If I had, or borrowed, a GPS, global postioning system, would it also
show my altitude?

Or, is there some moderately priced device that would show altitude to
say the nearest 10 feet? Do they rent them?

Thanks.

On Fri, 04 Dec 2009 13:39:40 -0500, mm
wrote:

If I had, or borrowed, a GPS, global postioning system, would it also
show my altitude?

Or, is there some moderately priced device that would show altitude to
say the nearest 10 feet? Do they rent them?

Thanks.

Most GPSes do show altitude (on my Garmin Nuvi 350, the satellite
reception screen shows coordinates and elevation), but beware --
because of the location of the satellites in the sky, altitude is much
less accurate than longitude and latitude. I'd say it's +/- 100 feet
typically, based on comparisons with roadside elevation signs and a
barometric altimeter.

I don't know if more expensive commercial devices have better
accuracy, perhaps by incorporating a barometric sensor into the
device.

Josh

"mm" wrote in message
...
If I had, or borrowed, a GPS, global postioning system, would it also
show my altitude?

Or, is there some moderately priced device that would show altitude to
say the nearest 10 feet? Do they rent them?

Thanks.

My Garmin shows altitude, but I don't know that all of them do. You can get
elevations from Google Earth if you are looking for just a spot or two.
The GPS and Google Earth are within a couple of feet of each other so if not
accurate, they are consistent.

On Fri, 04 Dec 2009 13:39:40 -0500, mm
wrote:

If I had, or borrowed, a GPS, global postioning system, would it also
show my altitude?

Depends on the brand/model.

Or, is there some moderately priced device that would show altitude to
say the nearest 10 feet?

Garmin ETrex hand held I own shows altitude if you desire.
Some models for street navigation may or may not.

Do they rent them?

Do who rent them?

On Fri, 4 Dec 2009 13:56:54 -0500, "Ed Pawlowski"
wrote:


"mm" wrote in message
.. .
If I had, or borrowed, a GPS, global postioning system, would it also
show my altitude?

Or, is there some moderately priced device that would show altitude to
say the nearest 10 feet? Do they rent them?

Thanks.

My Garmin shows altitude, but I don't know that all of them do. You can get

Josh's 100 feet is not precise enough,

elevations from Google Earth if you are looking for just a spot or two.

so I guess it will be google earth. I dl'd it months ago but haven't
installed it. I'll do that.

The GPS and Google Earth are within a couple of feet of each other so if not
accurate, they are consistent.

Good enough, and I wanted to compare elevations anyhow. Hmmm. I
should have said that. So maybe Joshe's 100 feet is good enough.
Even if a gps is off by 100 feet, if it is off by the same amount a
couple blocks away, that would be fine. Now I have to find someone I
know who has a gps. Believe it or not, none of the six people I see
most often do.

Thanks all.

mm wrote:

If I had, or borrowed, a GPS, global postioning system, would it also
show my altitude?

Or, is there some moderately priced device that would show altitude to
say the nearest 10 feet? Do they rent them?

Thanks.

Ask the janitor?

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10e12 furlongs per fortnight.

On Dec 4, 1:39*pm, mm wrote:
If I had, or borrowed, a GPS, global postioning system, would it also
show my altitude?

Possibly, maybe probably it would "indicate" altitude, with varying
degrees of accuracy.

Or, is there some moderately priced device that would show altitude to
say the nearest 10 feet?

A USGS 7.5 minute map is, or used to be $4.

There are a lot of variables.
http://www.maptools.com/UsingUTM/mapdatum.html
http://www.esri.com/news/arcuser/0703/geoid1of3.html
http://gps.afspc.af.mil/gpsoc/
http://edu-observatory.org/gps/height.html
-----

- gpsman

mm wrote:
If I had, or borrowed, a GPS, global postioning system, would it also
show my altitude?

Or, is there some moderately priced device that would show altitude to
say the nearest 10 feet? Do they rent them?

Thanks.
Hi,
I don't know about renting but I have a Casio G-shock watch which gives
altitude display. Before initial use, you need to calibrate it. When
I go alpine trekking I use it.

On Fri, 04 Dec 2009 18:40:07 -0500, jeff_wisnia
wrote:

mm wrote:

If I had, or borrowed, a GPS, global postioning system, would it also
show my altitude?

