Connex from Amimon - Going Digital Case Study by RotaRama

The challenge for UAV Operators

Video downlink is the perpetual weakness in most UAV operations, at least in the eyes of the clients I talk to. We now fly gloriously stable platforms with high-spec cameras, and (with a bit of luck) giving very few reliability issues. So why do we spend our lives peering at fuzzy analogue dowlinks in our monitors? 

Users of the latest DJI products will be cocking a snook of course, as Lightbridge downlinks have given them a taste of the rock-solid pictures we have been hankering for these past years. But alternatives for those of us flying custom rigs have, until now, been eye-wateringly expensive and scarily power-hungry.

That's why we were so excited when the Connex Amimon was launched at NAB. For £1300 you can now get a downlink advertising great range, and using the same chip technology as the likes of Paralinx, Teradek and Boxx. But does it deliver?

HD Video Downlink - but does it deliver?

We were lucky enough to give it a trial thanks to FirstPersonView. The challenge was to provide an airborne camera for coverage of British Rallycross on Eurosport in partnership with AMG TV.

On the whole, results were excellent. The Connex is trivial to set up and mounts very easily (in our case on the gimbal of our SkyJib octocopter carrying a Panasonic GH4). Power consumption was amazingly low as is the weight of both units. Latency of less than a frame was exactly as promised.  For professional purposes the lack of an HD-SDI output is one hitch, likewise the limited options for sending interlaced signals.

But what of the picture? Is broadcast quality a realistic proposition? To that I would give a 'yes, kind of'. The fact we had no break-up of images all day is remarkable, but a distances of over 250m there was some noticeable degradation in detailed parts of the image. The manufacturers say that the signal is uncompressed, but even at short distances there is noticeable blockiness in detailed textures which, to my eye, has all the hallmarks of some significant compression but is presumably an artefact of signal loss. I suspect this might be alleviated by switching to the 200mW power setting but the law doesn't permit that on 5.8gHz in the UK.

Connex - Real Time HD Action

That said, as a downlink for monitoring I would have no hesitation in using it. And I suspect you will see pictures beaming to the likes of news channels through a Connex unit very soon. 

Michael Surcombe is a pilot and camera operator with RotaRama (