Lecture11

# Lecture11 - Review Position Finding Geography 12 Maps and...

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1 Geography 12: Maps and Spatial Reasoning Lecture 11: Navigation: Route Selection Professor Keith Clarke Review: Position Finding • Environmental • Aids to Navigation – Map+ – Compass (declination) – Gyrocompass – Digital compass –GPS Grid, True and Magnetic North 6400 MILs to a circle Declination WEST TN MN 10 o W Magnetic north is 10 degrees west of true north To correct a map TRUE bearing (e.g. 30) to MAGNETIC , we need to rotate the map counterclockwise to correct So declination is ADDED to the magnetic bearing WEST IS BEST, SO ADD 30 + 10 = 40 For magnetic to true, do the opposite (SUBTRACT) 30 o

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2 Declination EAST TN MN 10 o E Magnetic north is 10 degrees east of true north To correct a map TRUE bearing (e.g. 30) to MAGNETIC ,we need to rotate the map clockwise to correct So declination is SUBTRACTED from the true bearing EAST IS LEAST, SO SUBTRACT 30 – 10 = 20 For magnetic to true, do the opposite (ADD) 30 o Quick solution Remember: 1. START WITH THE TRUE BEARING (map to compass) 2. WEST IS BEST ADD: EAST IS LEAST SUBTRACT 3. NOTE THAT YOU MAY GO OVER 360, IF SO JUST SUBTRACT 360 FROM RESULT 4. TO START WITH MAGNETIC NORTH BEARINGS, DO THE OPPOSITE Flight gyrocompass: Azimuths/10 For the Kiosk by Campbell Hall (34 24 58N 119 50 44W) Declination ?/?/1988 = 14 o E Declination 10/29/2008 =13° 15' E changing by 0° 5' W/year Declination 10/20/2010 =13° 03' E changing by 0° 5' W/year Declination 10/19/2011= 12° 57' E changing by 0° 5' W/year
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## This note was uploaded on 12/27/2011 for the course GEOG 12 taught by Professor Gautier during the Fall '08 term at UCSB.

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Lecture11 - Review Position Finding Geography 12 Maps and...

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