Campbell Scientific RAWS-P Remote Automated Weather Station - Manual (Page 32)

RAWS-P Remote Automated Weather Station
9.2 USGS Web Calculator
The USGS provides an easy way of determining the declination of a specific
site. Since magnetic declination fluctuates with time, it should be adjusted
each time the wind sensor orientation is adjusted. The calculator can be
accessed at:
www.ngdc.noaa.gov/geomagmodels/Declination.jsp . FIGURE 9-4
shows an example for Logan, UT.
FIGURE 9-4. USGS web calculator
In the example above the declination for Logan, UT is 12º 24 ′ or 12.4º. As
shown in FIGURE 9-4, the declination for Utah is east (positive), so True
North for this site is 360 ─ 12.4 = 347.6 degrees. The annual change is 7
minutes west per year or ─7 minutes/year.
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