Swedish Ballooning Championship

The Swedish Hot Air Ballooning Championships is taking place now between April 27 and May 1. The pilots and crew of nine hot air balloons compete for the top position. The hosting organization is Dalslands ballongklubb. The location is the plains and forests around Kroppefjäll, to the west of Sweden’s biggest lake Vänern.

Windsond is used by the competition meteorologist along with other data sources to get a picture of the expected conditions for the next flight. Each flight of the competition needs to be planned ahead to be challenging and fair for all teams, and the weather conditions play an important role in the decision. Here’s a picture gallery in Swedish of how they use Windsond.

Two of the teams also cooperate in using Windsond to get detailed weather information during their flight. Up to four receivers are used to get real-time wind data to pilots and crews at the same time.

Of the seven soundings made so far, all sonds have been recovered and set up for new soundings. Predicting and controlling the landing location is working out well. At one point the competition organizers saw a sond drifting towards lake Vänern and could abort the sounding to save the sond.

Windsond evaluated

A customer deeply involved in hot air ballooning and gas ballooning sent me the story of his first test of Windsond. Naturally the system has already undergone a lot of testing but it’s reassuring to read his account.

The launch

Today it looked like a nice evening for a test launch, so I readied my balloon chase car, got my old ACER Travelmate C312XMI charged – and brought my 220v inverter with me.

It is pretty dark out, but nonetheless, I would not need to rely on visual contact with the sond, since the system would tell me exactly where this device is floating.

Ok, system running in the car, antenna mounted, external power supply working, GPRS mobile data service, map loaded, all systems green, one more beep – and release (for flight)!

As I have hoped, very slow wind conditions.
As I have feared with saving precious helium, a very slow ascent (1 m/sec), but that doesn’t hurt.

Ok, we now see clearly in physical reality — and on the Google earth display — the typical fine weather easterly flow, my first Windsond drifting very gently to the west. Daddy was the driver, I was glued to the Laptop Display, my mother in the back row.

Now it was easy to predict where we should go (read the position off GEarth ;-)
We went to a dark place, since then we would be able to observe (visually) better.
Then hopped to a next further stopping point, near the estimated landing positions, if we would release soon.

Bad thing was the local Fussball-game with its bright lights, and we were on the wrong side of the stadium, blinded by those beams. Anyway, I could not wait for the set altitude of 1500m AGL and sent the ‘cut’ command at about 1600 MSL or thereabouts. Too bad the wind shifted in those last 20 seconds of flight, although still slow, the track curved towards the stadium (we imagined trying to find the Windsond among 4.500 white foam cups of the visitors of the game …. ;-)

So cutting was sensible, or wait for the Windsond to go over the city – I did not want to climb to any roofs in the night. We could even follow the fall quite nicely, the flashing makes sense (for night trainings, anyway)

The recovery

Then repositioned the car to a closer road, hopped out (with Laptop, GPRS Modem but no external power supply) and got our feet dirty… Estimated landing was about 90 meters short, but no problem, we could even hear the “find me” sound and see the flashing of the Windsond.

Retrieved in no time, it was like finding lost markers, better than Easter anyway.IT IS A GREAT SYSTEM, I TIP MY HAT FOR YOU, THE CREATOR, DESIGNER, THINKER.
It is well thought through, it is reliable, it is usable, it is a dream come true – for me.

The customer suggested some improvements for the software which I’ll incorporate. I’ll also look into improving the 90 m inaccuracy of the landing prediction.

Business school

Course manager Anders Örnell and myself, branding my diploma

This Tuesday marked the end of the business course I’ve been attending one evening per week since September. The course gives an overview in several aspects of running a company; marketing, sales, entrepreneurship, service and law. It’s been a good starting point for mastering the world of business. The energy and entrepreneurial spirit of all participants and the interesting discussions also made an impression on me.


Instead of the business class, I’ll now spend my Tuesday evenings on something very different — a Bachata dance course.

Launching Windsond by a condom

The team and I launched a sond a few days ago by inflating a condom with helium. Condoms are much lighter than regular balloons but above all they improve the mood of the mission participants considerably. ;) The helium volume was estimated to 17 liters. This gave an average ascent rate of 1.5 m/s. The ascent rate given the neck lift 15.1g should be 1.0 m/s so the shape of the condom probably helped to improve the speed.

The condom burst a bit prematurely at 2400m AGL, a few hundred meters before the sond was instructed to let go. The temperature had dropped from 0*C on the ground to -12.4*C at this altitude. Although it’s doubtful condoms are designed to “operate” at freezing temperatures, the gas expansion at the altitude is the probable cause of the burst. On the other hand, a ground test showed a condom of the same model could contain over 40 liters of air before popping but maybe there are variations between copies. I considered to write a complaint to the manufacturer over this blatant product failure. ;-)

The launch was done in the evening, after dark. While the sond was still falling, I activated the beacon strobe by a button in the GUI. We were still 3-4 km away from the falling payload but the brief flashes of light were clearly visible, like a shooting star. The sond landed 65 m from the location originally predicted at 2400m altitude. In the dark, the blinking was very effective to locate the sond. The whole enclosure lit up and illuminated a meter of the ground around it. In the open landscape, the beeping was faintly audible at 200 m distance.

Another Windsond was also launched to compare the results of two data sources. They coincided very closely. The profiles of wind direction, wind speed, temperature and humidity were found to agree within tight margins. The second sond was launched while the first was still in the air which also demonstrated the ability of the system to handle multiple soundings at the same time. For the second sond I picked a landing location on a field close to a minor road. We picked up the sond 50 meters from the estimated position.

The double test was a big success and also very fun! A big thank you goes out to the team.