nal Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of b...@lysator.liu.se
Sent: Thursday, January 14, 2010 4:09 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Weird T-Bolt elevation readings...
Hi Bruce,
> T
Björn
In the case of the Thunderbolt with the default WGS84 datum the height
is calculated with respect to the MSL geoid.
If another datum is selected the height is calculated with respect to
the ellipsoid.
The attached snapshot from the Thunderbolt book makes this clear.
The MSL goeid doesnt
Yes, the error is almost certainly due to the difference between the true
earth surface and the value calculated by the GPS model of the earth surface.
The difference is Dallas, Texas is around 26 meters (and John Miles actually
does live in a pineapple under the sea, so his altitude is ne
Hi Bruce,
> The GPS altitude is calculated with respect to the geoid.
No, the GPS calculates altitude wrt the ellipsoid. Then its a conversion
with lots of coefficients or a lookup table to add the geoid separation.
Altitude wrt to the geoid is the same as Mean Sea level, which is what
normal map
I wonder if this is a HAE vs. MSL issue? What is the
elevation delta for your location in FL? It's about 18
meters for me in Seattle.
Mark, do you know?
/tvb
Hello, TimeNutters--
While we are on a thread about Trimble T-bolts,
perhaps someone might expand on why my T-bolt
does not ever come
The GPS altitude is calculated with respect to the geoid.
The geoid surface may have a vertical separation from the actual surface
by several meters.
This correction varies with location on the Earth's surface.
Bruce
Michael Baker wrote:
Hello, TimeNutters--
While we are on a thread about Tr
o know about it.
Didier
--Original Message--
From: Michael Baker
Sender: time-nuts-boun...@febo.com
To: Time-Nuts
ReplyTo: Time-Nuts
Subject: [time-nuts] Weird T-Bolt elevation readings...
Sent: Jan 14, 2010 2:28 PM
Hello, TimeNutters--
While we are on a thread about Trimble T-bolts,
perhap
Hello, TimeNutters--
While we are on a thread about Trimble T-bolts,
perhaps someone might expand on why my T-bolt
does not ever come up with altitude readings that
are even close. After a long fix, the Lat-Lon
coordinates are pretty close, but the altitude
is always given as around 2 meters. W
