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Topic: magnetic declination, update older maps< Next Oldest | Next Newest >
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DonCravens Search for posts by this member.

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PostIcon Posted on: Dec. 07 2012, 6:28 pm  Skip to the next post in this topic. Ignore posts   QUOTE

I have some topos which are about 15 years old. I would like to update the magnetic declination on them and was hoping someone could advise on how to do it.
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Tigger Search for posts by this member.
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PostIcon Posted on: Dec. 07 2012, 6:33 pm Skip to the previous post in this topic. Skip to the next post in this topic. Ignore posts   QUOTE

You can find your current declination here. Each map would need to be updated based upon it's location.

http://magnetic-declination.com/


Welcome to the forums. Any thoughts on who would win a battle between Spiderman and Batman?...and bacon?


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If I'm going to be lost, in the woods is where I want to be...
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PostIcon Posted on: Dec. 07 2012, 7:47 pm Skip to the previous post in this topic. Skip to the next post in this topic. Ignore posts   QUOTE

You can also measure declination in the field by comparing an observed bearing to the map bearing between the same two features.
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red dog Search for posts by this member.
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PostIcon Posted on: Dec. 07 2012, 7:56 pm Skip to the previous post in this topic. Skip to the next post in this topic. Ignore posts   QUOTE

Hey, grab some old maps and look

Rincon Mtns here used to be 13 deg , now 10.2 (east)


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PostIcon Posted on: Dec. 07 2012, 11:58 pm Skip to the previous post in this topic.  Ignore posts   QUOTE


(Tigger @ Dec. 07 2012, 5:33 pm)
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You can find your current declination here. Each map would need to be updated based upon it's location.

http://magnetic-declination.com/


Welcome to the forums. Any thoughts on who would win a battle between Spiderman and Batman?...and bacon?

Easiest is to use this calculator.

The rates of change...well, they change for each region over time so the older your map, the more manual mathematical work you have to do to manually adjust your declination.

http://www.kayelaby.npl.co.uk/general_physics/2_7/2_7_6.html


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4 replies since Dec. 07 2012, 6:28 pm < Next Oldest | Next Newest >

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