Show HN: pressureNET 3.1, now with more weather | Hacker News Reader

Show HN: pressureNET 3.1, now with more weather

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10 pointscryptoz8 comments

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...

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

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.

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.

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?

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!

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?

Right on, thanks for running pressureNET! We updated this release with some new features that hopefully will be useful to you. I don't think your alpha apk will automatically update since it didn't go through the Play Store. You shouldn't have to uninstall first, but if you go to the Play page you should be able to install the update right over it.

Thank you very much for your help!

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.

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