Raspberry Pi type B + DVB-T Dongle to feed FR24

[majo]

It certainly won't do any harm, as long as your sure the value is correct.

I did the adjustment a couple of days ago and since then I could notice slightly better results in range, aircrft seen and position reports!

Could you please give us some more information about your second adjustment concerning the "--gain -10" please?

[Oblivian]

MLAT
MLAT can only be contributed at this time by RPi and DVBT with Dump1090 capable of MLAT tag enabled
Mar '16 - ModeSBeast and Radarcape with 12MHz timestamps capable to be added

MLAT requires 4+ receivers.
- FR24 Receiver produced MLAT prioritised for accuracy
- Various combinations of receivers can contribute with GPS/time tagged receivers
- at least 1x FR24 receiver needed in combination
- All need to have contact with the same Mode-S Only aircraft (and 1x ADSB reference aircraft).

Attributed on the map caclulated from FR24 boxes as:
T-MLAT (Europe/Africa)
T-MLAT2 (North and South America)
T-MLAT5 (Asia/India/Japan)
T-MLAT3 (Oceania)

Attributed on the map calculated from RPi feeders:
T-MLAT6/7

More than 10 chars

[Paul30003]

Thanks for that follow up, Paul. But I still have a question about the MLAT radar sources that actually feed the FR24 server's web page.
My understanding is that MLAT data sourced from RPi receivers (or T-XXXXX feeders) still require a local FR24 receiver (or F-XXXXX feeder) to feed the MLAT calcs to the FR24 servers. MLAT 1/2 radar sources are from FR24 receivers and MLAT 5/6 radar sources are from RPi's. So far in my area MLAT 5/6 still is not working.

Your log files above show MLAT calcs are passed between local receivers but it doesn't prove that those calculations are directly passed from an RPi and displayed on FR24 as RPi sourced.

I think i'm going to have to agree to disagree, credit has been given to RPi feeders for their MLAT contributions, I'm only into about 7 pages of a thread of 73, but after doing my thorough research, if proved wrong, I surly will hold my hands up and stand corrected. http://forum.flightradar24.com/threa...ll=1#post68343

[Sam26K]

Thanks for that follow up, Paul. But I still have a question about the MLAT radar sources that actually feed the FR24 server's web page.
My understanding is that MLAT data sourced from RPi receivers (or T-XXXXX feeders) still require a local FR24 receiver (or F-XXXXX feeder) to feed the MLAT calcs to the FR24 servers. MLAT 1/2 radar sources are from FR24 receivers and MLAT 5/6 radar sources are from RPi's. So far in my area MLAT 5/6 still is not working.

Your log files above show MLAT calcs are passed between local receivers but it doesn't prove that those calculations are directly passed from an RPi and displayed on FR24 as RPi sourced.

[Paul30003]

Unless you are using an FR24 supplied ADS-B receiver, the last I heard you should not be feeding MLAT data directly to FR24.

As I understand it RPI's do not contribute MLAT data to FR24. I was wondering if this was due to the fact that FR24 receivers are GPS equipped and if RPI users had GPS enabled receivers would it be possible for those RPi feeders to contribute MLAT data?

The question has nothing to do with how accurately a user inputs their GPS coordinates which no doubt the accuracy varies between users. .

Edit: To clarify, as I understand it: At least 4 receivers spread apart are needed to calculate the MLAT position. As it is now, at least one has to be an FR24 receiver. Is this due to the GPS requirement? My theory is that if all ADS-B receivers in range of the aircraft are GPS enabled they would have more accurate MLAT calculations and would not require an FR24 receiver.

Your information is out of date. Raspberry Pi's without GPS do in fact aid in MLAT calculations. I enabled logging on my RPi and restarted the fr24feed service. Here are extracts from the log clearly showing MLAT is being used. The top section of the log shows the MLAT configuration, but further down, you can see that MLAT is indeed very active.

