Geometrics, Inc. G-822/G-823 Magnetometer Manual
6
sensor horizontally and at an angle to the flight path. In polar regions the sensor may be
mounted with its major axis tilted east or west to obtain the desired angle.
The maps in figures 4 and 5 may be used to determine the inclination and total intensity
of the Earth's magnetic field in the intended area of survey. This inclination information
should be used to adjust the sensor orientation for the best performance in the survey
area. The intensity information may be used as a check of the system operation.
In regard to sensor orientation, the Earth’s surface can be divided into three zones based
upon magnetic field inclination: a mid-latitude, equatorial, and polar. Within each of
these zones there is a particular sensor orientation that will yield adequate signal strength
over the entire zone. These regions and the corresponding sensor orientations
recommended for each region are shown in figures 6 through 9.
Figure 6. Mid-latitude zone.
The diagram to the left shows the
recommended sensor orientation
for operation in mid latitudes. This
zone is shown as the shaded
regions above and includes those
areas where the absolute
inclination of the Earth’s magnetic
field is greater or equal to 20º and
less than or equal to 75º. There are
no restrictions on the direction of
travel when using this sensor
orientation.
