

Show HN: pressureNET 3.1, now with more weather - cryptoz
http://play.google.com/store/apps/details?id=ca.cumulonimbus.barometernetwork&3.1monday

======
cryptoz
We just launched pressureNET 3.1 this weekend and started crowdsourcing
weather conditions along with the atmospheric pressure measurements we were
already collecting. We're seeing 10,000 barometer measurements per hour, and
about 1 weather condition per minute.

Here's our launch blog post: [http://www.cumulonimbus.ca/announcing-
pressurenet-3-1-now-wi...](http://www.cumulonimbus.ca/announcing-
pressurenet-3-1-now-with-more-weather/)

Our plan is to dramatically increase the data inputs to existing weather
models, as well as try building entirely new systems of weather forecasting.
We're going to have a really incredible ability to predict thunderstorm
formation with our high resolution view on atmospheric pressure.

We have a live data visualization / graphing tool on our main pressureNET site
at <http://pressurenet.cumulonimbus.ca>

------
xur17
I've been wondering this since last time I saw your app, but I wasn't sure how
to ask it:

If I understand correctly, you use barometric pressure reported by peoples'
phones to attempt to predict weather. This makes sense to me. How do you
handle changes in barometric pressure due to changes in altitude. If I work in
a tall office building, wouldn't the app see a change in barometric pressure
when I go up the elevator? Is this small enough that it doesn't matter, or do
you handle it in some way?

Anyway, the app looks great - I think I'll install it again to play around
with. Keep up the good work.

~~~
cryptoz
Thanks for your comment!

> How do you handle changes in barometric pressure due to changes in altitude.
> If I work in a tall office building, wouldn't the app see a change in
> barometric pressure when I go up the elevator? Is this small enough that it
> doesn't matter, or do you handle it in some way?

These are excellent questions. The data is extremely noisy due to exactly the
reasons you suggest. At near-sea-level, an 8 meter altitude change results in
a 1mbar change. So the effect is very significant and causes noise. There are
some simple methods to weed out the noise: some changes are obviously too fast
to be meteorological in nature, so those can be discarded.

Cumulonimbus itself is not working to solve this problem right now, but Cliff
Mass and his lab are. We've livestreaming our data to them and they are
currently working on quality control algorithms. They are starting by looking
for phones that aren't moving, using the GPS and accuracy information. From
there they will work on assimilation and then begin forecasting.

Quality control and altitude correction is indeed important for our data to be
properly used in meteorological systems, but currently we're seeing a simpler
way to do quick analysis. The density of the network is getting pretty good in
cities (though we're seriously lacking in more rural areas and we'll have to
pick that up), which means that single data-point altitude changes are very
obvious compared to the rest of the nearby points.

~~~
xur17
Thanks for the fast response! It's pretty amazing to see the map, and see how
many people are contributing data to this.

In terms of the data that is submitted:

1) Is my location data submitted, and if so, how accurate is it?

2) Is this data anonymized in some way (are all contributions linked to a
single person - because this would basically give you my location data)?

3) The public sharing option is a little bit confusing - does this share with
PressureNET, researchers, and forecasters in addition to the public?

~~~
cryptoz
1) Yes, your location is submitted. We just started collecting location
accuracy information with this release a couple of days ago. So I'm not sure
yet exactly how accurate this is, but we'll be learning about that in the
coming days and weeks.

2) For the map view in the app and for our public site, yes the data is
anonymized. However, we do keep a unique ID in the database. This is required
in order to calibrate the sensors, filter out noise and have good quality
control.

3) I forgot to add better descriptions / Help screen to this update. Sorry
about the confusion. The Public option is not in use yet, but will be soon
when we finish our livestream API. The idea is that yes, the data will then be
available to us at Cumulonimbus, to researchers and forecasters, and also to
the public at large. For the Public API, we do plan to anonymize the data but
we haven't decided exactly how yet (hence it's not available yet).

Thanks for your questions!

------
criley
I keep pressureNET running in the background on my phone. I don't get much use
out of the app itself -- barometric pressures on a map aren't that useful to
me, but I like contributing to the project.

I worked with the developer(s) on previous releases with custom builds and I
can confirm that battery life is very respectable and that this app does not
consume crazy resources. On my Galaxy Note II w/ Android 4.1.*, when my screen
gobbles about 30% of my battery, pressureNET sits around 2%.

Question for the developer: Will my alpha .apk distributed to me via email
automatically update to 3.1+, or do I need to remove it and jump back into the
official release channel?

~~~
sc0rb
Maybe you live in a bubble where you never book alirline tickets and medical
insurance, then use those airline tickets to go abroad and then use the
medical insurance when you hurt yourself.. You are the sterotype american
silicon valley bubble boy.