Or, is there some moderately priced device that would show altitude to
say the nearest 10 feet? Do they rent them?

Thanks.

Ask the janitor?

Jeff
GPS is accurate in altitude to the same degree it is in location - so
it COULD be accurate to within 3 feet - or 30. Depending on how good a
satelite fix you get.

On Fri, 04 Dec 2009 19:00:08 -0700, Tony Hwang
wrote:

mm wrote:
If I had, or borrowed, a GPS, global postioning system, would it also
show my altitude?

Or, is there some moderately priced device that would show altitude to
say the nearest 10 feet? Do they rent them?

Thanks.
Hi,
I don't know about renting but I have a Casio G-shock watch which gives
altitude display. Before initial use, you need to calibrate it. When
I go alpine trekking I use it.
Aneroid (barometric) altimiter - it looses accuracy very quickly when
a storm front comes in. Lots of Ultralite and hang-glider pilots use
them though.

wrote:
On Fri, 04 Dec 2009 19:00:08 -0700, Tony Hwang
wrote:

mm wrote:
If I had, or borrowed, a GPS, global postioning system, would it also
show my altitude?

Or, is there some moderately priced device that would show altitude to
say the nearest 10 feet? Do they rent them?

Thanks.
Hi,
I don't know about renting but I have a Casio G-shock watch which gives
altitude display. Before initial use, you need to calibrate it. When
I go alpine trekking I use it.
Aneroid (barometric) altimiter - it looses accuracy very quickly when
a storm front comes in. Lots of Ultralite and hang-glider pilots use
them though.

That would only be in low end units. Kollsman was the one who first
devised a method to compensate for changes in barometric pressure from
standard pressure.

mm wrote:
On Fri, 4 Dec 2009 13:56:54 -0500, "Ed Pawlowski"
wrote:

"mm" wrote in message
...
If I had, or borrowed, a GPS, global postioning system, would it also
show my altitude?

Or, is there some moderately priced device that would show altitude to
say the nearest 10 feet? Do they rent them?

Thanks.
My Garmin shows altitude, but I don't know that all of them do. You can get

Josh's 100 feet is not precise enough,

elevations from Google Earth if you are looking for just a spot or two.

so I guess it will be google earth. I dl'd it months ago but haven't
installed it. I'll do that.

The GPS and Google Earth are within a couple of feet of each other so if not
accurate, they are consistent.

Good enough, and I wanted to compare elevations anyhow. Hmmm. I
should have said that. So maybe Joshe's 100 feet is good enough.
Even if a gps is off by 100 feet, if it is off by the same amount a
couple blocks away, that would be fine. Now I have to find someone I
know who has a gps. Believe it or not, none of the six people I see
most often do.

Thanks all.

Google earth pretty much agrees with old US contour maps I have of my
house. My old ETrex will not give that kind of accuracy but when I use
it out in the field, altitude and location will vary much more than the
specs you want.

"Josh" wrote in message
...

: Most GPSes do show altitude (on my Garmin Nuvi 350, the satellite
: reception screen shows coordinates and elevation), but beware --
: because of the location of the satellites in the sky, altitude is much
: less accurate than longitude and latitude. I'd say it's +/- 100 feet
: typically, based on comparisons with roadside elevation signs and a
: barometric altimeter.

The difference between 'altitude and 'elevation' - is it just semantics or
is there a difference? I've always taken 'elevation' to mean distance above
the ground, and 'altitude' to be distance above sea level. I believe pilots
assume the same as I - if you were flying at 1000' 'altitude' near 1500'
hills, you'd be in trouble.

Joe wrote:
wrote in message
...

: Most GPSes do show altitude (on my Garmin Nuvi 350, the satellite
: reception screen shows coordinates and elevation), but beware --
: because of the location of the satellites in the sky, altitude is much
: less accurate than longitude and latitude. I'd say it's +/- 100 feet
: typically, based on comparisons with roadside elevation signs and a
: barometric altimeter.

The difference between 'altitude and 'elevation' - is it just semantics or
is there a difference? I've always taken 'elevation' to mean distance above
the ground, and 'altitude' to be distance above sea level. I believe pilots
assume the same as I - if you were flying at 1000' 'altitude' near 1500'
hills, you'd be in trouble.


Hi,
Consumer GPS readings are diluted from accurate military readings coming
from the satellite. That is why ~ +/ 100 ft. tolerance.

