Comment by Jack Crossfire on July 1, 2012 at 5:33pm

3D sonar was working really well when I gave up on it & no-one has made any traction with it, since then. 

Comment by Carl La France on July 1, 2012 at 6:27pm

Electronic warfare has been around since Vietnam and there are weapons capable of taking out any Jamming or " control signal  If the military felt threatened they would alter or shut GPS off .In this post they are  Talking about the old radio direction finder here they were becoming automatic and were getting  computing skills worked best up to 150 miles when Loran came along and put you within 16 ft 1,000 miles away Have a good day!

Comment by Garry Qualls on July 1, 2012 at 7:14pm

This sounds like what an iPhone does to get a location fix while it is waiting to get a GPS lock...triangulating off of cell towers and known wifi base stations.  The difference is that Apple has a database of all of these signal sources that was expensive to build and now must be maintained.  This approach sounds like it builds the database locally, onboard, as the vehicle moves around.  I'm kind of surprised we haven't seen a university or open source effort along these lines, since all the radios are getting so cheap and small...maybe it's out there and I just haven't noticed?

Comment by Crasher on July 2, 2012 at 2:29am

I can't believe it's that more difficult to jam huge swathes of frequency. Hell, a spark generator will do that. All the main useable frequencies are quite predictable, the only feasible solution seems to be inertial navigation.

Moderator Comment by Gary Mortimer on July 2, 2012 at 6:53am

Don't forget vision based systems are out there as well.

Comment by Crasher on July 2, 2012 at 7:30am

I think switching to a vision based is much more feasible than simply swapping one frequency for navigation from another Gary..

Moderator Comment by Gary Mortimer on July 2, 2012 at 8:42am

Good show Gary! There are astro nav plugins as well.......

Comment by Cliff-E on July 2, 2012 at 9:48am

So BAE's system can use pretty much any frequency, to me they just built a SDR that does GPS (i.e. time syncing). It's been done before. And considering the "big box", sounds about right. But I hope they solved the reflection issues that are more prevailing in terrestrial-based com systems to get clock accuracy close to what GPS provides.

Comment by Seppo on July 2, 2012 at 10:19am

This is very cool,... Though inertial systems would be the way to go,. Is there much out there usable/affordable for small uavs inertial wise ?

Comment by Helldesk on July 2, 2012 at 6:20pm

Like Skyhook, this could augment, replace or support GPS. Is the hard part in integrating the hardware that is able to pick up all kinds of usable RF? A very wideband antenna setup and the dedicated hardware to crunch the numbers to make sense of it all, and referencing it with its database, sure makes for an interesting system.

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