Category Archives: dl-fldigi

Some more HAB tracking

I have been tracking some more of the High Altitude Balloons (HAB) that have been released over the last few weekends.

Last weekend (18th May 2013) saw the release of STRATODEAN2 from the Stratodean team, which I received quite well as can be seen from the telemetry stats.

Mark and Cassie have posted an update of the flight on their blog including an entertaining video

This weekend, there have been three more flights which I have managed to decode, track and update telemetry to the habitat website,

MONDO-12 which flew on Saturday 25th May 2013

BABSHAB which flew early this morning 

and finally this afternoon Dave Akerman’s PIE6, which used a Raspberry PI to preform the radio tracking. Details of the payload can be found here. In addition to the GPS the payload also contained a camera and the captured images were also transmitted using the SSDV protocol.

Each image is broken into smaller packets, while a receiver may receive all packets for an image it is unlikely it would receive all so by using the distributed network of multiple receivers the images are reconstructed on the habitat server.

The screen shot below shows my PC as it receives the packets and attempts to reconstruct the image, hopefully you can see some portions of the image are missing.

Dave used a very fast 600Baud RTTY so he could transmit the high quality images, so was impressed to receive anything as the combination of SDR# and DL-Fldigi can be hard work for my ageing PC.

However these are all the images I contributed to (from the habitat site)

One thing I didn’t receive much of were the interlaced telemetry packets.

99 Red Balloons, well actually 3 High Altitude Balloons on 434MHz

In my news feed this morning was an innocuous article from the Southgate Amateur Radio News website (which is a must have subscription for anyone interested in amateur radio)

It simply said “Several 434 MHz balloons launch today” but it was enough to pique my interest, the first launch this morning was the NSE/CHEAPO balloon set to launch at 9am from Bicknacre, Chelmsford, Essex, UK.

I was vaguely aware of these balloons and the High Altitude enthusiasts but I had never received or made any attempt at receiving them, but shortly after nine I started up the FUNCube Dongle and tuned to 434.650MHz with the discone in the loft and got a pretty decent signal, which I recognised as being RTTY.

A quick visit to the UKHAS UK High Altitude Society website and I had downloaded the dl-fldigi application which decodes the signal from and uploads the data to a central website.

I didn’t have any luck getting a decode from NSE but I was prepared for another attempt, so when I returned home this afternoon I managed to received the AURA balloon which launched from Great Malvern. I received quite a few success data packets which got uploaded.

I also received the last balloon this afternoon launched by the Queen Mary University from the Elsworth Site near Cambridge, around 4pm, but the signal was a little too scratchy for a successful decode.

I have since discovered that the transmitters in these balloons are only 10mW, but because of the line of sight they can manage several hundred miles, but even so the setup I was using wasn’t the most efficient for reception.

A similar balloon being launched