On Sat, 05 Dec 2009 15:42:44 -0700, Tony Hwang
wrote:

[snip]

Hi,
Consumer GPS readings are diluted from accurate military readings coming
from the satellite. That is why ~ +/ 100 ft. tolerance.

Would that be the "selective availability" that was turned off in
2000?

Gary H wrote:
On Sat, 05 Dec 2009 15:42:44 -0700, Tony Hwang
wrote:

[snip]

Hi,
Consumer GPS readings are diluted from accurate military readings coming
from the satellite. That is why ~ +/ 100 ft. tolerance.

Would that be the "selective availability" that was turned off in
2000?

Consumer GPS readings aren't "diluted" in the true sense. That would be
the "selective availability" you mentioned which is no longer used.

The GPS system also transmits "P(Y) code" which is encrypted. That code
enables higher precision but consumer receivers can't decrypt it.

On Dec 5, 7:02�pm, George wrote:
Gary H wrote:
On Sat, 05 Dec 2009 15:42:44 -0700, Tony Hwang
wrote:

[snip]

Hi,
Consumer GPS readings are diluted from accurate military readings coming
from the satellite. That is why ~ +/ 100 ft. tolerance.

Would that be the "selective availability" that was turned off in
2000?

Consumer GPS readings aren't "diluted" in the true sense. That would be
the "selective availability" you mentioned which is no longer used.

The GPS system also transmits "P(Y) code" which is encrypted. That code
enables higher precision but consumer receivers can't decrypt it.

recently mine dont appear as accurate, wonder if the satellites are
failing? or more likely spread futher apart and fewer equal less
accurate?

On Sat, 05 Dec 2009 07:39:02 -0500, George
wrote:

wrote:
On Fri, 04 Dec 2009 19:00:08 -0700, Tony Hwang
wrote:

mm wrote:
If I had, or borrowed, a GPS, global postioning system, would it also
show my altitude?

Or, is there some moderately priced device that would show altitude to
say the nearest 10 feet? Do they rent them?

Thanks.
Hi,
I don't know about renting but I have a Casio G-shock watch which gives
altitude display. Before initial use, you need to calibrate it. When
I go alpine trekking I use it.
Aneroid (barometric) altimiter - it looses accuracy very quickly when
a storm front comes in. Lots of Ultralite and hang-glider pilots use
them though.

That would only be in low end units. Kollsman was the one who first
devised a method to compensate for changes in barometric pressure from
standard pressure.
Yes, but you can bet the wrist-watch style is NOT a Kollsman, and to
compensate even a Kollsman you need to know ground level, or better
yet, sea level adjusted barometric pressure.

On Sat, 5 Dec 2009 16:23:23 -0600, "Joe" wrote:


"Josh" wrote in message
.. .

: Most GPSes do show altitude (on my Garmin Nuvi 350, the satellite
: reception screen shows coordinates and elevation), but beware --
: because of the location of the satellites in the sky, altitude is much
: less accurate than longitude and latitude. I'd say it's +/- 100 feet
: typically, based on comparisons with roadside elevation signs and a
: barometric altimeter.

The difference between 'altitude and 'elevation' - is it just semantics or
is there a difference? I've always taken 'elevation' to mean distance above
the ground, and 'altitude' to be distance above sea level. I believe pilots
assume the same as I - if you were flying at 1000' 'altitude' near 1500'
hills, you'd be in trouble.



I don't think there is any difference. Mainly it's that if you are in
the air it's thought of as altitude and if you are standing on the
ground it's thought of as elevation but they are the same, both are
above sea level.

On Fri, 04 Dec 2009 22:23:38 -0500, wrote:

On Fri, 04 Dec 2009 18:40:07 -0500, jeff_wisnia
wrote:

mm wrote:

If I had, or borrowed, a GPS, global postioning system, would it also
show my altitude?

Or, is there some moderately priced device that would show altitude to
say the nearest 10 feet? Do they rent them?

Thanks.

Ask the janitor?

Jeff
GPS is accurate in altitude to the same degree it is in location - so
it COULD be accurate to within 3 feet - or 30. Depending on how good a
satelite fix you get.

I don't think that's correct, due to the geometry, GPS is much more
accurate with lat/long info then it is with elevation info.

