# NavList:

## A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

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Re: Time Sight usage
From: Henry Halboth
Date: 2013 Jan 13, 21:15 -0500
Kermit,

Your assumptions with respect to time and altitude corrections are entirely correct.

Thank you so very much for your interest.

Regards,

Henry

On Sun, Jan 13, 2013 at 12:08 AM, Antoine Couëtte wrote:

Hello to all,

Let me complement my last post (Date: 12 Jan 2013 02:35) by the following one.

From trial and error, I have come to the conclusion that the Feb 23rd, 1949 observations can be processed to day as follows :

TT-UT = +28.7 seconds of time

Height of eye : 54 ft, standard conditions because I could find any different data on it (while T is certainly above the 15C I have been using)

I have assumed that given times are UT1 and have been corrected for the Chronometer Error indicated as being -4 minutes and 11 seconds of time,

I have also surmised that the quoted altitude are corrected for only instrumental error, and the the usual corrections (dip, refraction, SD as applicable) need to be be performed.

I have used our standard LOP calculation procedure from a position of N05d05'8 W001d13'9 which I believe is the Observer's final position.

Results as follows :

SUNL : (1) UT=12h14m55.0s H=74d53'3 i=-0.2NM (A)Z=176.7d
(2) 12h16m09.0s 74d54'3 +0.4NM (T) 177.8d
(3) 12h17m52.0s 74d54'9 -0.2NM (A) 179.5d
(4) 12h19m35.0s 74d55'1 +0.1NM (T) 181.1d
(5) 12h21m35.0s 74d53'9 +0.0NM (T) 183.0d

SIRIUS 18h17m27.0s 49d51'4 -0.1NM (A) 123.4d
PROCYON 18h31m37.0s 46d09'2 +0.2NM (T) 087.6d

with all these results I am getting an observed position quasi-identical to the one used as DR, with a LOP's dispersion of 0.2 NM

interesting to see the Azimut of Sirius.

Best Regards to all

Kermit
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