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2.9.1 HDOP
HDOP (Horizontal Dilution of Precision) selects the best positional
precision based on wider angular separation between the
satellites used to calculate a GPS unit’s position. This parameter is
influenced by obstructions such as nearby mountains or buildings.
The possible values the user can select are:
Values
< 1
< 2
>2
• <1 This is the best confidence level to be used for applications
demanding the highest possible precision at all times.
• Between 1 and 2 This is a good compromise between precision
and number of samples accepted (15m)
• > 2 Positional measurements could be used to make reliable in
route navigation suggestions (50-100m).
Depending on the selected value, the MSA will accept the
coordinates only if they are marked accordingly by the receiver.
Example if <1 is selected, the MSA will discard all the data provided
by the GPS receiver which are marked as HDOP>1. Vice versa, if > 2
is selected, the MSA will consider all the data coming in.
2.9.2 DGPS
Differential Global Positioning System (DGPS) is an enhancement
to GPS that provides improved location accuracy using ground
based stations that transmit a correction signal.
Values
ENABLED
DISABLED
Summary of Contents for MSA 340
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