Product Manual

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 Elev. Mask: displays the current elevation mask. This is the
minimum angle above the horizon that a satellite must be located
before it is used and is represented on the sky plot by a red
circle. This setting is useful when using the GPS in areas where
there might be obstructions to the view of low flying satellites
(e.g. around buildings or trees). A typical elevation mask setting
is between 5 and 15 degrees to eliminate those satellites from
being used to calculate a position. The purpose for this setting is
to increase the accuracy of the GPS. However, by using this
setting, you are reducing the total number of satellites that can be
tracked and used by your Nomad GPS receiver. The idea is to
eliminate those satellites that may degrade the accuracy of your
Nomad GPS receiver. This is configured in the Masks section of
the GPS page.
 Masks: Displays the current PDOP and HDOP mask values as
configured in the Masks section of the GPS page. If the
measured Dilution of Precision (DOP) value exceeds the value
set for the corresponding mask, the resulting calculated position
will be ignored. In general, as the value of the DOP decreases,
the accuracy of the GPS position increases. DOP values greater
than six usually indicate the GPS position data is of poor quality
(due to poor satellite geometry) and the resulting positions are
less accurate. NOTE: DOPs can not be displayed in Binary
Mode, however, the DOP masks are still in effect.
Satellite Icons
 Unused: A GPS satellite whose signal is being received, but not
being used for position calculations.
 Used: A GPS satellite that is being used to calculate your current
position.
 SBAS: A Satellite Based Augmentation System (SBAS)
satellite, which can be used for error corrections. (See the DGPS
page for more information.)
Leave SNR trails: Creates a dot on the screen for all previous satellite
positions that form a trail on the sky plot over time as the satellite
moves across the sky.