20
Oct
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Since last night's announcement, there has been a lot of speculation surrounding the Galaxy Nexus. One of the most mysterious features of Samsung's latest Nexus device is its onboard barometer. Many have been questioning why Samsung would include a barometer in the Nexus' sleek chassis, citing possibilities from more accurate weather prediction to simple altitude detection (which is partially true).

In a Google+ post today, Android Engineer Dan Morrill gave us the scoop on what the barometer is actually for, and it's more interesting than you might think.

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Morrill explains that the barometer is actually intended to speed up GPS location, because "locking onto a GPS involves numerically solving a 4-dimensional set of linear equations - 3 dimensions in space, and time."

That sounds a bit complicated, doesn't it? Fortunately, Morrill broke it down further for readers, explaining that assisted GPS (aGPS) is popular because it gives a rough, city-level estimate of location. Including a barometer in this process speeds things up further, giving a "reasonable first-cut estimate for altitude" based on atmospheric pressure. Determining altitude quickly eliminates one of the three spatial dimensions of GPS location, and, when added to aGPS' 2-dimensional estimate, location can be determined much more efficiently.

Morrill admits that an onboard barometer could be used for weather prediction, but notes that the Galaxy Nexus' barometer may not be "weather grade."

So there you have it - there really isn't much mystery behind the barometer in the Galaxy Nexus. "It's worth noting," Morrill adds, "that the Xoom has a barometer too, so it's not a new thing."

For Morrill's full explanation, check out his post on Google+.

Liam Spradlin
Liam loves Android, design, user experience, and travel. He doesn't love ill-proportioned letter forms, advertisements made entirely of stock photography, and writing biographical snippets.

  • http://www.AndroidPolice.com Artem Russakovskii

    Had no idea this was the reason - fascinating.

  • http://electrojelly.wordpress.com Emmanuel

    Do you think what I'm thinking?
    Next year, built-in thermometer, stethoscope and sphygmomanometer (blood pressure).

    Then you know your location, you elevation, the temperature and your heart beat.

    • Ed

      Your phone already has a thermometer for the battery. A thermometer for the environment would not be accurate due to heat generated by the phone.

      • http://sketaful.se Sketaful

        Well, one thermometer that measures the heat of the phone, and one that measures the heat in the air minus the heat from the phone? :P

        • http://matjoe.com matjoe

          nice one! bring it on android 4.1

        • http://twitter.com/Neverlasting Will

          Who wants to know what temperature it is inside their house? If I'm required to leave my home to gauge the temperature, I'd just as soon pull it up from the Internet.

        • Jason

          Or, you know, not have to go through all that.

    • http://gthing.net sam
  • DingieM

    I want a tachyon/torsion field meter!

  • Mr. Mark

    i dont know why they dont just include flux capacitors.

    • Seth

      People already complain about Android battery life. 1.21 gigawatts? Great Scott!

  • Din

    Add a thermometer and make apps for weather and storm hunter on the next Samsung phone.

  • Dragonithe

    And could we also get a explanation for why they didn't include a sd slot?

    • Michael

      Lol. Perfect question. Doubt you'll get an answer.

    • Barry

      No SD slot is to tie us more fully to the cloud. In Google's world view the days of local mass storage are over and we are going to like it, whether we like it or not.

      Amazon have done the same thing with their Kindle Fire.

      It is not enough that we simply buy products - we have to "consume services" as well.

      If I were them, I'd do the same. Being as I am not, I will stick with phones with SD slots ;-)

      • http://www.asd.com pleya

        Very Nice comment!...
        I am agree: we gonna like it, whether we like it or Not!!! :)
        fking true!

    • thomas

      Becuase they didn't have room after they put in the barometer, duh!

  • Dragonithe

    Intresting reasoning behind the including of the barometer.
    But could we also get a explanation for why they didn't include a sd slot?

  • http://www.marketingcradle.com/ Jack

    Interesting .. I was wondering whether they included it in the phone by mistake .. LOL

    • http://electrojelly.wordpress.com Emmanuel

      LOL.
      Guy: "Where's our barometer?"
      Engineer: "Whoops, I forgot it in the phone"
      Guy: "Ah, I think that's ok."