"mm" wrote in message
...
If I had, or borrowed, a GPS, global postioning system, would it also
show my altitude?

Or, is there some moderately priced device that would show altitude to
say the nearest 10 feet? Do they rent them?

Thanks.

Garmin 12xl. Available cheap on ebay. Bulletproof. Accurate to your
described tolerances.

Steve

"Joe" wrote in message
...

"Josh" wrote in message
...

: Most GPSes do show altitude (on my Garmin Nuvi 350, the satellite
: reception screen shows coordinates and elevation), but beware --
: because of the location of the satellites in the sky, altitude is much
: less accurate than longitude and latitude. I'd say it's +/- 100 feet
: typically, based on comparisons with roadside elevation signs and a
: barometric altimeter.

The difference between 'altitude and 'elevation' - is it just semantics or
is there a difference? I've always taken 'elevation' to mean distance
above
the ground, and 'altitude' to be distance above sea level. I believe
pilots
assume the same as I - if you were flying at 1000' 'altitude' near 1500'
hills, you'd be in trouble.

Define "is".

wrote:
On Dec 5, 7:02�pm, George wrote:
Gary H wrote:
On Sat, 05 Dec 2009 15:42:44 -0700, Tony Hwang
wrote:
[snip]
Hi,
Consumer GPS readings are diluted from accurate military readings coming
from the satellite. That is why ~ +/ 100 ft. tolerance.
Would that be the "selective availability" that was turned off in
2000?
Consumer GPS readings aren't "diluted" in the true sense. That would be
the "selective availability" you mentioned which is no longer used.

The GPS system also transmits "P(Y) code" which is encrypted. That code
enables higher precision but consumer receivers can't decrypt it.

recently mine dont appear as accurate, wonder if the satellites are
failing? or more likely spread futher apart and fewer equal less
accurate?

I haven't noticed a difference. If anything the lowest performing GPS I
have (smartphone with GPS chipset) has been performing better.

wrote:
On Fri, 04 Dec 2009 18:40:07 -0500, jeff_wisnia
wrote:

mm wrote:

If I had, or borrowed, a GPS, global postioning system, would it also
show my altitude?

Or, is there some moderately priced device that would show altitude to
say the nearest 10 feet? Do they rent them?

Thanks.
Ask the janitor?

Jeff
GPS is accurate in altitude to the same degree it is in location - so
it COULD be accurate to within 3 feet - or 30. Depending on how good a
satelite fix you get.

It could be if the earth wasn't in the way. X & Y are more accurate than
Z (vertical) because of where the satellites are relative to a user. For
Z to be as accurate your GPS would need to see satellites that are well
below the horizon.

wrote:
On Sat, 05 Dec 2009 07:39:02 -0500, George
wrote:

wrote:
On Fri, 04 Dec 2009 19:00:08 -0700, Tony Hwang
wrote:

mm wrote:
If I had, or borrowed, a GPS, global postioning system, would it also
show my altitude?

Or, is there some moderately priced device that would show altitude to
say the nearest 10 feet? Do they rent them?

Thanks.
Hi,
I don't know about renting but I have a Casio G-shock watch which gives
altitude display. Before initial use, you need to calibrate it. When
I go alpine trekking I use it.
Aneroid (barometric) altimiter - it looses accuracy very quickly when
a storm front comes in. Lots of Ultralite and hang-glider pilots use
them though.
That would only be in low end units. Kollsman was the one who first
devised a method to compensate for changes in barometric pressure from
standard pressure.
Yes, but you can bet the wrist-watch style is NOT a Kollsman, and to
compensate even a Kollsman you need to know ground level, or better
yet, sea level adjusted barometric pressure.

I have seen the both the electronic version and analog version of the
wris****ch style that have Kollsman correction. Barometric pressure is
available from a lot of sources anymore and there are certainly a lot of
places where elevation is known.

In article ,
George wrote:


I have seen the both the electronic version and analog version of the
wris****ch style that have Kollsman correction. Barometric pressure is
available from a lot of sources anymore and there are certainly a lot of
places where elevation is known.

Yeah, you don't need to know barometric pressure if you know your
starting elevation. SOP for pilots is to set the altimeter to the field
elevation before takeoff. Along the way and prior to landing, it's
corrected based on reported barometric pressure for the new locale.

In article ,
"Joe" wrote:

"Josh" wrote in message
...

