Raytheon live-demos DART-T Troposcatter communications

Yeah, we know it sounded kind of boring up in the title, but we have to admit we're a little intrigued by Raytheon's Marine field-test demo, which apparently proved the use of its DART-T Troposcatter atmospheric communications system. Bouncing signals off the troposphere, the DART-T achieved uninterrupted 20Mbps voice, video and data connections to another DART-T point. Certainly not tech civilians will be using any time in the forseeable future, but should space dust or a rogue enemy-state knock out some satellites, at least some kind of backup plan is in place for the military. In other words, us GPS-using, HDTV watching, bandwidth gobbling end-users will likely be left to fend for ourselves.

[s i d @ Feb 13th 2007 5:27AM]

this is HAARP right ? microwaving the ionosphere to create energy n data streams seems the way we r headed .... we have always got the leftovers from military technology guess thats the silver lining of the dark war cloud

[Dave @ Feb 13th 2007 6:15AM]

Troposcatter has been used here in Malayia for at least 15 years that I am aware of - Esso uses it to link their oil platforms to shore. I think bandwidth is prety poor though - 64kbps?

[satguy @ Feb 13th 2007 8:04AM]

The big deal here is the 20Mbps. Traditional troposcatter has been around since the 60's but only at rates of around 4Mbps. Also, the DART-T gives you multi-band operation, not just in the 4.5 to 5 GHz range. This was accomplished using the AN/TRC-170. Linked here: http://www.globalsecurity.org/military/systems/aircraft/systems/an-trc-170.htm

[Thomas Trautman @ Feb 13th 2007 9:40AM]

The TRC-170's are monsters. 2.2Kwatts+ out of the feed horn. You could warm your chow-up in front of the dish.

I miss working on those things.

http://www.vequalsir.com

[Eleventeen @ Feb 13th 2007 12:29PM]

AT&T used troposcatter as part of AUTOVON, back in the 60's.

http://coldwar-c4i.net/ATT_Project/Buckingham/index.html

[Drew @ Feb 13th 2007 12:34PM]

s i d:

HAARP is high altitude, ionosphere actually...which is hundreds of kilometers up. Troposphere is much lower, say 10 km, so it's less susceptible to interference and requires lower power transmitters.

The theory behind HAARP is a 'single bounce' technique...it actually requires making a 'dent' if you will, in the ionosphere. Tropospheric communications have multiple bounces. Same principle, different execution. Basically the same way you can hear shortwave broadcasts around the world.

[TrustButVerify @ Feb 15th 2007 12:41PM]

I'm with Satguy: this is evolutionary, not revolutionary. Tropo has been around for a long, long time. Without reading deeply it looks like modern waveforms and processing are finally being used- good for them, by all means, although it wouldn't be of much use in backing up comsats.
Anyone who mentions HAARP in this context is demonstrating their ignorance.