How come GPS reads different

"Tauno Voipio" wrote in message

Yes - it's called the reference ellipsoid. There are actually
several of them and some GPS receivers allow selecting your
favorite one.

Interesting.

Actually, if Earth would disappear with all its mass, GPS would
get unusable, as the satellites would continue out of their
tracks due to the lack of gravity pull.

Yeah, but they'd work longer than a pressure altimeter so I think we should
still adopt GPS altimeters in case this ever actually happens.

--
Jim Fisher

Jim Fisher wrote:
"Tauno Voipio" wrote in message


Actually, if Earth would disappear with all its mass, GPS would
get unusable, as the satellites would continue out of their
tracks due to the lack of gravity pull.

Yeah, but they'd work longer than a pressure altimeter so I think we should
still adopt GPS altimeters in case this ever actually happens.

Good idea! It's always smart to be prepared. I always carry a
towel with me whenever I fly. Just in case.

John Galban=====N4BQ (PA28-180)

"Tauno Voipio" wrote in message

Yes - it's called the reference ellipsoid. There are actually
several of them and some GPS receivers allow selecting your
favorite one.

Interesting.

Actually, if Earth would disappear with all its mass, GPS would
get unusable, as the satellites would continue out of their
tracks due to the lack of gravity pull.

Yeah, but they'd work longer than a pressure altimeter so I think we should
still adopt GPS altimeters in case this ever actually happens.

--
Jim Fisher

Hmmm, and what alti do you think to meter without an earth?
I would be more worried about avoiding the big yellow things that are
the cause of all this, if it happens.

-Kees

I would be more worried about avoiding the big yellow things that are
the cause of all this, if it happens.


and about the poetry...

--
Thomas Borchert (EDDH)

On Sun, 12 Jun 2005 10:14:33 -0500, "Jim Fisher"
wrote:

So, for safety reasons, I think we should all use GPS altitude so that we
can all safely land if the Earth ever actually disappears.

Hmmm. Where would you land?


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

"Ron Rosenfeld" wrote in message
...
On Sun, 12 Jun 2005 10:14:33 -0500, "Jim Fisher"
wrote:

So, for safety reasons, I think we should all use GPS altitude so that we
can all safely land if the Earth ever actually disappears.

Hmmm. Where would you land?


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

In the parking lot for the Restaurant At The End Of the Galaxy, or was
that Universe?

"Casey Wilson" N2310D @ gmail.com wrote in message
news:6u6re.5344$2K4.62@trnddc08...

"Ron Rosenfeld" wrote in message
...
On Sun, 12 Jun 2005 10:14:33 -0500, "Jim Fisher"
wrote:

So, for safety reasons, I think we should all use GPS altitude so that
we
can all safely land if the Earth ever actually disappears.

Hmmm. Where would you land?


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

In the parking lot for the Restaurant At The End Of the Galaxy, or was
that Universe?

That was universe. Don't remember if hamburger prices were given.

AIM 1-1-19(a)(8) tells pilots not to use GPS altitude: "GPS altitude should
not be relied upon to determine aircraft altitude since the vertical error
can be quite large."

GPS altitude is measured above the GPS sphere, which is not sea level.

Bob Gardner

"Aluckyguess" wrote in message
news
How come the GPS reads a different altitude than the Altimeter?

"Bob Gardner" wrote:
AIM 1-1-19(a)(8) tells pilots not to use GPS altitude: "GPS altitude
should not be relied upon to determine aircraft altitude since the
vertical error can be quite large."

Except when using WAAS, when it is quite small.

--
Dan
C172RG at BFM