: Most GPSes do show altitude (on my Garmin Nuvi 350, the satellite
: reception screen shows coordinates and elevation), but beware --
: because of the location of the satellites in the sky, altitude is much
: less accurate than longitude and latitude. I'd say it's +/- 100 feet
: typically, based on comparisons with roadside elevation signs and a
: barometric altimeter.

The difference between 'altitude and 'elevation' - is it just semantics or
is there a difference? I've always taken 'elevation' to mean distance above
the ground, and 'altitude' to be distance above sea level. I believe pilots
assume the same as I - if you were flying at 1000' 'altitude' near 1500'
hills, you'd be in trouble.

Pilots have about six different types of altitude. "MSL" is above mean
sea level. "AGL" is above ground level. "Indicated" is whatever your
altimeter says, even if it's not right due to changes in barometric
pressure since it was last set. There's also "density" altitude,
"pressure" altitude, and "true" altitude, not to mention "absolute"
altitude.

I think "elevation" means the same as "MSL altitude."

Pilots use a lot of obvious and not-so-obvious tricks to keep them from
flying into the side of a mountain. When those tricks fail, we
euphemistically call it "failure to outclimb the terrain."

On Dec 4, 1:39*pm, mm wrote:
If I had, or borrowed, a GPS, global postioning system, would it also
show my altitude?

Or, is there some moderately priced device that would show altitude to
say the nearest 10 feet? * Do they rent them?

Thanks.

I ve taken mine out to several precision surveyed locations and the
Lat long is very close, maybe 1 M, but altitude is all over the place.

Jimmie

On Dec 6, 8:51*am, George wrote:
wrote:
On Sat, 05 Dec 2009 07:39:02 -0500, George
wrote:

wrote:
On Fri, 04 Dec 2009 19:00:08 -0700, Tony Hwang
wrote:

mm wrote:
If I had, or borrowed, a GPS, global postioning system, would it also
show my altitude?

Or, is there some moderately priced device that would show altitude to
say the nearest 10 feet? * Do they rent them?

Thanks.
Hi,
I don't know about renting but I have a Casio G-shock watch which gives
altitude display. Before initial use, you need to calibrate it. When
I go alpine trekking I use it.
*Aneroid (barometric) altimiter - it looses accuracy very quickly when
a storm front comes in. Lots of Ultralite and hang-glider pilots use
them though.
That would only be in low end units. Kollsman was the one who first
devised a method to compensate for changes in barometric pressure from
standard pressure.
*Yes, but you can bet the wrist-watch style is NOT a Kollsman, and to
compensate even a Kollsman you need to know ground level, or better
yet, sea level adjusted barometric pressure.

I have seen the both the electronic version and analog version of the
wris****ch style that have Kollsman correction. Barometric pressure is
available from a lot of sources anymore and there are certainly a lot of
places where elevation is known.- Hide quoted text -

- Show quoted text -

Most people dont realize how accurate barometers can be. I had a
chance to play around with one that coud discern whether or not it was
setting on my work bench or the test equipment shelf above the work
bench a distance of about 18 inches.

Jimmie

since the gPSA knows WHERE YOU ARE, within a few feet it should have
your altitude

If I had, or borrowed, a GPS, global postioning system, would it also
show my altitude?


Yes, my very OLD Magellan 315 GPS does

On Dec 4, 9:00*pm, Tony Hwang wrote:

I don't know about renting but I have a Casio G-shock watch which gives
altitude display. Before initial use, you need to calibrate it. When
I go alpine trekking I use it.

I had (RIP) a ski buddy who was nuts about how many vertical feet he
could get in x time. He had some kind of barometer/recorder. I
measure my skiing in fun/yard sales/injuries.

This is a (used) prototype of the first GPS watch (needs a battery and
a dusting).
http://i48.tinypic.com/2yvmmw8.jpg
http://i45.tinypic.com/2mn0nr.jpg

It'll get you within 100 yards, horizontally, under any conditions
where you have sufficient landmarks to triangulate a position, like,
on top of a mountain.

On top of a mountain, at night, it's still nearly as good as anything
now available.
-----

- gpsman

GPSman..Hmmmm..
Do you know where I can get a copy of the Magellan DATAsend CD Rom for a
Magellan 315 handheld GPS ? Its the DATASEND I'm looking for, not the
MAPsend

R