Altimeters on a cellphone? watch?

[Homeslice]

Anyone know about altimeters? What is the most accurate way to calculate it ---- using GPS, or by measuring the atmospheric pressure?

And I know lots of watches have an altimeter, and of course GPS devices can do it, but are there any cellphones that have it?

[Dave]

probably gps or find a survey point. the barometric pressure can work but you need to know the density altitude. if you are near a small airport the local FBO could help you out

[bmblebee]

most altimeters are barometers that measure atmospheric pressure...and changes in weather can make you think you are higher/lower than you really are.

Take a look at this watch...

Casio (PAG50-1V) Pathfinder Triple Sensor Tough Solar Watch

iPhone 3G has GPS hardware built in, so it will support altimeter applications...like this one...

www.apptism.com/apps/altimeter

[Rider]

You need to receive 4 satellite to get altitude. GPS is the only accurate way. Barometric pressure varies by the air temperature. It will get you close, but not as close as GPS. I don't know of any phones that give you altitude, but if that's what you want, get a cheap handheld GPS for under a $100.

[Particle Man]

I think I read somewhere that there's an app being developed for the iPhone... not sure how accurate it would be

[Rider]

I think I read somewhere that there's an app being developed for the iPhone... not sure how accurate it would be

You cant just have an app. You need the correct hardware built into the IPone to receive the data.. ie GPS receiver.

[Krabill]

Actually, barometric pressure is more accurate than gps for elevation measurements. You need to know what the local baro pressure is when you're taking a reading, but it is definately more accurate. A typical gps can only get you within a few hundred feet accuracy for elevation. A barometer type device will be dead nuts.

Some gps's (like the Garmin Csx60) have a barometric altimeter included. You still have to manually input your local pressure, but it has one.

[Krabill]

There's also this option - http://www.thealtimeterstore.com/watch.html?gclid=CKqM4tji_JcCFSJIagod-Wc-Cg

[Rider]

Actually, barometric pressure is more accurate than gps for elevation measurements. You need to know what the local baro pressure is when you're taking a reading, but it is definately more accurate. A typical gps can only get you within a few hundred feet accuracy for elevation. A barometer type device will be dead nuts.

Some gps's (like the Garmin Csx60) have a barometric altimeter included. You still have to manually input your local pressure, but it has one.

Bullshit. I work in the aerospace navigation industry and I can tell you GPS is dead nuts accurate. It has to be. I see aircraft do Cat III precison approaches using GPS. That is a full autopilot landing so your altitude must be dead on or you die.

[Homeslice]

Well I don't want to input the local pressure every time I want a reading........Would you have to do that every day? Screw that, I guess GPS is it then.

[Particle Man]

You cant just have an app. You need the correct hardware built into the IPone to receive the data.. ie GPS receiver.

the iPhone does have a GPS receiver...

[Rider]

the iPhone does have a GPS receiver...

I don't have an IPhone. That's pretty cool. I'd go that route then. :dthumb: No need to buy a separate GPS reciever.

[Particle Man]

so here's the 1 million dollar question: why?

:)

[Homeslice]

Cuz I'm just a data freak. I think it'd be cool to check the altitude wherever I am, even riding up an elevator or biking up a mountain.

That's another question, how often do they re-calculate the altitude? Hopefully it's not just a once every 60 seconds kind of deal.

[Krabill]

Bullshit. I work in the aerospace navigation industry and I can tell you GPS is dead nuts accurate. It has to be. I see aircraft do Cat III precison approaches using GPS. That is a full autopilot landing so your altitude must be dead on or you die.

An IFR approved gps is dead nuts accurate. Any over the counter handheld unit and/or cell phone gps device is not anywhere near as accurate as an IFR certified gps receiver in altitude.

btw - my plane has 3 gps units in it and none of them are as accurate as the old steam gauge altimeter in the panel. Why? None of them are approach certified.

[Particle Man]

Cuz I'm just a data freak. I think it'd be cool to check the altitude wherever I am, even riding up an elevator or biking up a mountain.
just wanted to make sure you weren't the one flying the next shuttle mission or anything :lol:

[Trip]

A lot of new smartphones have built in gps receivers, so I am sure there could be options for getting altimeters on a lot of them.

iphone and the blackberry storm are two that do have gps receivers, I will check my storm to see if the garmin program provides an altimeter or if my weatherbug program does.

[Trip]

The blackberry storm will report elevation in an app called Blackstar. Apparently there is a bug that inverses the number, but it is still giving you an accrurate number, just with a - sign on the front.

[Particle Man]

The blackberry storm will report elevation in an app called Blackstar. Apparently there is a bug that inverses the number, but it is still giving you an accrurate number, just with a - sign on the front.
so before I board a plane again I'll make sure to ask the pilot if he/she is aware of that :lol:

[Homeslice]

Hmm, this looks cool....

[Trip]

so before I board a plane again I'll make sure to ask the pilot if he/she is aware of that :lol:

they are trying to find it, they multiplied by -1 somewhere in the app.

[Particle Man]

Hmm, this looks cool....

sure, until the guy is paste at the bottom.

All that will be left is a mangled frame and a watch.

[Amorok]

I'm a former GCS technician for the Air Force and I can tell you that gps is pretty accurate, and a static air system can be more accurate. However, for your purposes a gps unit will be much more practical. While a pitot/static pressure system is the most accurate you can get for reading altitude, airspeed and vertical movement, the lines, probes and sensors in the plane that makes the reading of barometric inputs possible can't be duplicated in any small, handheld unit with the same level of accuracy. Thus, unless you want to get a plane and use its instruments, you're better off with a decent gps. Your iPhone will be ok for gee-whiz, but in desperate times realize it will be a few feet to a few hundred feet off, and you'll have no way to figure the error.

[Particle Man]

Your iPhone will be ok for gee-whiz, but in desperate times realize it will be a few feet to a few hundred feet off, and you'll have no way to figure the error.

sure you will... if you go splat, it was off...

[Amorok]

sure you will... if you go splat, it was off...

True, but some of us would prefer to know ahead of time. We don't all have floaty stuff around our heads as a cushion.

[Particle Man]

True, but some of us would prefer to know ahead of time. We don't all have floaty stuff around our heads as a cushion.

it's a gift. :)