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Author
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Topic: Celestial Navigation 2nd edition; ex.6.5
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eisen
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posted September 03, 2015 10:30 AM
So far I've been able to work though the hurtles, but I've indeed reached an impasse in chapter 6. I've accomplished all the exercises with consistent results unto this point and I think i understand the Running Fix procedure but I cannot get my work to agree with the answers. I am missing something and cannot see what it is.
The first thing I came across is a discrepancy on #6 sun shight; Zn. I used the rule for N Lat; Zn= 360-Z; 223=360-137. The answer uses 137 degrees;Z, not 223.
Second, #7 uses Zn 190 which isn't even the Z for the pub 249 data; LHA 9, Dec deg S12 contrary names.
In general my plotting sheet, though very close does not look the same as the one in the book even though I use the same data to plot DR and the two APs. Ive checked and rechecked my angles and distances to no avail- there is something amiss.
Thanks for taking the time to help me with this,
Andrew
From: eisen
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Capt Steve Miller
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posted September 03, 2015 12:19 PM
Looking at the problem 6.5 Sun sight #6, I see that the LHA is 320°, Dec - S 12°, a-Lat is 45° N. I see that the z is 137 in the 249 Table for 45° Contrary. Using the rules for the Zn - when LHA is greater than 180° then Zn = Z. Thus the Zn is 137° in this problem.
Looking at the problem 6.5 Sun sight #7, I see that the LHA is 9°, Dec - S 12°, a-Lat is 45° N. I see that the z is 170 in the 249 Table for 45° Contrary. Using the rules for the Zn - when LHA is less than 180° then Zn = 360 - Z. Thus the Zn is 360° - 170° = 190° in this problem.
From: Starpath
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eisen
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posted September 04, 2015 09:02 AM
Thank you Capt Miller. I see the err in my procedure.
From: eisen
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