I am trying to set up my location for MLAT on a new Raspberry Pi. After a while, my MLAT turned off because it said my location was not accurate. I looked at the longitude and latitude and it was off. I tried editing my location on Safari and Chrome on my Mac. It appears that you can’t manually type in the longitude and latitude. I was given the information from Google. The map shows up blank so I can’t choose the location. Has anyone else had this issue or a workaround?
The location is set on the flightaware website.
Select which site you want to update then click on the little gear icon to set the location
I tried that with Safari and Chrome. This is what it looks like when I click on edit location. No map, just a blank screen.
That’s the way it looks on my stats page also. I have seen a map previously. Possibly there’s a temporary problem at FlightAware?
Hi,
If you scroll further down that page with the broken map, you will find an option to select “I know my receiver’s location coordinates (advanced).” Select that, and then enter your lat/lon that you copy/paste from something like Google Maps or your favorite online site.
Regards,
-Dan
1 Like
That did it, thanks. It sure sounds like there are a lot of workarounds because Flightaware has some bugs to fix. At first I didn’t think the MLAT was working because I kept seeing the error after I saved it and it clicked on the button to send it to my pi but after a few minutes it went green. Hopefully me feeding Flightaware, Flightradar24, and ABSBexchange won’t cause my Raspberry Pi 3 to be overloaded and give the error. I suspect it was the location being off. “This feeder is not being used for multilateration because its timing information appears to be unreliable. This can be caused by the site location being incorrect, or because your Pi is running out of free CPU.”
Spoke too soon. MLAT shut off again. Same error. - I just looked at the logs on the setup page and it says my clock is unstable. Time to do some debugging.
Unstable clock relates to the clock within the SDR.
It is often related to issues with the USB port/bus.
From memory, the RPI3 shares USB with SDcard, Ethernet port and any attached USB devices.
Jon, would adding an RTC clock to the Raspberry Pi serve any benefit ? I have some of those available but just wondering if that will aid in the timekeeping. Never used those before (I got them as an added bonus when I bought some Pi’s recently).
If the issue is in the SDR clock that would be useless I guess ?
Some people know the hardware much better then I do so if you have some feedback that would be great.
Thanks. I had assumed the clock was inside the Raspberry pi. When I googled it, google AI said it was either a hardware failure, heat issue, or the pi was having issues because too many things were running on it. I assumed that having flightaware, flightradar24, and ADSbexchange was too much for the pi 4 so I was going to shut off some of those. I am going to try repimagine it. I may have imaged it as a pi 3 instead of a pi 4. - I will test it again. Next step, I will add back flightradar24 or ADSbexchange. I like feeding ABSbexchange because they will show you aircraft that are blocked. Is there any benefit to feeding flightradar24 that I can’t get on flightaware?
Latest update. I reload the pi and configured it as a Pi 4. Since there is a reload, ABSbexchange and Flightradar24 are no longer running. I am still getting the clock issue. I used the top command and I am using about 20% of the cpu.
Upon further research.
“AI Overview
Yes, a Raspberry Pi 4 is accurate enough for Multi-Lateration (MLAT) with
FlightAware, provided it’s properly configured with a reliable GPS source. The Pi’s internal clock is not the primary factor; accurate MLAT relies on external time synchronization, typically achieved by connecting to a GPS time source which provides a highly accurate Pulse Per Second(PPS) signal for time-stamping.
It is unclear if the timing that is inaccurate is coming from the Raspberry pi or the SDR. I wonder if I have a faulty pro-stick plus. I may post this as a new question since this thread has really changed directions.
I don’t think your SDR is faulty, we all see that message from time to time 
The AI is not quite correct.
The timing source is just the SDR oscillator and it’s only a short term timing source.
What usually is the issue is that there is too much going on with the USB controller and that can cause buffer issues in the SDR (small buffer).
For example using USB storage is often an issue as the bursts will cause data loss between the SDR and the pi.
Which in turn causes data to be missed and that can’t be compensated for because it is unknown how much data / time was lost.
Another common issues are low voltage arriving at the SDR.
That can be caused by an USB extension or just a power supply that’s not providing that much voltage.
If you have another sd-card to hand, give adsb.im a try.
That will take any software configuration out of the equation, it’s well tested and all config is done via the webinterface.
You can also enable mlat for lol / live / exchange and it will directly show you the mlat status for those sites.
If it works for those sites but not FA it’s not unlikely that the location on the FA stats page is still wrong.
edit: some people like the fr24 app. so that’s a reason to send them data i guess.
i’d just feed the sites you use or have used. maybe some others if they provide useful local MLAT results (fr24 does not provide local mlat results).
1 Like
I have tracked down the issue on one of my sites. It was the power supply, I used a generic 5 Volt 20 Watt unit and replaced it with an official Raspberry Pi powersupply. Since then there have been no under voltage messages anymore and the clock unstable message also hasn’t resurfaced.
Maybe this could solve your issue as well ?
1 Like
I doubt it is my power supply but I will try another one. It came in my Canakit. I would hope they provide a good power supply.
Thank you. I will try it when I get back in town.