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Subject: Re: Leg 67 - I give up!
From: Dan Hogan (dhhogan@XXX.XXX)
Date: Thu Jul 20 2000 - 09:30:42 EDT
Paul:
Sorry my GOOF! See below and revised Leg 67 posted same time as this
message.
On 20 Jul 2000, at 2:47, Paul Hirose wrote:
> After wasting far too much time today on Leg 67, I'm giving up. Have
> not been able to solve the celestial fix. The problem is that only the zone
> time of the shots is given. Not having worked any of the recent Silicon Sea
> legs, I don't have the dead reckoning longitude necessary to convert zone
> time to UT.
Apply the Zone Description(ZD) to the ZT for UTC time.
ZD= DR Lon / 15
> >From the wording of the problem, I inferred that sailing 614 mi on
> course 290 would take us toward Barbados, but we wouldn't be there
> yet. So, with a small scale chart, I backed up 700 mi from Barbados on the
> reciprocal course, and took that as the assumed position for my sight
> reduction. My LOPs showed the guess was far off, but they did cluster well
> enough for me get an improved assumed position. With that and a
> larger-scale chart I re-reduced the sights. Unfortunately, the first two
> sights I reduced still had big intercepts. At that point I called it quits.
> No doubt some blunders on my part have not helped; I haven't done celestial
> in a long time.
Paul:
My apploogies. I left out the EP position. EP= (02d 22.8'N 29d 24.9'W)
[Snip correct assumption and tedious practice]
Dan Hogan
dhhogan@XXX.XXX
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