Inmarsat ACARS

Sorry guys, did not realize that I had not blogged about my Inmarsat fun and games…..

There are a few different ways that aircraft communicate back and forth with the airline.
This blog is about satellite.
There is a geostationary (not moving, very handy, no tracking needed) satellite named Inmarsat (sorry, forget the exact number, there are a few of them) that carries, among other things, aircraft data.
To pick it up you need a small dish, an antenna, SDR (software defined radio) and a computer to run some software. We are going to be looking at the ACARS data on 1.545 GHz.

First things first. As it happens, I knew this day was coming so have been collecting satellite dishes behind the shed for a while, turns out I kinda lot track and have about 5 of them back there…. hey, its good to have options.

Next, you need an antenna or feed horn. So I did what all good hackers do and wound one around a toilet roll.

Next up, attache it to the dish and see if you can get some signal.
And we did, but the mounting was a bit unsustainable and looking out the window was also not the best, but here is how it looked for the test.

Next thing to try was jamming it in attic.
Let me tell you about the nice words that were expressed in getting the dish through the manhole and aligned to look at the satellite.

There is alfoil over the roof and it really killed the signal…..
Freddy came up with the idea of putting a pole on the side fence and hiding it behind some bushes out there, so thats what did.

Finally we had a good strong signal and a nice solid mount.
The eagle eye among us might notice that the feed horn is not the toilet roll. And your right.
I modified a GPS antenna and its much better as its smaller, flat and has better gain.
So with a 30 foot long USB lead, we now have a signal in the garage where we can use the software JAERO to decode the signal and stream it to my main dashboard.

You can see it here;!/4

Long term my plan is to get another GPS antenna and have a second decoder running to double my data rate.

So yeah, that’s how I pick up aircraft text messages from space.
Cool beans.