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Old 29-10-2012, 02:34
KASUNDEL KASUNDEL is offline
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Location: Doha - Qatar
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Unhappy How to Interpolate to - forgotten

Hi BGS,

Can anyone explain how to interpolate on air almanac to solve problems for sunset & sunrise LMT.

Thanks

Kas.
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Old 29-10-2012, 14:10
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Tony Pike Tony Pike is offline
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Default Re: How to Interpolate to - forgotten

Okey dokey,

See image below.

The blue box is dated 02nd January but falls across two latitudes, N 56 and N 58.

If you are looking for the Sunrise time on 2nd January at N 57, you simply take the average of these two times.

N 58 = 08.45
N 56 = 08.31

(16.76 / 2 = 08.38)


The red box is looking for a time at N 70 on a date between 20 - 23 January.

20/01 = 11.06
23/01 = 10.42

Look at the difference between 10.42 and 11.06 = 24 minutes.

24 minutes / 3 = 8 minutes (You need to divide by 3 as there are 3 days difference between 20th and 23rd)

Therefore:

20/01 = 11.06
21/01 = 10.58
22/01 = 10.50

23/01 = 10.42

The green box requires two way interpolation to find a time at a date between 26th and 29th and at a latitude between N 62 and N 64, let's say N 63 on 27th.

DATE 26th - 27th - 28th - 29th
N 64 08.58 ***********08.49
N 63 08.49 08.46 08.44 08.41
N 62 08.41 ***********08.34

It is extremely difficult trying to be absoutely accurate with these and to be honest +/- 1 or 2 minutes is neither here nor there.

You will not be expected to intepolate to 1 minute of accuracy in the exams.

Hope that helps.
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Last edited by Tony Pike; 29-10-2012 at 14:24.
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  #3  
Old 30-10-2012, 03:58
KASUNDEL KASUNDEL is offline
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Thumbs up Re: How to Interpolate to - forgotten

Hi Tony,

This is simply one of the best explanations I ve received. Thanks a million.

Cheers,

Kas
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