From: Hal Murray <hmurray@megapathdsl.net>
To: esr@thyrsus.com
Cc: thumbgps-devel@lists.bufferbloat.net, hmurray@megapathdsl.net,
gpsd-dev@nongnu.org
Subject: Re: [Thumbgps-devel] [gpsd-dev] PPS over USB
Date: Wed, 02 May 2012 00:58:08 -0700 [thread overview]
Message-ID: <20120502075808.6CC7880003B@ip-64-139-1-69.sjc.megapath.net> (raw)
In-Reply-To: Message from "Eric S. Raymond" <esr@thyrsus.com> of "Tue, 01 May 2012 23:33:45 EDT." <20120502033345.GA11913@thyrsus.com>
esr@thyrsus.com said:
> Clock time should be OK even with a single sat - multiple birds are needed
> for the spherical trig to compute position, but atomic time you get directly
> from each sat sample.
I think it's more complicated than that.
You can get time with only 1 sat if know where you are located. It takes
special software, usually called "timing".
The usual approach for finding the location is to do a "survey". That
requires more special software which is usually included in the timing
package. It collects a 1000 (or whatever) good samples and averages the
position. The "good" qualifier means they don't use low-quality samples
which might be way off.
It's worth asking Navisys if they have the timing mode software.
--
These are my opinions, not necessarily my employer's. I hate spam.
next prev parent reply other threads:[~2012-05-02 7:58 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20120501151435.4a6a5373.gem@rellim.com>
2012-05-01 22:16 ` [Thumbgps-devel] Fwd: " Dave Taht
2012-05-02 1:40 ` [Thumbgps-devel] " Dave Taht
2012-05-02 3:07 ` Jim Thompson
2012-05-02 3:33 ` Eric S. Raymond
2012-05-02 7:58 ` Hal Murray [this message]
2012-05-06 21:28 ` Eric S. Raymond
2012-05-02 11:09 ` tz
[not found] ` <20120502131310.7dd7f799.gem@rellim.com>
2012-05-02 20:33 ` tz
2012-05-02 21:19 ` Hal Murray
2012-05-02 21:43 ` tz
2012-05-02 13:40 ` Ron Frazier (NTP)
[not found] ` <20120502124227.28ef9fa6.gem@rellim.com>
2012-05-03 4:07 ` Ron Frazier (NTP)
2012-05-06 22:09 ` Eric S. Raymond
[not found] ` <4FA43068.2080606@wildgooses.com>
[not found] ` <20120504160455.4514ac26.gem@rellim.com>
[not found] ` <20120506214138.GB14699@thyrsus.com>
[not found] ` <4FA6F396.70307@tmsw.no>
[not found] ` <4FA7BDF1.7030708@wildgooses.com>
[not found] ` <4FA7CFB2.9080807@tmsw.no>
[not found] ` <4FA7E197.9010902@wildgooses.com>
[not found] ` <20120507205843.GA21259@thyrsus.com>
2012-05-07 21:14 ` Dave Taht
2012-05-07 21:52 ` Eric S. Raymond
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