 
2016-08-03 12:39:40 | [main][i]Reader thread started
2016-08-03 12:39:40 | [master][i]Starting processing thread
2016-08-03 12:39:40 | [main][i]Socket server started
2016-08-03 12:39:40 | [bs][i]Initializing server
2016-08-03 12:39:40 | [main][i]MLAT data feed started
2016-08-03 12:39:40 | [bs][i]Starting server on 0.0.0.0:30003
2016-08-03 12:39:40 | [mlat][i]Waiting for MLAT configuration
2016-08-03 12:39:40 | [reader][i]Initializing reader
2016-08-03 12:39:40 | [reader][i]Connecting to DVBT receiver via (exe:///usr/lib/fr24/dump1090 --aggressive --ppm 70 --gain -10 --raw --mlat)
2016-08-03 12:39:40 | [reader][i]Connected to the receiver, configuring
2016-08-03 12:39:40 | [reader][i]Configured, processing messages
2016-08-03 12:39:41 | [reader][w]Setting new UTC offset: 0!
2016-08-03 12:39:41 | [time][i]Synchronizing time via NTP
2016-08-03 12:39:44 | [time][i]Time synchronized correctly, offset +0.0011 seconds
2016-08-03 12:39:44 | [main][i]Feed Network client started
2016-08-03 12:39:44 | [feed][i]Downloading configuration



2016-08-03 12:39:44 | [feed][c]GND: YES
2016-08-03 12:39:44 | [feed][c]NonADSB: YES
2016-08-03 12:39:44 | [feed][c]Timestamps: optional
2016-08-03 12:39:44 | [feed][c]Max range AIR: 350.0nm
2016-08-03 12:39:44 | [feed][c]Max range GND: 100.0nm
2016-08-03 12:39:44 | [stats][i]Stats thread started
2016-08-03 12:39:44 | [feed][i]defined 5 servers


2016-08-03 12:39:44 | [feed][n]connecting
2016-08-03 12:39:45 | [feed][n]connected via UDP (fd 22)
2016-08-03 12:39:45 | [feed][n]working
2016-08-03 12:39:45 | [feed][i]sent 11,0 AC
2016-08-03 12:39:45 | [mlat][i]MLAT configuration received, service ENABLED
2016-08-03 12:39:45 | [mlat][i]Starting MLAT with preconfigured position: xxxxxxxxx

