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.

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Sparv Embedded AB
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58222 Linköping, Sweden
Phone: +46 (0)707 312608