Digital Signal from News Helocopters

[mkewman]

With my FTA satellite setup I've noticed that many of the news choppers encode a digital squaking signal in some of their audio carriers.

what is this signal (you can clearly hear it in the attached link's video... may wanna turn down your speakers) and is there a way to decode it (if it's not encrypted of course) and how?

New York Videos, NY News Video, Video Clips | NBC New York

(on an offtopic note, whether you agree or not with the occupy movement this is a very interesting way of getting your message out. legal or not.)

 

[Romak3]

They should have put this up during the "winning" part of the massage.

 

[ka3jjz]

Not related to anything below 30 mhz - moved.

Mike

 

[mkewman]

my fault. I hadn't read that part.

I tried decoding it using mixW but couldn't get anything but gobbledygook.

Mystery digital signal by noodles734 on SoundCloud - Create, record and share your sounds for free <- download an mp3 there of the sound.

This digital signal is present on almost every satellite feed I receive of Helicopter footage. It's usually encoded via the microwave link back to the station on a secondary audio channel. I've also heard it on UHF media freqs before.

 

[mikegilbert]

That's most likely GPS position data from the Troll Skylink microwave system. It allows the mobile directional antennas to communicate with the base antennas to keep them aligned.

Troll Systems Corporation