High Altitude Balloon Project help

Projects General Guidance
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I am a member of a group of 2nd year physics students from the University of Birmingham who are planning to send a camera and other instruments to 30km using a weather balloon. To track its journey and hopefully recover it once it has landed, we are planning to use a GPS tracker using an arduino board, and a radio receiver on the ground. While we have some experience of working with electronics, none of us are particularly proficient at working with such systems.

A similar project we have seen is, Hexoc.com is for sale | HugeDomains

I wondered if anyone could offer any advice with regard to creating/ operating such a system, or whether there were any resources you could recommend.

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Definitive (IMHO) work

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Could also PM JohnWasser, he was working just such a system with another group this summer.

And there's also the camera & cellphone in a styrofoam cooler unit ...

What will make your project unique from others that have occurred? I think as the grader of such a project I would be looking for something innovative.

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This is a passion of mine, despite only being involved in 1 flight to-date.

First off, I think the best method of tracking is to use APRS: You will need to get an Amateur radio license, but APRS was designed for this sort of thing and there is a pretty decent existing network in the US available without doing anything on your part.

Our testing showed that a fairly low-power radio (we used both a 1watt HT and a 300mW on-board transmitter) will be picked up no problem once you hit a decent altitude (5k feet or so).

You'll be able track the payload at nearly all times (assuming you splurge for a decent GPS; $50 or less) without having any assets in the field using a site such as http://aprs.fi. The only issue is during landing - you may have issues due to the terrain blocking radio reception (we had a recovery team in the landing area that picked up the last couple of packets that lead us directly to the payload).

For example, go to http://aprs.fi and change the "Show last" to 7 days, then enter "KF7OHV-11" as the Callsign to track and click search. Note this only works until Brett uses the tracker again (since this data is months old), so the link won't work forever.

You'll see red dots indicating each beacon sent. Note the transmitter was transmitting once every 2 minutes (roughly), and every packet (save the last couple) was received by aprs.fi. You can also mouse-over and see that we had stations picking up our transmissions from hundreds of miles. Not bad for a non-tuned 1/4 wave home-brew antenna.

I used a custom-built APRS tracker board based on the Trackuino project (http://www.trackuino.org/). Nice, simple, and solid. It simply works.

All the eagle files and source code is provided (if you want my modified boards, send me a PM and I'll include them as well - I switched to nearly all SMT with a much smaller board - the flight version was 1.5"x2.5" and cost $130 or so, the latest version is 1"x2.75" and I got the cost down to about $100).

We weren't sure if 300mW would be enough power, but in the future the only reason we will mess with anything else is due to cost (the Radiometrix HX1 is $50 + shipping and I sometimes get older used HT's for $25 or so) or the desire to receive commands from the ground.

I hope this helps,

Brad (KF7FER)

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APRS was our original plan, but after research we discovered that amateur radio cannot be used in unmanned airborne systems in the UK. Which is why we have chosen this alternative method on licence exempt radio frequencies, and it looks like most projects in the UK use this method.

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somnium:
APRS was our original plan, but after research we discovered that amateur radio cannot be used in unmanned airborne systems in the UK. Which is why we have chosen this alternative method on licence exempt radio frequencies, and it looks like most projects in the UK use this method.

Bummer. I guess that's what I get for being an ignorant American and assuming things

Well I'd add to the recommendation of the Radiometrix boards - they are fairly cheap and seem to be very reliable.

And it should be somewhat trivial to have someone knockup an Arduino clone (something like the RBBB) and add an on-board GPS and Radiometrix radio.

Take a look at:

http://ava.upuaut.net/?p=101

Both are UK-based projects and should be a good place to start.

I'd also add that CrossRoads made a great suggestion; perhaps this is an opportunity to do a bit of unique science as well?

Regards,

Brad.

PS While I loath GSM as a primary method of tracking, if you've got decent cell coverage in your recovery area it wouldn't be a bad idea to have something as a backup. A little insurance wouldn't hurt, after all without recovery pretty much all is lost.

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We had the same idea of trying something new and innovative with this project, but decided as this is our first attempt at anything like this we are going to keep it simple. But are hoping to do the same again next year and them try something new when we have more experience.

The rough idea at the moment is using
-Arduino UNO
-Radiometrix NTX2
-Suitable antenna
-Suitable GPS

Then a radio with laptop and dl-fldigi to track at the other end.