It's with great pleasure that the Paper Aircraft Released Into Space (PARIS) team today officially welcome aboard radio man Steve Daniels (callsign G6UIM), who's put together some tasty kit for the project and will be our in-the-field radio operator when launch day arrives. Steve's been building computers since 1979, when he …
Since Woomera is a little too far to use, maybe you could go down to the Needles on the Isle of Wight for the test flights.
Since the UK did it's rocket testing there, there is a certain symmetry.
I suspect its B/TEC rather than B-Tech.
Is that 433.950 frequency going to be the final one for position reporting? I'd love to monitor this :-)
Does GPS work above 60,000 feet? I seem to recall that is an inbuilt limitation to deter unintended military use?
Nothing that'll stop it working, I don't think. (Although you may get poor reception of GPS signals because you fall outside the main broadcast beam area) . You just can't expect the position to be calculated all that accurately.
Won't work at all
Civillian GPS units do indeed stop working at above 60,000ft (and faster than 1,000knots). It's deliberately hobbled to not work. Tim's right in that there is nothing technical to stop it, but the unit will just refuse to give a position.
Re: Hobbled for civvy use...
So, all you have to do is have a good number of these units (easier as they are small), and cycle them (power, probably), so that they will now know they are traveling faster than 1,000 knots? Of course, any automated flight system might want to stay slower than 1,000 knots to not reveal position its position due to sound or noticabilty on a (crowded?) radar image...
As far as altimeter, I would think it wouldn't matter much over 60,000ft? Or track against the carrier signals of satellite tracking stations where positions are known; don't have to decrypt them, just triangulate based on the frequency and do the maths?
Anon, because in some countries (hopefully not UK/US!) this might be sensitive info...
One thing to check...
Just one thing to check (although im sure you have this in mind) is to make sure that these components can handle the operational temperatures you can expect at release height or that theyre insulated well enough to accomplish this. This is a big problem with satellites, sounding rocket, and balloon launch tests - and one of the main reasons for failures of amateur/semi-amateur launches.
But if youve done that check then this looks good! =)
>Steve's been building computers since 1979, when he assembled his first UK101 while still at school.
Ditto, that or 1980, the minds a bit foggy.
From the link...
>SPEED 1 MHz. (could be 'overclocked' at 2 MHz by modifying the clock divide circuit)
This was the first mod I ever made, it was done by cutting a track on the board to bypass one of the divide by two circuits and using a switch to pass between 1 and 2 MHz.
Eeee, when I wer a lad things wer a lot simpler
You gotta a licence for that mate
Given you are transmitting in the 70cms Amateur radio band, you need to include a callsign in your morse message, - also needed for APRS which you appear to be using. The callsign needs to be registered to a holder of a Full UK amateur radio licence and you'll probably need a Notice of Variation from OfCom since amateur radio licences don't allow you to install equipment on airborne vehicles.
(Just in case you don't know all of this already )
Get your mate Steve (with the FT-817) to fill one of these out, just to be on the safe side:-
Good to see Amateur Radio on the Reg (and not just hams having a moan about RF spectrum pollution).
I'd also like to know if the 70cm frequency on the photo of the '817 is the one that will be used for the flight... I've got a log periodic, 817 and a big hill nearby :)
This is looking WELL EXCITING. Although I can't help thinking I'd be more impressed if you tracked the PARIS with a UK101.....
What is the estimated weight of the payload in the paper aircraft?
Yeah, I'm wondering about wing loading too..
Maybe they're going for a loose definition of "paper"?
Well done, folks...
I can't wait. Still can't understand why you don't launch from Rockall. Maybe that's a saga that a Vulture doesn't want to visit anymore..
The GPS module I use in the BeeLine GPS transmitter does indeed work above 18000 meters. It's only when it's above 18000 meters AND 515 m/s that it cuts out -- but we haven't test that yet ;) It's been part of payloads in high altitude weather balloons to higher than 100,000 feet MSL.
Weight of the GPS module transmitter with battery is just 55g, the FM beacon is 20g
Good luck Steve!
Greg Clark K7RKT
The Civilian GPS unit we are using will work fine above 60,000ft. 433.950 may not be the final frequency in use but it will be close.
I am aware of the rules for using Amateur Radio. And APRS.
The GPS payload weighs around 60g