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Altimeter issues. Reset/Calibration possible?

Sam

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Perth is -30m, I learn. Doesnt really bother me.

I had assumed this would be a GPS thing... achieved by overlaying the car's location over a map. Surprised if it's barometric/ pressure based.

To test, I will be hoisting my Grenadier in the sky 50m with a crane... or driving up a multi-storey car park, and will provide readings
 

ECrider

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While I'm in pedantic mode should it not be referred to as 'Elevation', except that one time you hoist it by a crane then guess it would be correct.

Jeez I must get a coffee....
 

Psignore00

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For those that are upset/complaining/disenfranchised by the “altimeter,” what exactly do you expect from it?
Something that worked. What’s the point of having this if it’s so inaccurate it’s worthless?

I don’t need an altimeter, but if the vehicle has one, it should have a purpose, what’s the purpose of something who’s margin or error is so large the data doesn’t mean anything?

I’d rather it not even be there if it’s going to tell me I’m driving 85 feet below sea level.

My dealer told me the same thing about 75ft variance and that it might take some time to “break-in”, so I’m going to keep recording the shots that have to be outside that variance -85 to -100 and if it’s still happening when I go get my hitch, will address it then.
 

GrumpyBastard

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This is not meant to be rude or snarky, just a dose of reality.

For an “altimeter” to “work,” it needs to be constantly updated with an accurate local pressure setting. It’s far from a set it and forget it kind of instrument. Over the course of a few hours of flying wildly different altimeter settings are encountered due to movement of and through various air masses. Caveat: this is all assuming that you’re intending to display True Altitude, aka MSL. Flying Texan will chime in about pressure altitude I’m sure.

There seems to be some misconception that an “altimeter” on some way cross-references DTED map data for elevation and knows exactly where you are in height above sea level to the foot. That’s just not true. An altimeter, in its true form, simply measures pressure difference from a standard datum plane.

I highly doubt that if Ineos would have put a real altimeter in the Gren anybody, pilot nerds excluded, would even take the time to set the pressure. Likely, more would complain about it.

Rather, maybe they should have called it something other than an altimeter, as that name implies that it is indeed such an instrument.

Now let’s get back to the real issue: the digital and analog compass don’t agree!!
 

reauxheaux

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This is not meant to be rude or snarky, just a dose of reality.

For an “altimeter” to “work,” it needs to be constantly updated with an accurate local pressure setting. It’s far from a set it and forget it kind of instrument. Over the course of a few hours of flying wildly different altimeter settings are encountered due to movement of and through various air masses. Caveat: this is all assuming that you’re intending to display True Altitude, aka MSL. Flying Texan will chime in about pressure altitude I’m sure.

There seems to be some misconception that an “altimeter” on some way cross-references DTED map data for elevation and knows exactly where you are in height above sea level to the foot. That’s just not true. An altimeter, in its true form, simply measures pressure difference from a standard datum plane.

I highly doubt that if Ineos would have put a real altimeter in the Gren anybody, pilot nerds excluded, would even take the time to set the pressure. Likely, more would complain about it.

Rather, maybe they should have called it something other than an altimeter, as that name implies that it is indeed such an instrument.

Now let’s get back to the real issue: the digital and analog compass don’t agree!!
I have multiple devices that transmit altitude. One being a Garmin GPS from 25 years ago.

It's a cute little thing, but utterly useless and should have been cut if they couldn't figure out how to prevent this amount of error in reading. I don't think anyone is expecting to level acreage with the altimeter, but it looks stupid at this point especially when other methods are available.

Hell, add a line of code that says.
IF ALT <0, ALT=0
 

Krabby

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It comes on the TM but I'm hoping some cool replacement thing finds its way to the aftermarket. Not sure what - just something either more useful or more beautiful - something from Smiths would be doubly cool.
 

carlg007

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I have multiple devices that transmit altitude. One being a Garmin GPS from 25 years ago.

It's a cute little thing, but utterly useless and should have been cut if they couldn't figure out how to prevent this amount of error in reading. I don't think anyone is expecting to level acreage with the altimeter, but it looks stupid at this point especially when other methods are available.

Hell, add a line of code that says.
IF ALT <0, ALT=0
Exactly! Well said! If it can not work correctly what is the point! I would have saved my money, it just looks stupid.
 

donnygreygrenadier

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reauxheaux

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Sounds like we need a lowest altitude brag thread. Currently in traffic at -111.
20240131_165602.jpg
 

Clark Kent

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l like the altimeter, and
  • as soon as I saw I was driving 10m below sea level, I knew it was a barometric altimeter
  • and, anyway, my Grenadier can drive 80m below sea level
Or was it 80 cm? :unsure:
I suspect the compass and altitude information is repeated from the onboard GPS used by the Pathfinder system. If that's correct, then the altitude (elevation actually) is GPS-derived via satellite signal timing and triangulation. My compass regularly freezes. When that occurs the altitude data also freezes which suggests it's GPS-derived. I think this has been acknowledged as a software issue.

Be interesting to look at the back of the compass to see if it has a vent or static port which could be a baro pressure source. If it's a sealed unit then I'm leaning towards GPS data.
 
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nuclearbeef

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1706742378042.png



These are the current barometric pressure readings for the US.
The Gren altimeter should read about 400 ft low in St Louis and approximately 250 ft high in Seattle right now.
 
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