Abseiling Beside the Road

#4 Essen – Kierspe
Vaisala RS41-SGP / P3510106 / 18.10.2018 1200Z
🔗 sondehub.org tinker sonde
🔗 radiosondy.info individual transport

The day before my holiday trip to England, Essen had another flight who looked nice. Together with flynamic we tried to observe the sonde during it’ s landing. We were there in time, only to be one road too far at the crucial moment: I had not noticed that Kierspe is 150 m higher than Gummersbach.

A little later we were at the landing site, which was supposed to be a few meters beside the main road. Parachute and balloon remainings were lying on the road and were overrun at second intervals. Fast action was asked, flynamic stopped beside the landing site at a parking bay, I jumped out and recovered parachute and balloon remainings of the road. After everything was secured, we made our way to the sonde, which turned out to be hanging in a deciduous tree at some height. Shaking it all didn’t help. At first I wanted to throw the string down the embankment of the road to get it closer to the probe, but it turned out that after a bit of shaking it was possible to abseil the sonde. Unfortunately the temperature sensor broke. Back in the car I noticed that Google Maps showed slow traffic at the spot where I had been standing on the road for a few minutes. But we were the ones who had eliminated the traffic obstacle!

Such a nice lady

#3 Essen – Leverkusen-Steinbüchel
Vaisala RS41-SGP / P3020155 / 29.09.2018 1200Z
🔗 sondehub.org tinker sonde
🔗 radiosondy.info public transport

The Essen midday sonde of Saturday, 29.09.2018, P3020155, landed in a residential area in the eastern outskirts of Leverkusen. On Friday morning after, I was in Cologne for a lecture that was cancelled at short notice and decided to look for the sonde. Arrived there by bus and train, the first way led into the forest behind the property, in which I suspected the sonde. I could not see anything in the trees, and a very high and steep slope separated me from the property. So I started the way back and due to the geography I had to take a considerable detour, so some 20 minutes later I stood on the other side in front of the three terraced houses in question.

Already at the first I had success; an older lady opend me, and when I explained my concern, she asked me to the garage. The sonde was already awaiting me there. But first I was the one of interest. Whether I was a friend of the neighbor’s son to whom she wanted to give the sonde for the physics class. Why then a (designated) amateur radio operator from Gummersbach would know that a sonde had landed at her backyard. How exactly that worked. Unfortunately, the parachute hung out of reach in the first tree of the forest, the sonde was lying on her lawn and had been salvaged immediately. Very happy about the first successful cold sonde hunt I started my way back a little later.

Preparation: F

#2 Essen – Wildbergerhütte
Vaisala RS41-SGP / P2531249 / 04.10.2018 1200Z
🔗 sondehub.org in storage
🔗 radiosondy.info individual transport

I was sitting in the lab at the TH when the midday sonde P2531249 from Essen, which was supposed to land behind Siegen, did not burst high and hit Wildbergerhütte with hardly any brakes. Kai, who sat next to me, suggested to go there, and after a side trip to mine, where I quickly grabbed Macbook, SDR and Yagi, we set off. Arrived there, the disappointment followed. My Macbook had only little battery left and the prediction was very vague. I had no reception at the prediction. Kai had taken his laptop, a real hefty thing, and I had sent him my toolchain. Nothing had been installed yet. So that was done in the car.

Unfortunately SDR# was so stuttery that a decoding was not possible when we could pick up the signal a few hundred meters further. In addition, the frequency axis was somehow not right so the reception was a gamble. After half an hour searching on the meadow from where the signal came, without any real results, it became dark.

We decided to go back to the village where we could pick up the signal for the first time to make one last attempt. And indeed: a faint RS41. Don’t lose the bearing now. I held the Yagi, Kai the laptop: This is how we walked up the mountain in front of us, down the mountain again, through a forest, a steep embankment, across the road. At the end we stand at a field, it is pitch dark, and Kai is the first to see the green LED of the barometer board flashing. A meadow landing, barely audible with the big yagi from 700 m with a mountain in between. As it turned out later, the landing site was a stone’s throw away from the radiosondy prediction we hadn’t paid attention to, but some hundred meters away from the one made by wetterson.de.