PSBPI High Altitude Ham Balloon

In late June, an email arrived on the VK APRS list promoting another High Altitude Ballon Launch, this time from Bendigo (central Victoria). run by the guys!.

The Launch was slated for midday Saturday July 6th (what a nifty birthday pressie for me!), a small balloon carrying a Raspberry PI payload with Camera and LIPD 434mhz 25mw transmitter. the launch was a little late, the guys who run this appear to be learning and understanding the best way to get these to happen along the way. ++ The weather hadnt been the best very strong winds and some rain through Victoria.

This was the first lauch I had watched/followed/tracked that run a REAL time camera sending (slowly) images to the ground and to the server to create the images, crowd sourced with checksums, the images come down in small packets using RTTY at 300bps.

The details were:

  • – Frequency 434.650Mhz (+-10Khz), USB
  • – RTTY with 460Hz shift, 300 baud, 8 bit ASCII, no parity, one stop bit.
  • – Hardware is a Rev A Raspberry Pi, with a 25mW UHF transmitter module.
  • – Antenna is a quarter-wave with radials.
  • – Expected “cruising” altitude is 20km.

this SSDV software is a special version of fldigi, and optimised for high altitude balloons.

From home in Mt Waverley, on my small vertical in the backyard, I was able to track the balloon from around 45mins after launch (some issues with my end config, the flight team had changed the !) through to it crossing the coast near Orbost, others were able to track it as it headed to New Zealand.

The last transmission was received at 07:48 UTC, where it was at 17859m and 320km East of Lake Entrance, heading towards NZ at 141km/h.
We tried to raise our friends from NZ for further tracking but the timing wasn’t good, most people were sleeping! By now the batteries would have run out, or the balloon have bursted.

  • Max alt: 18556m
  • Distance travelled before losing contact: 690km, in 5h46m
  • Max ground speed >250km/h 
  • Maximum number of tracking stations for one packet: 14

These little balloons are great fun, cheap to make and easy to fly. I look forward to helping track the next one!.



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