Newcomer's questions to piaware, tracking, etc.


#1

Hi!

As some of you know from my first post here then I am a newcomer to this forum and to the art of flight tracking, for these reasons I got a few questions, but first a line on my setup.

I build my receiver following the guidelines from the flightaware web site using Raspberry pi+, ADS-B receiver dongle, 16GB MicroSD card, WiFi adapter), the antenna that came with the ADS-B dongle (I know this antenna is not the best, but I had to start somewhere) running latest version of piaware. The whole build is located on my south facing terrace with a close to 180 degree line of sight to the sides and up. I have free line of sight to one of the final approach flight paths to the nearby airport.

My Questions:

  1. Is there a log I can check each day that shows the flights tracked during e.g. the nights and/or evenings?

  2. How come I see no squawks when I use the build in “tracker” accessed by the IP address of the box and :8080? I assume airlines from AA, TAM and so on uses squawk codes. See attched screenshot or can this only be decoded when accessing flightaware’s web?

  3. How come I mostly see only higher altitude flights, basically none on the final approach, I have many fights passing right over the antenna, but the more lower ones are not tracked - is this normal, or must I do something?

  4. How come when looking at My ADS-B page then the map is always empty - as per attached screenshot is this correct or?

Sorry for the long post!

Cheers Steen

https://dl.dropboxusercontent.com/u/107738878/FA%20Track%20271214%201%20sh.jpg

https://dl.dropboxusercontent.com/u/107738878/FA%20Track%20271214%202%20sh.jpg


#2

Welcome Steen,
I’ll try to answer your questions…

I don’t know of a log that tracks everything your receiver “sees”. Others have loaded their feed data into a (local) database, but that’s a rather large project to tackle. There’s also /tmp/piaware.out that is tracking the total count of what is being sent to FA.

I know on the flights I track in the US, I only see squawks on planes that are taking off or landing at nearby airports. I think ATC is looking to actively track them on radar using their squawk codes.

The antenna that comes with the dongle can work better if you place it in a small “ground plane” I had used the lid to a can of beans (about 2.75") before I built a colinear antenna. You might also see if you can set the gain of the receiver to auto (–gain -10) in the PROG_ARGS line of your /etc/init.d/fadump1090.sh, like so:


PROG_ARGS="--gain -10 --quiet --no-rtlsdr-ok --net --net-ro-size 500 --net-ro-rate 5 --net-buffer 5"

You might also want to try adding --phase-enhance to the args. It helps mine a bit.

It’s a really good idea to backup your /etc/init.d/fadump1090.sh before you edit it. You’ll need to use “sudo” in your edit command (I use: sudo vi /etc/init.d/fadump1090.sh)

That’s what my map looks like too. It only shows your location (or locations if you had more than one), not the flights you’re tracking.

I hope some or all of this helps.
Thad


#3

It looks like you are only hearing the spontaneously-transmitted “squitter” messages (notably, the position one), not the interrogation-reply-based messages. The squawk code is usually carried in replies to an interrogation from a secondary radar; if there are no interrogations, you won’t see any replies.

Perhaps your local ATC only uses the older ModeA/C for interrogation? Try adding --modeac to the dump1090 command line to decode that, too.


#4

Hi thadm77,

Thanks so much.

Thanks for the hint on the “ground plane” in fact I am working on something like that.
I am also trying to get the antenna higher up as that will give me a line of sight to the north.
Problem with that is the distance to the top which is more than the lenght od the antenna cable and the USB cable I put between the raspberry and the dongle. Where I am these days not much supplies.

I will try to do the gain setting, but for the “enhance” I read somewhere that it was not recommended to do the “enhance” - right or wrong?

Cheers and happy holidays - Steen


#5

Hello obj,

Thanks for the insight, it helps me to better understand the world of flight tracking.

I will for sure try to add “–modeac” to the dump1090, but any specific place in the file the code should be added?

Cheers and happy holidays - Steen


#6

I believe that it’s the --aggressive option that is not recommended.
In “limited” testing I’ve found --phase-enhance to be somewhat helpful.

I built the G7RGQ collinear (for about $10 US) and increased my plane count from about 50/day to about 200/day. Took about a hour and mostly spare parts I had around.

Good luck…


#7

Hi thadm77,

Yes, you right - my bad it was “aggressive” I read about, still learning…

obj, suggested I should add --modeac to the dump1090 “command line” do you happen to know how I find the right file to add to?

Cheers Steen


#8

/etc/init.d/fadump1090.sh


#9

Ahhh - got it its the same file I edited earlier…

Thanks so much N456TS!

Steen