2016-08-03 12:39:45 | [mlat][i]MLAT bandwidth reduction active, 
2016-08-03 12:39:45 | [mlat][i]Registering MLAT station
2016-08-03 12:39:45 | [mlat][i]Registering MLAT station: SUCCESS
2016-08-03 12:39:50 | [feed][i]sent 35,0 AC
2016-08-03 12:39:51 | [mlat][i]Received ADS-B time references AC:
2016-08-03 12:39:51 | [mlat][i] 40058A
2016-08-03 12:39:51 | [mlat][i] 400D8C
2016-08-03 12:39:51 | [mlat][i] 40621C
2016-08-03 12:39:51 | [mlat][i] 4CA6A4
2016-08-03 12:39:51 | [mlat][i] 4CA7AA
2016-08-03 12:39:51 | [mlat][i] 4D00D6
2016-08-03 12:39:51 | [mlat][i] 502CB6
2016-08-03 12:39:51 | [mlat][i] 75028F
2016-08-03 12:39:51 | [mlat][i] 896406
2016-08-03 12:39:55 | [feed][i]sent 40,0 AC
2016-08-03 12:40:00 | [feed][i]sent 48,0 AC
2016-08-03 12:40:00 | [mlat][e]Received MLAT timestamp error: 0 seconds!
2016-08-03 12:40:00 | [mlat][i]Pinging the server
2016-08-03 12:40:01 | [mlat][i]Stats 15072414/15072414
2016-08-03 12:40:05 | [feed][i]sent 48,0 AC
2016-08-03 12:40:10 | [feed][i]sent 47,0 AC
2016-08-03 12:40:15 | [feed][i]sent 45,0 AC
2016-08-03 12:40:20 | [feed][i]sent 50,0 AC
2016-08-03 12:40:21 | [mlat][i]Pinging the server
2016-08-03 12:40:21 | [mlat][i]Stats 15072414/0
2016-08-03 12:40:25 | [feed][i]sent 46,0 AC
2016-08-03 12:40:30 | [feed][i]sent 40,0 AC
2016-08-03 12:40:35 | [feed][i]sent 50,0 AC
2016-08-03 12:40:40 | [feed][i]sent 44,0 AC
2016-08-03 12:40:41 | [mlat][i]Pinging the server
2016-08-03 12:40:41 | [mlat][i]Stats 15072414/0
2016-08-03 12:40:46 | [feed][i]sent 48,0 AC
2016-08-03 12:40:47 | [feed][i]filtering out 41 overlapping AC (saving bandwidth)
2016-08-03 12:40:51 | [feed][i]sent 19,29 AC
2016-08-03 12:40:56 | [feed][i]sent 27,23 AC
2016-08-03 12:40:57 | [feed][i]removed 1 of 81 AC
2016-08-03 12:41:01 | [feed][i]removed 2 of 82 AC
2016-08-03 12:41:01 | [feed][i]sent 20,17 AC
2016-08-03 12:41:01 | [mlat][i]Pinging the server
2016-08-03 12:41:01 | [mlat][i]Stats 15072414/0
2016-08-03 12:41:05 | [feed][i]removed 1 of 84 AC
2016-08-03 12:41:06 | [feed][i]sent 30,23 AC
2016-08-03 12:41:09 | [feed][i]removed 1 of 84 AC
2016-08-03 12:41:11 | [feed][i]sent 31,21 AC
2016-08-03 12:41:16 | [feed][i]sent 20,22 AC
2016-08-03 12:41:16 | [feed][n]syncing stream async: 1
2016-08-03 12:41:17 | [feed][i]removed 1 of 89 AC
2016-08-03 12:41:17 | [feed][n]syncing stream result: 1
2016-08-03 12:41:21 | [feed][i]sent 39,22 AC
2016-08-03 12:41:21 | [mlat][i]Pinging the server
2016-08-03 12:41:21 | [mlat][i]Stats 15072414/0
2016-08-03 12:41:25 | [feed][i]removed 1 of 92 AC
2016-08-03 12:41:26 | [feed][i]sent 37,23 AC
2016-08-03 12:41:31 | [feed][i]sent 32,22 AC
2016-08-03 12:41:36 | [feed][i]sent 27,15 AC
2016-08-03 12:41:37 | [feed][i]removed 1 of 93 AC
2016-08-03 12:41:41 | [feed][i]removed 1 of 94 AC
2016-08-03 12:41:41 | [mlat][i]Pinging the server
2016-08-03 12:41:41 | [feed][i]sent 29,20 AC
2016-08-03 12:41:41 | [mlat][i]Stats 15072414/0
2016-08-03 12:41:46 | [feed][i]sent 29,18 AC
2016-08-03 12:41:47 | [feed][i]filtering out 52 overlapping AC (saving bandwidth)
2016-08-03 12:41:49 | [feed][i]removed 1 of 96 AC
2016-08-03 12:41:51 | [feed][i]sent 20,29 AC
2016-08-03 12:41:51 | [mlat][i]Received ADS-B time references AC:
2016-08-03 12:41:51 | [mlat][i] 34241A
2016-08-03 12:41:51 | [mlat][i] 3444D2
2016-08-03 12:41:51 | [mlat][i] 39950F
2016-08-03 12:41:51 | [mlat][i] 40058A
2016-08-03 12:41:51 | [mlat][i] 400965
2016-08-03 12:41:51 | [mlat][i] 4009D9
2016-08-03 12:41:51 | [mlat][i] 400D8C
2016-08-03 12:41:51 | [mlat][i] 405A46
2016-08-03 12:41:51 | [mlat][i] 405D13
2016-08-03 12:41:51 | [mlat][i] 40621C
2016-08-03 12:41:51 | [mlat][i] 406FDA
2016-08-03 12:41:51 | [mlat][i] 471EAB
2016-08-03 12:41:51 | [mlat][i] 4B19F4
2016-08-03 12:41:51 | [mlat][i] 4CA8E4
2016-08-03 12:41:51 | [mlat][i] 4CC4E9
2016-08-03 12:41:51 | [mlat][i] 4D00D6
2016-08-03 12:41:51 | [mlat][i] 51007F
2016-08-03 12:41:51 | [mlat][i] 75028F
2016-08-03 12:41:51 | [mlat][i] 896406
2016-08-03 12:41:51 | [mlat][i] AA64BA
2016-08-03 12:41:56 | [feed][i]sent 20,29 AC
2016-08-03 12:41:57 | [feed][i]removed 2 of 96 AC
2016-08-03 12:42:01 | [feed][i]sent 20,26 AC
2016-08-03 12:42:02 | [mlat][i]Pinging the server
2016-08-03 12:42:02 | [mlat][i]Stats 15072414/0
2016-08-03 12:42:04 | [feed][i]removed 2 of 99 AC
2016-08-03 12:42:06 | [feed][i]sent 20,25 AC
2016-08-03 12:42:08 | [feed][i]removed 1 of 97 AC
2016-08-03 12:42:11 | [feed][i]sent 20,28 AC
2016-08-03 12:42:12 | [feed][i]removed 3 of 98 AC
2016-08-03 12:42:16 | [feed][i]sent 20,27 AC
2016-08-03 12:42:16 | [feed][i]removed 1 of 95 AC
2016-08-03 12:42:21 | [mlat][i]Pinging the server
2016-08-03 12:42:21 | [mlat][i]Stats 15072414/0
2016-08-03 12:42:21 | [feed][i]sent 20,31 AC

