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Re: Recovering Time by Time Sight
From: Hewitt Schlereth
Date: 2012 Dec 18, 09:02 -0800

Greg, does it have to be at the PV? Given an exact latitude won't the time sight formula give an exact longitude? After all, that's what we've been doing with slide rules and tables the last few days. And hitting it within a few minutes of arc, or between 8 and 12 seconds of time.

Assuming, natch, that the GPS is spot on. :-)

Hewitt

Sent from my iPad

On Dec 18, 2012, at 8:35 AM, "Greg Rudzinski" <gregrudzinski@yahoo.com> wrote:

The time sight at prime vertical is the ideal observation for recovering time if the chronometer should ever stop. If at port then the exact latitude and longitude is known which should give the navigator a recovered time to plus or minus 8 seconds by converting the difference between known longitude and observed time sight longitude to time which is then added or subtracted from the restarted chronometer to get UT. Reworking the time sight with the corrected time would be the check. The reduction would have to be by trig tables to get the needed precision.
Greg Rudzinski
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