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Declination Assistance Needed


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Is there a website or other source out there that gives declination for various locales? I was looking at an old Scout Fieldbook that gave them for 1985, but noted that the readings change over time. I recently purchased a couple of maps that did not show any declination in the margins. Help !

 

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le V's method clearly will work, but it will only be as accurate as your compass.

 

I am somewhat surprised that your maps had no declination data in the margins. What was the scale of these maps? Were they USGS maps? Did they possibly have a compass rose imprinted somewhere on the map?

 

I am not aware of a web site that gives such information but I am sure such must exist.

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Did you know that the "North Star" (Polaris) moves with time? Albeit very slowly, but it does move. I have a hard copy that shows the position of Polaris with time and also has lines of declination for the CONUS (Continental United States).

 

For most major U.S. cities, try: www.timex.com/html/watch_inst_comp_DAUS.html

 

(Note: Jackson Mississippi is 1 deg East)(This message has been edited by acco40)

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There's another web site,

 

http://www.gislab.lanl.gov.faq.html

 

It has a map of the world, with declination degree lines on it as an overlay.

 

The best thing, though, is to make sure your map has complete margin info...can you get a refund?

 

BTW, a dec angle of 0 degrees obviously makes land navigation, and the teaching of it, much easier. Rumor has it that's why the Army located the Infantry Center at Ft. Benning, GA (yes, dec angle of 0 degrees)...

 

KS

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Actually what I meant to say was the annual change here in Juneau is a 13'E(minutes East) The "newest" USCGS topo maps here are from the mid 80's with more than a few still in print from the 70's! That is where my 5 degree change from the map came from.

 

Hydrographic (Ship) charts (maps) are printed more often and have the compass rose with the updated rate of change. They and Aeronautical charts also have information about Local Magnetic Disturbance area's. Got a few I know of that swing the needle of cruise ship navigation magnetic compasses up to 20 degrees out. They make for interesting looks on the faces of scouts trying to follow a bearing ;-)

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  • 4 months later...

I note that my new "toy" (a Garmin Mapquest 76S GPS system) gives declination information and can read out in either magnetic north or true north. Does anyone know how the GPS system determines declination? Is this something that updates over time, or is this something that was programmed into the unit at startup?

 

Bruce

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Hi All

 

>>Set your compass to N and aim it at Polaris (true North), the needle will then point to Mag North giving you your declination for your area.... <

 

That's pretty cool. Learn something new and fun everyday.

 

One other source may be your car owners manual. Some manuals provide declination for adjusting the compass in the car to the local area.

 

Have a great weekend.

 

Barry

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