[Sam26K]

I'm not so sure, I used google maps to pinpoint the location of my receiver. I would say, a GPS is an unnecessary expense, as your location is never going to move. I'm not sure if time needs to be accurate, I just checked the time on my receiver and noticed I was behind by an hour. My regional setting where in UTC but I should be on UK GMT, i'm sure there has been no mlat errors from my box else Flight radar would of blocked it.

Unless you are using an FR24 supplied ADS-B receiver, the last I heard you should not be feeding MLAT data directly to FR24.

As I understand it RPI's do not contribute MLAT data to FR24. I was wondering if this was due to the fact that FR24 receivers are GPS equipped and if RPI users had GPS enabled receivers would it be possible for those RPi feeders to contribute MLAT data?

The question has nothing to do with how accurately a user inputs their GPS coordinates which no doubt the accuracy varies between users. .

Edit: To clarify, as I understand it: At least 4 receivers spread apart are needed to calculate the MLAT position. As it is now, at least one has to be an FR24 receiver. Is this due to the GPS requirement? My theory is that if all ADS-B receivers in range of the aircraft are GPS enabled they would have more accurate MLAT calculations and would not require an FR24 receiver.

[Paul30003]

Hi Paul30003,

do you think the "ppm-correction" might work if I implement it into the existing extra settings like this:

procargs="--net --net-http-port 8080 --ppm 44"


Thanks,
majo

It certainly won't do any harm, as long as your sure the value is correct.

[majo]

Just a shot in the dark. It seems that the fr24 service is running as it should be. But you could try playing with your gain settings for your DVB-T stick.

Have a look at your fr24feed.ini file.

sudo nano /etc/fr24feed.ini

here is mine.

receiver="dvbt"
fr24key="xxxxxxxxxxx"
path="/usr/lib/fr24/dump1090"
bs="yes"
raw="no"
logmode="0"
procargs="--aggressive --ppm 70 --gain -10"
windowmode="0"
mpx="no"
mlat="yes"
mlat-without-gps="yes"

You may notice that I have extra settings.

procargs="--aggressive --ppm 70 --gain -10"

--aggressive uses more CPU, but I found that I tracked more aircraft by using this.

--ppm 70 is the frequency error in parts per million of my DVB-t stick. I found this, by using SDR# on my PC and tuning the stick to a known accurate signal, which happens to be the ATIS transmission from my local airport. Maybe ill do a little tutorial on this when I have a bit of spare time. This can increase range of your feeder.

--gain -10 sets the radio to auto gain.

I hope this can get you up and running. Also, I would disable logging, as this will wear out your sd card quicker as they have very limited write cycles. (logmode="0") Ill keep any eye on this thread and if I think of anything that may help, ill post again.

----EDIT----

Forgot to mention, if you do change /etc/fr24feed.ini you will need to restart your raspberry Pi

sudo reboot

or just restart the fr24feed service

sudo service fr24feed restart

You can also get information about fr24feed with,

sudo servce fr24feed status.

Hi Paul30003,

do you think the "ppm-correction" might work if I implement it into the existing extra settings like this:

procargs="--net --net-http-port 8080 --ppm 44"


Thanks,
majo

[Paul30003]

Related question about this FR24 8754 parameter:

"mlat-without-gps="yes""

If the RPi has a GPS receiver and this changes to "no" is it possible to contribute to FR24 MLAT network? (i.e. MLAT-6/7)

Or what is the status with FR24's RPi MLAT functionality?

