Max Range Performance Graph missing

[glen4cindy]

That's with the blue Flightaware stick and the 50$ AirNav antenna in a window?

With a gain of 49.6?
That's actually a little surprising.

But if you don't have any low flying planes closeby (in the direction of the window) then it's not too surprising.

Have you checked the theorectical max range?
(https://forum.flightradar24.com/thre...ange-I-can-Get)

One interesting question is how well you can see the horizon from the window.
If you see other houses then weaker signals are expected since unobstructed view of planes is limited.
You can also try suspending the antenna with a string from the ceiling an inch or so removed from the window, but as high as possible.

Could also be that you have mobile phone mast nearby giving you problems.
Can you post the signal graph?

The reason for the window is that it is very close to my computer where the network switch is, hence where the Pi gets network and power. The ceiling is low in that room so the window is about as high as it can get. It's far enough back that there are not many obstructions, but, there are some. We are 20 miles from KSTL as the crow flies. Also in this area is KCPS, KBLV,

[wiedehopf]

That's with the blue Flightaware stick and the 50$ AirNav antenna in a window?

With a gain of 49.6?
That's actually a little surprising.

But if you don't have any low flying planes closeby (in the direction of the window) then it's not too surprising.

Have you checked the theorectical max range?
(https://forum.flightradar24.com/thre...ange-I-can-Get)

One interesting question is how well you can see the horizon from the window.
If you see other houses then weaker signals are expected since unobstructed view of planes is limited.
You can also try suspending the antenna with a string from the ceiling an inch or so removed from the window, but as high as possible.

Could also be that you have mobile phone mast nearby giving you problems.
Can you post the signal graph?


The "strong message rate" in red is now actually a strong message rate.
It was showing the first derivation of the strong message rate before, so the gradient/slope of the graph you can see now

A 2 percent you can actually try increasing gain a little if you want.
But it's already a good setting. (0.5 percent to 5 percent strong signal messages is a reasonable gain setting in my opinion)

I'm pretty sure the antenna on the roof would bring big improvements.

Personally i like to use this LNA with the dongle from the same company: https://rtl-sdr.com/new-product-rtl-...mhz-ads-b-lna/
It deals much better with mobile phone noise and TV/radio transmitters.

[glen4cindy]

No need to do the install.sh again. (unless you want to update the rest of the receiver-project as well)
The graph generation scripts are used straight from the git directory.
So updating that directory with git pull and a reboot should be sufficient to update the graphs.
But he made manual changes it seems.

The reset --hard also cancels these manual changes and i don't know what he changed in build/portal/html/classes/template.class.php
So i'm reluctant to advise anything without knowing why that change is there.

I have already run the commands suggested by abdc567 when you mentioned I was using an older version and I tried to use:

cd adsb-receiver
git pull

to install updates.

I have not made any kind of changes, at least I don't think I have, other than configuring settings like lat/long. I also let the updates continue to run and never ran: git reset --hard origin/master.

After running all night, it looks like "Message" rate that is shown in red on the graph has dropped dramatically.

Screen Shot 2019-06-14 at 6.24.44 AM.png

[wiedehopf]

No need to do the install.sh again. (unless you want to update the rest of the receiver-project as well)
The graph generation scripts are used straight from the git directory.
So updating that directory with git pull and a reboot should be sufficient to update the graphs.
But he made manual changes it seems.

The reset --hard also cancels these manual changes and i don't know what he changed in build/portal/html/classes/template.class.php
So i'm reluctant to advise anything without knowing why that change is there.

[abcd567]

Try this:

git fetch --all 
git reset --hard origin/master 

./install.sh

Wanted to test above commands, but currently away from home, cannot access RPi.
Tested on my Android phone using terminal app termux:

$ git clone https://github.com/jprochazka/adsb-receiver.git
Cloning into 'adsb-receiver'...
.......
.......
1.52 MiB/s, done.
Resolving deltas: 100% (4171/4171), done.

$ cd ~/adsb-receiver     
$ git fetch --all
Fetching origin

$ git reset --hard origin/master
HEAD is now at 65efe86 Detect dump1090-fa and assign device index.

[glen4cindy]

Oh you already have a nice antenna .

Yeah in the window isn't optimal but it'll have to suffice for now.

Which dongle are you using, the green AirNav one?

I looked at my "Polar Plot" on FR24 and see this:

FR24 Polar Plot.png

The window I have the antenna in is facing South so I would assume that is why I have such a strong pattern in that direction.

I'm using the dark blue FlightAware one.

