EBME Forums Forums Free discussion Out of Hours Technology How's It Done?

With the news that 13 Squadron RAF is to be re-formed to join 39 Squadron (whose badge, appropriately enough, is a winged bomb) as on operator of the General Atomics Predator MQ-9 *RPAS's (known as Reaper) ... I'm wondering how all that works**.

That is, what (in general terms) is the technology that allows an airman sitting in the desert in USA, or for that matter, "somewhere in England" to control the aircraft flying over the war-zone in [wherever]. And, how quickly does the aircraft react to twitches at the joystick thousands of miles away?

* Remotely Piloted Air System ... but also known as an Unmanned Aerial Vehicle (and often - wrongly - a Drone)
** Lot's more on Wikipedia, of course

Your point is? Far as I'm concerned reaper is another indiscriminate weapon that has accounted for more civilian deaths than actual targets. If you've ever played Xbox or ps3 COD games you might understand this technology.
Goeff regardless of how high tech the satcom uplink is, it will always require grunts on the ground to do the graft.
Reaper and other drones are a tool, but the hard work will always be done by a bloke and a few of his mates. Unfortunately the RAF don't realise this, they are a support to warfighting not THE warfighting. Hopefully the next round of redundancies will get rid of a lot of the useless pr!cks.

Thanks for the rant, Glyn!

What's my point? Briefly put, I'm interested in the technology (not the "politics"). In particular, the control signal path.

Xbox et al doesn't work very well over thousands of miles (as far as I'm aware ... not ever having played with stuff like that myself).

Sorry posted after a few vinos, the result of another long crap day at work. Anyways I did have an a hypothetical answer to this but edited out just in case I contravened Opsec

13 Squadron RAF, 39 Squadron, winged bombs, Predator RPAS,s, what has all this got to do with a medical engineering website. Please do not answer - I'm interested in the technology not the politics.
If you are that interested, why don't you ask the Ministry of Defence or even ask 39 Squadron themselves. I'm sure they will be only too delighted to give you the answer.
Myself, I wouldn't even know what an XBox or ps3 looks like.

The forum is:- Free Discussion->Technology.

Thanks Mike. I know I can always rely upon you to reply to my posts with helpful comments.

Geoff, this may help understand some of the technical aspects to be overcome (gleaned from a web source)

"I'm speculating, others might know definitely. I should guess that it works like the internet. The signal would not be analogue, but digital. It will be divided up into small packets and re-assembled locally in your set in the right order. If your set detects an error (the software can do this to some extent), it sends a message asking for that part of the signal to be repeated and it shows it on the screen only when no error is apparent. This might account for a delay. It is just a suggestion.

Concerning the delay in moving the joystick in the UK or Nevada and the drone responding above Afghanistan, if they use satellites in geostationary orbit, then these are at 22,500 miles, giving a round-trip of at least 45,000 miles which does not account for the fact that a single satellite is probably not sufficient -- that is it has to bounce from one satellite to another and so it is 45000 miles plus X where X is the distance between the necessary satellites up in the sky.

Speed of light is 186000 miles per second, but there is a delay, clearly.

If they don't use geostationary satellites, but low -earth orbit (LEO) or whatever other earth orbits there are (medium??) then LEO is a maximum altitude of 1200 miles, but now with the help of pictures you have to figure out how many satellites that you have to bounce it off and its more than in the geostationary orbit case. So you are still going to get a delay.

Stuff to do with packets and the like is probably irrelevant, as even if it is an IP network, and data is packetised, there is probably the equivalent of a circuit-switched transmission opened up for the pilot, by the DoD network protocols, to ensure that when the joy-stick is moved the drone responds in the shortest possible time.

As if he relies on an IP network with no notion of QoS (Quality of Service) where he overrides other packets, then the situation would be very silly. It would be silly to have the pilot moving the joy-stick, the drone not responding. The DoD ensures some level of Quality of Service which means that drone pilots override soldiers surfing the web on DoD networks".

As a further thought, take off and landing's are controlled locally, because of the stick demand to control surface moved delay. This is because of the realtime risks of crashing.

Thanks for that, Sean.

Yes, there's clearly more to this than meets the eye. Although the "thing" (word used to mimimise any offence caused to the more sensitive souls in our midst) is apparently able to "loiter" for many hours on end (and sometimes at quite high altitudes), I'm also wondering if signals are also passed through manned aircraft, as well. AWACS, for instance.

And I'm guessing that "local" (in-theatre) ground-based uplinks may well be part of the overall picture, too.

I could be wrong (?) but I doubt the satellites communicate with each other. More like a process of uplink to sat-1, downlink to ground station, then uplink to sat-2 etc. when the "thing" gets passed from one satellite to another, I should imagine. Thereby increasing the time (delay) involved, of course.

Controlled locally? It was a similar story with "airborne laser-guided ordnance". Some of those needed a guy (guys) on the ground to have a laser beam on target (for the missile to fly down, if you like ... and/or to pinpoint [light-up] the target).

By the way, stuff like this could have a "medical" application as well, could it not? For example, the surgeon at Johns Hopkins* controlling the medical robot in [wherever].

* Other state-of-the-art medical centres of excellence are undoubtedly available.

OK ... moving on to the next "How's It Done"? ... how about Digital TV?

Not having owned a television set for well over twenty years, I admit to being somewhat "behind the curve" when it comes to TV (and terrestrial TV, especially).

However, following the recent "digital switchover" (analogue switch-off) I was obliged to get a TV set going in a caravan I was selling. Luckily, I found a Freeview box in a skip, and (once I had dried it out, bought a SCART cable, and let the thing re-tune itself) was then able to have a go.

And what did I find? How about:-

1) Sound and vision losing sync
2) Squawking, pixellation and freezing
3) Signal dropping out

OK, that was right up on the Yorkshire coast (and perhaps not in the best of signal areas) ... but is stuff like that the norm? Is this really progress?

I think I much preferred "snow", ghosting ... and all the rest!

Anyway, it looked to me like it was a case of "99 channels and nothing on" (although I'll admit that I did enjoy a couple of episodes of "All Creatures Great and Small")!

Things being behind the times, out of tune, squawking and finding your latest hi-tech thing in a skip ... sounds like you and Yorkshire have a lot in common Geoff