Figure 4
Figure 2
1.9
1.10
1.7
1.8
1.7 UTM Roamer Scales (Fig 2)
The Universal Transverse Mercator (UTM) grid roamer scales, located on the clear base, are for
position measurements.
1.8 GPS 100 Meter Confidence Circles (Fig 2)
On a map, the appropriate scaled confidence circle drawn around an approximate GPS position,
indicates your actual position will be within the 100 meter circle, 95% of the time.
1.9 Magnetic Declination Scale (Fig 2)
Adjust for magnetic declination by turning the vial until the arrow on the
blue
orienting circle points to
the magnetic declination angle, at your position.
1.10 Reversible Ruler System (Fig 2)
The Eclipse 8096 provides a reversible ruler for measurements in inches or centimeters.
2 -- Magnetic Declination
Magnetic declination is the difference between true geographic north (north pole) and magnetic north
(in northern Canada), with respect to your position. It is important to note magnetic declination at your
position, because magnetic declination varies and fluctuates slowly, at different rates around the world.
Use the Isogonic Chart (Fig 3, p 3), or current United States Geological
Survey (USGS), Bureau of Land Management (BLM), or another map
to determine magnetic declination at your position. Declination can be
east, west, or 0
o
at your current position. Zero degrees declination
indicates true and magnetic north are aligned.
Example: If magnetic declination at your position is
15
o
east
, magnetic
north is 15
o
east of true north. Figure 4 displays true north and
magnetic north, as indicated by a USGS or BLM map in a specific area.
Most maps and all GPS receivers use true geographic north as a
reference. When adjustment for magnetic declination is complete, a
compass bearing will be with respect to
true
north , same as the map,
or GPS receiver.
2
