PNI TCM 5 - Manual (Page 27)

PNI Sensor Corporation Doc #1007537 r12
TCM3 & TCM5 User Manual – Sept 2012 Page 27
4.2.5 Declination Value
Declination, also called magnetic variation, is the difference between true and magnetic north, relative to
a point on the earth. It is measured in degrees east or west of true north. Correcting for declination is
accomplished by storing the correct declination angle, and then changing the heading reference from
magnetic north to true north. Declination angles vary throughout the world, and change very slowly over
time. For the greatest possible accuracy, go to the National Geophysical Data Center web page below to
get the declination angle based on your latitude and longitude:
http://www.ngdc.noaa.gov/geomagmodels/Declination.jsp