Vista Satellite altitude vs. barometric readings

[+Alan2]

Which do you use? Post examples for each that you use and/or favor and why?.

[+apersson850]

I'm often interested in the altitude profile, total climb and such figures, and that works with the barometric altitude only. So, there is no real choice, yet...

 

Anders

[Kerry.]

Rebate??? huumm bit of a miss worded option really as some might not think they use it (or need it, or want it) but wanting a rebate on GPS altitude, well that's really a bit of a wasted cause.

 

Cheers, Kerry.

 

I never get lost everybody keeps telling me where to go

[Kerry.]

Rebate??? huumm bit of a miss worded option really as some might not think they use it (or need it, or want it) but wanting a rebate on GPS altitude, well that's really a bit of a wasted cause.

 

Cheers, Kerry.

 

I never get lost everybody keeps telling me where to go

[DARC]

The baro altitude requires calibration of factors that I usually don't know at the time when I discover a need to calibrate the baro.

 

It would be a lot easier if the baro used the sat altitude to get a reference or to do initial calibrations.

 

It is because of the baro calibration issues that I always save the Active Tracklog which happens to retain the sat generated altitude fix.

[+st_richardson]

I don't really use the altitude except to show others how steep the hill was that I climbed. If I zoom the ranges just right, I can make a mole hill look like a mountain.

[+st_richardson]

I don't really use the altitude except to show others how steep the hill was that I climbed. If I zoom the ranges just right, I can make a mole hill look like a mountain.

[jfitzpat]

quote:

---

Originally posted by DARC:

 

It would be a lot easier if the baro used the sat altitude to get a reference or to do initial calibrations.

 

---

 

FWIW, on my Vista, if you select Calibrate one of your options is to calibrate from GPS elevation.

 

-jjf

[Atilla the Pun]

Why is HDOP greater than VDOP?

 

AtP

[Kerry.]

quote:

---

Originally posted by Atilla the Pun:

Why is HDOP greater than VDOP?

 

AtP

---

 

You might be getting the DOP's mixed up HDOP is the lowest order DOP

 

For any given day the general order from bottom to top goes something like

 

HDOP < VDOP < PDOP < GDOP and TDOP floats between HDOP & VDOP and can be <= HDOP.

 

Cheers, Kerry.

 

I never get lost everybody keeps telling me where to go

[Kerry.]

quote:

---

Originally posted by Atilla the Pun:

Why is HDOP greater than VDOP?

 

AtP

---

 

You might be getting the DOP's mixed up HDOP is the lowest order DOP

 

For any given day the general order from bottom to top goes something like

 

HDOP < VDOP < PDOP < GDOP and TDOP floats between HDOP & VDOP and can be <= HDOP.

 

Cheers, Kerry.

 

I never get lost everybody keeps telling me where to go

[+Alan2]

I recorded my flight from Florida to New York. Visually I could see actual altitude on the Vista when looking at the satellite generated altitude ( 32,200 max) but the track log recorded cabin "barometric" pressure which peaked at about 6400 feet which might tell you why your ears are getting clogged but are useless otherwise.

 

It would have ben interesting to try to set the barometer to the sat generated altitude about half way up to see how it tracked afterwards; if it matched actual altitude.

 

Ok, here's your assignment if you choose to accept. Next person planning a plane trip, try the experiment of setting the barometric from the sats and report back if it then tracks OK.

 

Tks

 

Alan

[+fizzymagic]

quote:

---

Ok, here's your assignment if you choose to accept. Next person planning a plane trip, try the experiment of setting the barometric from the sats and report back if it then tracks OK.

---

 

It won't. The cabin is pressurized, but the pressure differential between the outside and the inside does not remain constant. Even if it did, the barometric pressure still wouldn't track the altitude, as atmospheric pressure is a nonlinear function of altitude. Zeroing a barometric altimeter is not simply a matter of introducing an offset.

[+apersson850]

I've tried, and when you are high enough, it doesn't work at all. The calibration will not accept an altitude of perhaps 10500 meters, when the pressure is equivalent to 2000 meters.