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Near Space Balloon data recorder - Printable Version

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Near Space Balloon data recorder - David Voit - 08-12-2019

I am organizing a near space balloon launch with the local science museum and the amateur radio community as a STEM project.  I am trying to sort out how much data can be recorded on a cell phone and to see if it fits the five to 6 hour duration of such a flight.  Can the phone be programmed to transfer data during the flight to a computer/transceiver for real time monitoring?  If there is a page with the specifications for the software, please let me know.  I am running an experiment at 1 hz to see what happens.  It will probably work great but I completely new at this.

For information, a small helium filled balloon carrying a payload of about 4 pounds will rise to about 80,000 feet and burst.  The payload comes down by parachute.  The balloon is tracked with GPS through the APRS system.  This type of project has been going on for over 20 years so there is a lot of experience out there but nobody seems to have used a cell phone.

David Voit


RE: Near Space Balloon data recorder - Sebastian Staacks - 08-14-2019

This sounds exciting Smile
In principal, phyphox is (not yet) well suited for long-term measurements, because the screen needs to stay active and because phyphox may simply crash if it runs out of memory. However, when you only record at a rate of 1 Hz, you should be fine for quite a long time and you could do several hours even at a higher rate with a decent phone. Testing it a few time, as you say, is certainly the best idea to make sure that it works as expected.

To monitor the phone during the flight, you can use our remote access feature. The documentation is a bit lengthy (https://phyphox.org/remote-control/), but in practice it not that complicated. However, you need a wifi connection for this and I doubt that it will reach to 80,000 feet. Also, you should keep in mind that at 80,000 feet there might be quite a few environmental conditions that are way outside the ranges of what is "normal" for a phone. So, I am not entirely sure if everything will continue to just work up there...

In any case, I would love to here how this goes for you!


RE: Near Space Balloon data recorder - Roland Van Kerschaver - 08-14-2019

https://www.thepocketlab.com/educators/forum/pocketlab-frequently-asked-questions


RE: Near Space Balloon data recorder - David Voit - 08-14-2019

(08-14-2019, 01:00 PM)Sebastian Staacks Wrote: This sounds exciting Smile
In principal, phyphox is (not yet) well suited for long-term measurements, because the screen needs to stay active and because phyphox may simply crash if it runs out of memory. However, when you only record at a rate of 1 Hz, you should be fine for quite a long time and you could do several hours even at a higher rate with a decent phone. Testing it a few time, as you say, is certainly the best idea to make sure that it works as expected.

To monitor the phone during the flight, you can use our remote access feature. The documentation is a bit lengthy (https://phyphox.org/remote-control/), but in practice it not that complicated. However, you need a wifi connection for this and I doubt that it will reach to 80,000 feet. Also, you should keep in mind that at 80,000 feet there might be quite a few environmental conditions that are way outside the ranges of what is "normal" for a phone. So, I am not entirely sure if everything will continue to just work up there...

In any case, I would love to here how this goes for you!

I have run two phones for about 8 hours and recorded something like 25,000 data points even on my old phone.  I see the duration of the experiment can be set although I have not tried to do that.  Flights are supposed to last between 4 and 8 hours so there seems to be sufficient memory space. The duration is a result of lift and balloon size as that controls the burst altitude. The phone could easily be encapsulated in styrofoam and it might keep itself warm.  The thin air is a poor conductor of heat and there might be a cooling problem as reported from another group that sent up video equipment.  This remains an experiment that will have to be run.  I am expecting to be able to make the first flight next month.

Cell phones cannot be turned on during a flight in the US but wifi or bluetooth seem like a reasonable way to move data to a transmitter for download.  I do not expect to reach ground receivers with wifi.  What I expect is to track with the APRS system (amateur radio stuff) and then download it with one of several communication programs already in existence.  There is so much to learn and I am just getting a team together to see what we can do.  I will post progress or results when we have them.