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The Galaxy S4 has a Barometer
- dan1234 14y agoA Barometer is present on a few other Androids, so I assume it comes free as part of another chip. It's rarely listed as a feature though, which makes me think it's only enabled because it's there. Has anyone checked the calibration/reliability to see if it's actually worth using?
- dbaupp 14y agoQuite a while ago, I remember seeing an article on HN about Google encouraging new Android phones to have barometers, and some reasons for it (possibly something to do with faster/more accurate GPS fixes).
- voltagex_ 14y agoThat's correct. As I understand it, you can get a reasonable altitude estimation from the barometer. I'm pretty sure it was in the S3 as well.
- mattstreet 14y agoYep, and the Nexus 4 has it too.
- criley 14y agoA barometer is present in new smartphones as a part of the GPS because GPS only provides accurate X/Y positioning, and using barometric data (which varies predictably as elevation changes) allows the GPS to have Z data as well, giving it a better representation of your location. (This is the best explanation I've seen, please correct me if I'm wrong). If you want to donate your barometric data for study, I recommend checking out PressureNet https://play.google.com/store/apps/details?id=ca.cumulonimbus.barometernetwork&hl=en https://play.google.com/store/apps/details?id=ca.cumulonimbu... The PressureNet dev(s) are active on HackerNews and have made a couple of posts about the app. For the record, my Galaxy Note II has a barometer as does the Galaxy S3 -- meaning the S4 didn't change anything in this regard!
- cjg_ 14y agoGPS provides accurate 3D positions. However if you know roughly your position the GPS fix can be acquired more quickly. So the barometer only helps you with an estimate Z pos, which helps you get the GPS fix faster.
- diroussel 14y agoIf you have line-of-sight to only three GPS satellites then you don't have enough information to compute your altitude [1]. If you can see four satelites, the altitude can be computed. edit: spelling [1] http://gis.stackexchange.com/questions/12866/why-does-gps-positioning-require-four-satellites http://gis.stackexchange.com/questions/12866/why-does-gps-po...
- archivator 14y agoJust tried it out and my phone doesn't report any position (however inaccurate) if it's only seeing 3 satellites. Also, although it's possible in principle, I doubt the timing information on a consumer phone is accurate enough to get a possible fix from 3 data points.
- cjg_ 14y agoAh, yes of course :)
- StavrosK 14y agoIf you have line-of-sight to three GPS satellites, you can compute all three of your coordinates (one will be impossible and can be ruled out), assuming you have an atomic clock locally. If you're like most of us and don't, then you need a fourth (and fifth, and sixth, and seventh) satellite for timing adjustments. Until then, you'll get no fix.
- Retric 14y agoYou don't need a local atomic clock for fairly accurate positioning using 3 satellites it just takes longer. Basically, what you need to know is distance from each satellite and an atomic clock let's you find that directly. However, GPS satellites are moving so much faster than you that at over time you narrow down the possible distances involved fairly quickly. Though this does take a lot of processing and is not on any consumer device I know of. Also of note, phones get a reasonable fix using base towers which can speed up GPS calculations though I don't know of any phone that does this.
- lucb1e 14y agoDidn't the S3 already have this, or does only my Note II? I've always wondered what it was for (GPS apparently, says another comment here).
- andrewaylett 14y agoYes, the S3 has one too.
- deleted 14y ago[deleted]
- micampe 14y agoThe article is one single quick paragraph, take a look at it.
- deleted 14y ago[deleted]
- Tyrannosaurs 14y agoWhile direct, immediate benefit to the user seems limited, there are some interesting possibilities with this. Weather forecasts made up from thousands of highly localised data points? That feels like something Google would want to be involved in - a highly data centric way of improving something we already do which is of interest to many people. Depends on accuracy obviously but maybe in the future.
- jbuzbee 14y agoMore interesting than the barometer is the thermometer in the S4. Has any other phone included one yet? Crowd-sourcing of weather data is an interesting concept, but I wonder how useful a thermometer will be when phones will most often be in pockets, indoors, in a car, etc.
- danshapiro 14y agoMany android phones have a thermometer. It precisely measures the weighted average of the ambient temperature and the waste heat from the processor. In other words, just this side of useless, because the thermometer is next to a heater.
- jeza 14y agoNot very useful at all. To accurately measure temperature you really need a Stevenson screen (http://en.wikipedia.org/wiki/Stevenson_screen http://en.wikipedia.org/wiki/Stevenson_screen). But furthermore, this needs to be located in a good location with attributes such as good air circulation, lack of buildings, concrete, trees, etc. It's often impossible to meet all these conditions in an urban area, which means you're really measuring a micro climate. While there are some sites that crowd-source data from personal weather stations, there's really no guarantee that people have followed good guide lines with the placement and installation of their weather station. It's sometimes obvious when this is occurring because you see some pretty large variations in temperature in more or less the same neighbourhood.
- kybernetyk 14y agoBut what if many people measure their local microclimates? Couldn't one 'add up' all those measurements to get the 'real' temperature out of it? Would be like a high resolution heat map.
- calinet6 14y agoMost new-ish Android phones have a barometer. It assists in determining a rough altitude to make GPS lock faster. Hence the ability to use apps like this to track barometric pressure across smartphones and track trends: https://play.google.com/store/apps/details?id=ca.cumulonimbus.barometernetwork&hl=en https://play.google.com/store/apps/details?id=ca.cumulonimbu...
- KaeseEs 14y agoI'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 14y agoSomebody posted a link to pressureNETs data: https://news.ycombinator.com/item?id=5380672 https://news.ycombinator.com/item?id=5380672 http://pndv.cumulonimbus.ca/ 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.
- trendspotter 14y agoSorry, this is nothing new at all. Here is a list of smartphones which have a build-in barometer sensor to measure atmospheric pressure to improve the location services: Google Nexus 4, Samsung Ativ S i8750, Samsung Galaxy Nexus i9250, Samsung Galaxy S3 i9300, Samsung Galaxy S3 LTE i9305, Samsung Galaxy Note (N7000), Samsung Galaxy Note 2 (N7100), Simvalley Mobile XT-710 Apogee, Takwak tw700.
- manojlds 14y agoDid you read the article? It says so too. You are sorry that you just read the title?
- jusben1369 14y agoDoes this help running/cycling apps where folks want to measure altitude gains more efficiently?
- joonix 14y agoHad no idea my Note II had a barometer. Just got pressureNET.
- lambersley 14y ago+1
- lucb1e 14y agoI knew; I just didn't know what to do with it.
- klinquist 14y agoI've had fun with the barometer in my Nexus 4 - with the app 'Sensitive Altimeter' ... on flights I can see at what elevation the cabin is pressurized to :).
- huherto 14y agoI suppose now there is going to be an app to measure the height of a building. http://www.snopes.com/college/exam/barometer.asp http://www.snopes.com/college/exam/barometer.asp
- 37prime 14y agoDoes Galaxy S4 have a kitchen sink?
- ChuckMcM 14y agoThe coolest thing about the barometer foe me, is that you can do interesting pedometer + altitude change sorts of apps. Walking 10,000 steps with 2,000' change in elevation is a lot more calories than 10,000 steps with 0 change in elevation :-)