Re: Turning on flat skis?

On Dec 1, 5:04 pm, A mighty Hungarian warrior<Ha...@xxxxxxxxxx> wrote:
On Tue, 1 Dec 2009 16:48:39 -0800 (PST), Richard Henry
<pomer...@xxxxxxxxxxx> wrote this crap:

One limitation of using GPS is that position updates are only
available once per second.

Really?  I just bought a Garmin Nuvi 1300 for my car and it appears to
update more than once a second.  I drive down the highway at over
60mph and it has no problem keeping track of where I am at.  At 60mph
I am moving at 88 feet per second, (do the math,) and the GPS doesn't
jump around every 88 feet.

Really.  Each GPS satellite sends a waveform which is timed as closely
as possible to be synchronized to the beginnig of each Universal Time
Coordinate second.

Wow.  Tell me something i didn't know.

You apparently don't know that since the calculation depends on a once-
per-second waveform the information only updates once per second.
(Unless you have one of those alleged milli-second-scale hyper-secret
GPS receivers that we're not going to talk about here.)

The receiver calculates GPS position reports by
measuring the time delay of satellite signals from the "true"
beginning of each UTC second.  The receiver determines what it
presumes to be true UTC time by comparing deviations from a presumed
UTC second and then adjusting the time estimate to minimize the multi-
satellite errors.

Really.  Tell me something I didn't know.  How do you get your hair
like that?

All seriousness aside, the GPS does millions of calculations each
second.

I also have an atomic clock on my yacht, and guess what?  The time is
the same.  Isn't it amazing how these electronic thingies work?

I doubt very much that you have an atomic clock on your yacht, unless
your yacht is about the size of a USN destroyer. I would not be
surprised at all that you have a GPS clock on your yacht, or even on
your wrist. You can even get them at Wal*Mart now. You can get GPS
time correct to 1 second even if you can only receive the signal from
one GPS satellite.
.

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