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Latitude and Longitude
• The earth is gridded by imaginary lines called:– Longitude– Latitude
Building 16-105 @ Highline CC
• Latitude = 47.389806• Longitude = 122.299408
• http://itouchmap.com/latlong.html
Length of a degree of Longitude
• The length of a degree of longitude decreases as you travel from the equator to the north or south pole.
• Seattle: 1˚ ≈ 47 miles
Length of a degree of Latitude
• Parallels are constructed approximately the same distance apart.
• Seattle: Seattle: 1˚ ≈ 69 miles
Distances
• Your text book covers finding the distance between to locations.
• Remember: The earth can be approximated as a sphere.
Direction
• The angular relation of one line to another– Measured in Degrees– A complete circle is equal to 360˚
Degrees….not base10
• 360˚ = complete circle• 1˚ = 60’ = 60 minutes• 60’ = 60” = 60 seconds
• For example: 50˚30’45”
Calculations
• Converting from decimal degrees to degree/minutes/seconds.
• Adding Angles• Subtracting Angles– borrowing
Magnetic Declination
• The meridian indicated by the needle on a compass seldom coincides with the true meridian.
• http://www.ngdc.noaa.gov/geomag/declination.shtml