Internet data

[kolaf]

With the increase of Internet-based tracking services such as opensky and safesky it seems that the availability of good traffic information on the Internet is growing. I would really like to add this traffic information to my skydemon instance so that I can get a better overview of nearby traffic. For instance, GA aircraft that are not equipped with a full ads-b transponder may use an app to share their position with one of these services. Integrating this into skydemon would help increase my situational awareness.

Since I already have a source for ads-d data in my stratux, I think it is difficult to inject multiple streams into skydemon. My thought is therefore to equip my stratux with a 4g modem and ingest one of these Internet-based traffic sources. This can then be deduped ( with preference to radio traffic) and merged into a single GDL90 stream to the client application (skydemon).

If no one is looking into this, but it seems useful, I would be happy to take a crack at making it work. However, I have not been able to find any guides for setting up the development environment and building a stratux image. If someone could point me in the right direction, that would be a great help. Even better if someone wants to do this themselves ;-)

[b3nn0]

I still think that the better approach would be to integrate something like this into the EFB.

• Complexity is the same wether Stratux merges the different sources, or the EFB does it - it's basically the same logic that needs to be implemented either way
• The devices that run Stratux often already have a 4g modem and a sim card

If you still want to try, go ahead though and we will see if it becomes useful 👍

Regarding dev env setup:
You basically have two choices

• Use VSCode and develop on a Linux PC
• Use VSCode with "SSH Remote" extension and develop directly on the PI.
  The first one is a bit harder to set up, the second one gives you a quicker dev<->test cycle and can also be used if you're not running Linux on your PC.

See also here:
https://github.com/b3nn0/stratux/wiki/Developing-Stratux

Noteworthy: the Wiki says that you can't debug on the PI.
This is only true for the current stable releases.
There is a beta version that uses an aarch64 instead of arm base image. If you use that, you can also transparently remote-debug on the PI with VSCode: http://abatzill.de/random/stratux-v1.6r1-eu023-abe79100.img.zip

EDIT: If you use that beta image, you can skip the "Native debug" steps and just use the "Launch rPI aarch64" debug target, which uses go's standard delve debugger. And I also recommend running "git pull" before you do anything, because the latest git version switched from git submodules to go modules.

[kolaf]

I definitely agree that this is better handled by the EFB. The problem is that for Skydemon Rob has explicitly stated that they are not interested in consuming Internet data at the moment because of the unreliable nature of 4g in airplanes. This is to some extent correct, but my experience in Norway is that the cell phone coverage is very good at typical GA altitudes. Since I cannot control Skydemon and believe I might be able to figure something out with stratux, this is left as the only option to get it working.

I have also considered whether it makes sense to instead make a "gateway" app on the phone that intercepts traffic from stratux, mixes it with Internet sources it fetches itself, and outputs of this to the EFB. This is a much more general approach, but given the way stratux and GDL90 works, I am not sure it is possible to intercept the stream and inject traffic. Is it perhaps sufficient to simply transmit a second GDL90 stream to the same port? So that the stratux (or any other receiver) is responsible for the radio traffic, and a phone app is responsible for the Internet traffic?

[b3nn0]

In the case of GDL90, I think it should be possible to just inject additional traffic messages. Never tried it though.
For Flarm-NMEA, that's not possible of course.

[kolaf]

Yes, that works. I did a quick python prototype I was able to inject my traffic as GDL90 messages in parallel with the data from stratux :). I think this is the best way moving forward, using a separate app on the phone for injecting Internet traffic.

[bboo1010]

I am trying to do something similar, but instead of internet traffic I am trying to incorporate traffic from a Zaon XRX PCAS device, which listens to Mode C replies and calculates relative bearing and distance for those targets.

Kolaf, I am a bit new to the GDL90, but would love to learn more about how you were able to inject additional traffic into the Stratux Traffic data. Thanks in advance.