Edit: IMHO a GPS receiver would result in more accurate MLAT results because it does not depend on the user to input the correct receiver's GPS coordinates and uses the GPS time stamp that is the same for all feeders.

I'm not so sure, I used google maps to pinpoint the location of my receiver. I would say, a GPS is an unnecessary expense, as your location is never going to move. I'm not sure if time needs to be accurate, I just checked the time on my receiver and noticed I was behind by an hour. My regional setting where in UTC but I should be on UK GMT, i'm sure there has been no mlat errors from my box else Flight radar would of blocked it.

[Sam26K]

Related question about this FR24 8754 parameter:

"mlat-without-gps="yes""

If the RPi has a GPS receiver and this changes to "no" is it possible to contribute to FR24 MLAT network? (i.e. MLAT-6/7)

Or what is the status with FR24's RPi MLAT functionality?

Edit: IMHO a GPS receiver would result in more accurate MLAT results because it does not depend on the user to input the correct receiver's GPS coordinates and uses the GPS time stamp that is the same for all feeders.

[Sam26K]

hi Everyone,
Can you help with a quick query please - I hope this isn't lost within this gigantic thread.

Current setup is Rasp B, 4.4.13+ ( Jessie ), clean install, with DVB-T dongle.
I have run & signed up with fr24feed.

My query is that I have not told the software what path the USB dongle is using, but IP:8754 tells me it is connected.
I also cannot see within /dev exactly which it is using either, which doesn't help. My FR24 Feeder Tracked Aircraft List is permanently blank too - I cannot tell whether I am incorrectly configured, or I just can't pick anything up ( I am not directly under a flightpath, although I am nearby ).

I am picking up a great deal from the threads available, but is there a diagram that shows the information flow within this system, it would help greatly rather than grabbing bits of info from lots of different threads.

Any help would be most gratefully received,

Regards
Martin

FR24 Link: Connected via TCP
FR24 Radar Code: T-LELO4
Aircraft Tracked (ModeS & ADS-B): 0
Aircraft Uploaded: N/A
Receiver: dvbt, Connected
MLAT running: NO

let's try again..

Have you tried "http:\\<yourRPisAddress>/dump1090"? (eg: 10.0.0.100/dump1090)

You should see a map. If there are no planes listed and you know they are in the area then most likely dump1090 is not connecting to your ADS-B receiver.

From your sequence of installations it's possible that you have the DVB-T receivers default drivers for tuning TV stations still installed.

My advice is to install dump1090-mutability per this thread:

Install dump1090-mutability 1.15

You might want to read the last few posts if you have some problems with it but in the end it's worth the effort. Only the first 8 steps are required to get you feeding correctly.

PS: Just because 8754 shows you as "connected" that doesn't mean dump1090 can access your DVB-T dongle. You probably need to re-install the rtlsdr drivers that is outlined in the dump1090-mutability 1.15 thread.

[Paul30003]

Many thanks Paul - I will do that .
My current fr24feed.ini file looks like this

ath="/"
bs="yes"
raw="yes"
logmode="2"
windowmode="0"
mpx="no"
mlat="yes"
mlat-without-gps="yes"

so I will modify accordingly.

Can you tell me what dump1090 actually does please?
thanks
Martin

dump1090 is what decodes the information. It is made available on port 30003, fr24feed listens to this port and sends the data up to Flight Radar. Here is a link to the Readme file on the creators github. https://github.com/antirez/dump1090/...ster/README.md

[it344x]

perfect, many thanks Oblivian - time to read..

[Oblivian]

Theres a rough outline of the flow process..

http://forum.flightradar24.com/threads/9866-Fr24feed-software-Additional-FAQs-and-Info

You should clear the path and source IP you have, although ignored when dvbt chosen the device path is not and will cause issues

Edit that out. Stop the service. Start it without service command and observe findings per suggestions within

Sent from my XT1092 using Tapatalk

[it344x]

Many thanks Paul - I will do that .
My current fr24feed.ini file looks like this

ath="/"
bs="yes"
raw="yes"
logmode="2"
windowmode="0"
mpx="no"
mlat="yes"
mlat-without-gps="yes"

so I will modify accordingly.

Can you tell me what dump1090 actually does please?
thanks
Martin