[KaeseEs]

I'm interested in what the accuracy, stability and precision of this barometer are. For the use case that they were put into that phone (and the price point it implies), I am unsure whether data reported from these phones will be useful for PressureNet.

Longer explanation: in the parlance used for pressure measurement, a barometer is a low-pressure absolute gauge (although what they pack in the phone is a sensor or transducer rather than a full gauge for obvious reasons). In order to measure absolute pressure, it needs to pack a good source of vacuum to be used as one of the differential inputs. And it needs to do it real small and real cheap. I suspect they're using a piezoresistive or capacitative sensor for this pressure range, which both have a significant tempco, and they almost certainly can't do a valid temp-comp on the part for cost reasons (you can sort of bullshit it by characterizing the lead unit and applying that to everything based on a curve fit, but the results are not great).

Sensors in this form factor and for this price point might be accurate to within +- 2.5%, which is not terribly useful for a barometer for weather purposes.

[maxerickson]

Somebody posted a link to pressureNETs data:

https://news.ycombinator.com/item?id=5380672 http://pndv.cumulonimbus.ca/

If you zoom in on a location that has lots of people (say, New York City), you can see the readings moving together. That suggests some utility.