Some more notes about our floating buoy project:
Two yerar ago we started to deal with amateur, pico (floating) ballooning. In the last summer we decided to collect some practices arund the larger amateur balloons, carriing camera, and we interested specially the recovery processes.
We concluded, there are everyday event the meteo sonda/balloon flights, we need only follow them and start to find each of them. In half a year we collected significant amount of them, different modells, mainly produced by finnish company, Vaisala. It become clear, the latest model, RS41 is a very good, sophysticated design, has good quality GPS modul, and recent digital radio chip from SiliconLabs. This devices developed one-flight-only, dont want to recover them. During the flight they transmit the sensors data on the dedicated frequency for meteorological measures, on 400-405 MHz. We found, some polish developers started to reprogram this devices, to use 430 MHz ISM band and radio amateur frequency.
The program was modyfied by a member of our the team, here is a description from it:
O M 3 B C → in the manu My projects, and the last item in the list:
Recycling of Vaisala RS-41 meteorological sonde
This device is ready-to-use as amateur balloon paylod too. But it 4 x times heavier, as the amateur payloads, flying on pico balloons. Consequently to fly need larger balloon, more helium, and more money… we decided to search another way to use this devices. In our capital city flowing through the Danube river, we decided to put on the water this telemetry devices. On the riverside located our technical university, BME, with the building, top of it our satellite ground station. The main antenna is a 4 m parabola, was ready in springtime. We decided, to test its remote-control mode try to foloow our floating bouy in the city. For this purposes was developed a small rtty decoder program running on RPi, and produce and upload the coordinates of the buoy to the ground station,s control unit.
http://gnd.bme.hu/ham.php
http://152.66.73.241:33333/
The river in the city is 3-400 m wide, but has in the center heavy ship-traffics, and of course, the path of the buoy infulenced with wind in different directions. To study the real path, we started some test buoys… We put the real experiment with the telemetry payload into the middle of the river, and we followed it on public transport on the riverside. At the south bridge there are some ships fixed to the strand. Edge of this objects, cumulated some garbadge, mainly trees, floating on the water. On this small dump stopped our buoy, become horizontally, laying on this garbadge. We get help from the people on the ship to free it, but this small time was enough to go into some water on a small hole, which on the floating wasnot in the water. The electronic stopped to transmit anymore.
It continues the trip more 6-7 km, and finally after the city boarder, on a private territory on the water company, a man found it on the riverside. Inside was a message, and he sent me a mail, and we got back the device. It was intresting to investigate the demages on the electronics, because the relative short time was cover with water.
All the trip was 15 km long, in half path we had the possibilities to receive the telemetry ftom it, so it was successfull experiment.
We collected some nice idea, to improove the design, to use more effects, to able follow it in visible, maybe with online webcams, or produce active light effects, and so. We plan some more start too, but in summertimes the reiver is “very busy” with different public, sports, turist events.
In this moment, I dont know what will be a “real situation”, when this or similar devices and setup become practically usefull or helpfull, but it seems, it would be good to invetigate the possibilities.
Thank you for the increadible possibilities to route a local data-transmission event to world-wide accessible…
t.janos
