaware data feeder on the RPi1 also.
Now both RPis are independently feeding Flightaware, and both are MLAT enabled. The reason for using 2 RPis on same property is that there is no single location of antenna which can cover 360 degrees. Each antenna covers a different slice of the full 360 degrees. I live in an apartmen, and my antennas are indoor, placed near large windows, each window looking in a different direction.
**pi1-to-pi2-aggregator.sh was as follows:
#!/bin/bash
while true
do
socat -u TCP:feederIP:30005 TCP:aggregatorIP:30004
sleep 30
done