[receese]

Even with a large sample, temperature and humidity data is useless unless it is ensured to be properly measured (ie outdoors, away from the person, etc). Pressure data is another story, and although it is still low quality it can be smoothed.

That's why I prefer pressureNET to opensignal. Also pressureNET is actually open source, unlike opensignal which sells all your smartphone/personal data to anyone who wants it.

[JamesCRR]

WeatherSignal is a slightly different project to OpenSignal (but it's by the same people) - we're sharing data with several academic institutions and independent researchers, and will make the feed fully open. Also NB, PressureNet is a great project, WeatherSignal also collects pressure data but I think other sensors are relevant.

We have an algorithm in WeatherSignal that tries to determine whether users are indoors or outdoors - there's a roof icon that appears or disappears, try it, it's pretty accurate during the day time.

WeatherSignal project is basically funded by OpenSignal sales, we sell to carriers and regulators -- who can act on the data to improve service.

(I'm James Robinson, a co-founder of OpenSignal/WeatherSignal)