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Re: Newbie - Variation Question

Subject: Re: Newbie - Variation Question
From: Pierre Boucher (pboucher@XXX.XXX)
Date: Mon Feb 11 2002 - 11:02:15 EST

Hi Andrew,

That is the way the french deal with variation (declinaison)

The basic formula being:
True + Variation = Magnetic

They consider :
West variation as positive and
East variation as negative

So the negative East variation is added to True to get the Magnetic.

Hope this help,

Pierre Boucher

>I realise the list is for non electronic navigation methods but I need some
>confirmation on an issue of magnetic variation.
>
>I recently purchased a hand held GPS to back up my celestial on my first
>offshore trip (solo). Whilst I was familiarising myself with the unit the
>other day, I found after much head scratching that the unit actually ADDS
>easterly variation to true to get a magnetic heading readout.
>
>I was always taught that "variation east, magnetic least" - all my
>navigation text books including Bowditch back this up.
>
>I contacted the Australian importer of the GPS this morning who said they
>had been aware of the problem for 18 months, had taken the issue up with MLR
>France ( the manufacturer)
>and were advised that it was the way that the French deal with variation( ie
>add rather than subtract Easterly variation to get magnetic course). The
>importer said they were happy with this explanation.
>
>Anyway, I just wanted to confirm that the world over that Easterly variation
>is subtracted from true to get magnetic. If it isn't, well at least I've
>learned something today.
>
>Thanks in advance.
>
>Andrew

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