Guest post: more high altitude ballooning from Dave Akerman

Liz: Tomorrow, Eben and I are getting up at sparrowfart to go and stand in a field with Dave Akerman, where we will “help” him launch a balloon equipped with a Pi. This time the balloon, rather than going for an altitude record, is intended to travel a long distance laterally; we’re hoping it’ll make it to Poland in the 24 hours we have before its batteries run out. Here’s a guest post from Dave explaining what it’s all about, and showing you how you can track the balloon yourself, from home. See you tomorrow, Dave!

All being well I will launch the 5th “Pi In The Sky” this Saturday morning from Cambridgeshire. The intention is to get the balloon to float all day rather than burst, and the projected flight path takes it over Holland, Germany and into Poland. The batteries will last for 24 hours by which time it will be out of range of our radio receiver network anyway.

The payload will carry a model A Raspberry Pi, plus an Arduino Mini Pro, a UBlox GPS receiver, and 2 Radiometrix NTX2 transmitters. The latter will be on nearby frequencies primarily to avoid conflict with some other flights this weekend, but also to allow those with SDR (Software Defined Radio) receivers to listen to and decode the signals from both transmitters.

If you have an SDR and want to do this, check my article. If you’ve not tracked amateur high altitude balloons before, check the UKHAS tracking guide.

This will be one of 3 flights from the same location on Saturday:

Launch Announcement

On Saturday the 13th of April there will be three launches from the Cambridge area under meteorological balloons. Two of these (PIE5 and AVA) are configured to ascend to a certain altitude (>100,000 feet) and then float rather than burst. The expected path takes the balloons out of UK air space and continue onwards over Europe. The final flight (XABEN) will be a slow ascent and then a burst to land in Holland.

All balloons will be transmitting RTTY telemetry on the 70cms band.

The first balloon is flying a Raspberry Pi which will be transmitting live SSDV images back to the ground by a pair of transmitters to double the bandwidth. The data is RTTY 300 baud 8N2. The frequencies will be at 434.070 and 434.074Mhz. The balloon call sign is $$PIE.

The second balloon is flying a 70cms tracker on 434.450Mhz 50 baud 7N2, additionally once it enters air space where the airborne use of APRS is permitted a second APRS transmitter will enable with the call sign M0UPU-11.

The third balloon is callsign uXABEN, 434.350MHz, 470Hz shift, 7N1.

Live images from PIE will be displayed here

All balloons can be followed here

Anyone with suitable receiving equipment is welcome to assist tracking. We always welcome people joining the distributed network of listeners, instructions on how to receive these balloons is here.

Live chat and up to date frequencies and assistance will be on the #highaltitude chat room on You can connect here

Live video from the launch site will be streamed here.