  • seth

    My xoom has a barometer and it has by far the fastest GPS lock of any Android device I've had and I've had seven from stock to heavily modded.

  • Jaz

    All I know is that this phone is making me want to leave htc sense. This phone is looking awesome. I'm not due for an upgrade till june 2012 so maybe by then they will have announced the next nexus. he he

  • steve

    I think Google might be disappointed in how effective this will be in determining values for part of their location prediction equations. Small scale barometers such as this need almost constant calibration to determine altitude to any degree of accuracy, because the pressure of the air column above the phone will fluctuate based on temperature, and humidity even within an hour, let alone across days and seasons. Warmer air will rise and not weigh down on the sensor as much, creating a reading of higher than actual altitude, while colder and water-laden (clouds) air will be heavier, push down more, and give a reading of being at lower altitude than reality (the sensor will think that more air is above it pushing down, instead of just heavier air). I have had three of those triple sensor watches of different brands (the latest is a top-of-the-line Suunto ) for hiking and while the barometric pressure has been spot on, altitude is always within about 900 ft, even hours after a calibration at the same altitude. Suunto uses the best equation, but even their devices will be off (and mine is constantly), because of the climactic variability in the air column above the sensor.

    I am seriously worried about whether this device has the same GPS issue that has plagued other Samsung devices in the past, and this an attempt to help mitigate it. I hope I am wrong on this, and they are just trying to drive the triple sensor industry forward, but knowing how well even the best of these work, I can't see this being the real reason...

    • http://lavadip.com HRJ

      It may not give a very accurate altitude, but it may be enough to make a first cut guesstimate and iteratively discover a more accurate solution.

    • Hans

      There are no GPS issues with the Galaxy S2. It's locking in faster than any other mobile I've ever seen. And it keeps locked in even with extremely limited sky-view.

      • SK

        Which Galaxy S2 do you have? The one with Tmobile uses a Qualcomm chipset and those are known to have better GPS performance than whatever other chip Samsung uses in their "bad GPS" phones.

  • http://About.me/DarknesSx DarknesSx

    Cool... Android 5.0 will have a Microwave :D

    and maybe will function a vacuum cleaner!! xD

    Android for LIFE!!

    • http://ericcamil.com Eric

      I wouldn't be surprised to see us controlling more devices with Home and different wireless signals as time goes on. I don't know if we'd have a "microwave" but being able to put popcorn in the microwave and remotely turn it on so when you want it it starts isn't out of the question.

      I'm waiting for the app that syncs with the remote thermometers we use in the smoker.. so my phone can beep me when the temps are perfect.

      Android - thank God it's an open system.

      • Zac

        Didn't you watch Google I/O? They talked about Android@Home. You should look it up.

    • http://twitter.com/#!/brandonjnunn bjn714

      All Android phones already have one. It is called the cell phone radio.

      • Hans

        Radio's don't emit microwaves though.

        • Zigmar

          Really, what do they emit than? Maybe an infrared light or gamma radiation? Hint: an absolute majority of cell networks operate in UHF frequencies (at about 1000-3000 MHz), which does always falls withing definitions of microwave spectrum (roughtly 300 MHz to 300 GHz, depends on a source).

  • jon

    my xoom sucked at GPS so don't think this will help. My LG optimus is much better with GPS than my xoom was. I was using my xoom on a trip to new York and it could never keep a lock, missed an exit because of it, and would think we were miles where we were. Had to switch to using the optimus and it worked perfectly without the barometer.

  • Simon Belmont

    Well, they introduced support for a barometer in Android 2.3. So, it makes sense that Honeycomb and ICS have it.

    It also makes sense that the first Honeycomb tablet and the first ICS smartphone have a barometer on board. The reason for its use is really intriguing and cool though.

  • TBolt

    I wish they had used a 'weather grade' barometer since they were installing one anyway. Oh well.

  • http://electrojelly.wordpress.com Emmanuel

    Here's my question. By knowing how long the signal travels to the GPS satellites, how far they are stationed, and how long it takes light to travel, couldn't you figure out your elevation?

    • Mattchew

      Yes, but if you already have an idea of your elevation the math is much simpler.