[glen4cindy]

Oh it seems you still have an old version, that doesn't handle that properly.
Try these commands:

cd adsb-receiver
git pull

Thanks for this. I attempted these commands and received the following.

pi@raspberrypi:~/adsb-receiver $ git pull
remote: Enumerating objects: 127, done.
remote: Counting objects: 100% (127/127), done.
remote: Compressing objects: 100% (15/15), done.
remote: Total 331 (delta 112), reused 123 (delta 112), pack-reused 204
Receiving objects: 100% (331/331), 107.71 KiB | 0 bytes/s, done.
Resolving deltas: 100% (233/233), completed with 42 local objects.
From https://github.com/jprochazka/adsb-receiver
f767266..65efe86 master -> origin/master
* [new branch] 2.x -> origin/2.x
* [new branch] 3.0 -> origin/3.0
* [new branch] bugfix -> origin/bugfix
* [new tag] v2.6.3 -> v2.6.3
Updating f767266..65efe86
error: Your local changes to the following files would be overwritten by merge:
build/portal/html/classes/template.class.php
Please commit your changes or stash them before you merge.
Aborting

Do I need to make my filesystem read/write? Or should I do something else?

Thanks again.

[wiedehopf]

Oh you already have a nice antenna .

Yeah in the window isn't optimal but it'll have to suffice for now. But considering that the reception isn't too bad.
(maximum possible range: https://forum.flightradar24.com/thre...ange-I-can-Get)

If you check the thread i linked, you'll figure out a suitable gain.

Make sure the antenna is pointing straight up, this is important for reception, even in the window.

Try having the RPi not too close to the antenna, the RPi produces electronic noise which interferes with reception.

With the cable attached to that antenna, i'd just put the RPi in the attic, the cable should be long enough for that?
Always tricky to find a way to get the cable inside through the roof of course.

Which dongle are you using, the green AirNav one?

[glen4cindy]

Oh it seems you still have an old version, that doesn't handle that properly.
Try these commands:

cd adsb-receiver
git pull

that should give you the current version.

You can get the percentage another way:

https://discussions.flightaware.com/t/thoughts-on-optimizing-gain/44482/2

You normally need at least a day to compare and even that can be tricky.
Especially because your reception seems rather limited anyway.

Check out this thread:
https://forum.flightradar24.com/thre...h-DVB-T-Dongle

This information is very helpful.

This is the antenna I am currently using:

https://www.amazon.com/gp/product/B07K7YW1XJ/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

It is not yet in its final mounting location. I have it sitting in the top part of a window but plan to move it quite a bit higher. I'm considering outdoor mounting boxes for the Pi once I settle on a location for the antenna. I'm sure outside and higher will give me much better coverage.

I'm also not sure I am getting the gain adjustment correct. Not knowing the following command:

sudo systemctl restart dump1090-fa

I have simply been rebooting the Pi after I made the gain change settings.

[wiedehopf]

Oh it seems you still have an old version, that doesn't handle that properly.
Try these commands:

cd adsb-receiver
git pull

that should give you the current version.

You can get the percentage another way:

https://discussions.flightaware.com/t/thoughts-on-optimizing-gain/44482/2

You normally need at least a day to compare and even that can be tricky.
Especially because your reception seems rather limited anyway.

Check out this thread:

https://forum.flightradar24.com/threads/9711-Optimize-the-Whip-Antenna-Which-Is-Supplied-With-DVB-T-Dongle

[glen4cindy]

There should be a percentage of messages >-3dB displayed. (first graph)

You don't want more than 5% of them, as a guideline.
But you don't want to turn down the gain too much either.

You all are helping me learn quite a bit and I really appreciate it.

Thank goodness for SSH not only because this setup is in another room but, because it is headless and getting things hooked up to make these configuration changes is tedious.

I'm curious how long I should wait and gather data before I update the gain again and reboot? It looks like the message rate dropped for 20 minutes and then came back up. That seems like it could very well account for at least some of the time for the reboot and then ramping back up.

This change is the 49.6 gain.

ADS-B Message Rate.png

[wiedehopf]

There should be a percentage of messages >-3dB displayed. (first graph)

You don't want more than 5% of them, as a guideline.
But you don't want to turn down the gain too much either.

[abcd567]

You have actually changed it from -10 (minus ten) to -8 (minus eight).

The -10 is the only value which can have a minus sign, and it actually switches the dongle to Automatic Gain Control. Any other value with a minus sign, like -8, will result in setting gain to ZERO, which will result in no aircrafts.

Change gain first to 49.6, then 45, then 40 and at each setting watch message rate. Do NOT use a negative value for gain.

[glen4cindy]

Oops, this was a copy-paste mistake due to very small screen of my phone. The dump 1090-fa does not have "dpkg-reconfigure", only "sudo nano".

I will now correct it. Use this one

sudo nano /etc/default/dump1090-fa

Thanks!

I was able to edit the file to add my lat/long.

Now, my IP_ADDRESS/dump1090.php is displaying range rings which it was not before, and the graph has just appeared. It was not there for awhile but it's there now and beginning to show data.

I'd also note, @wiedehopf suggested reducing gain a bit. I changed it from 10 to 8 and after the reboot my aircraft all but disappeared. I had 1 maybe 2 targets. Changing it back to 10 brought them all back.

[abcd567]

Oops, this was a copy-paste mistake due to very small screen of my phone. The dump 1090-fa does not have "dpkg-reconfigure", only "sudo nano".

I will now correct it. Use this one

sudo nano /etc/default/dump1090-fa