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Elevation:
If On is selected, the elevation determined by the GPS will be used as the elevation
of the antenna with respect to the WGS84 Ellipsoid. Do not enable this option unless
you are utilizing high accuracy (centimeter level) RTK type GPS positioning.
Accuracy:
The Accuracy value is the expected accuracy (i.e. standard deviation) of the
positioning device. This value is used in the weighting of this device relative to other
primary positioning devices, and in the vehicle's kalman filtering. The default values
should be changed only if you have confidence that newly entered accuracy values
are more correct than the default values.
You must also be cautious of setting both a Multi-Ref position and a single source
DGPS position as primary positioning devices. This will weight the single position
equal to the 5 positions combined to create the Multi-Ref position.
Code:
Set the Code to coincide with the code parameters that may be associated with the
GPS unit being used, as required when using telemetered GPS data. This is usually
set to 0.
Multiple Position Source Options:
This group box allows you to enable automatic switching of a secondary to primary
should the data from all POSITION and PSEUDORANGE data items set to primary
timeout. The Age entered is the length of time that the secondary will wait in the
absence of data from all primaries, before taking over as primary. This age is only
entered for the secondary.
For example, if the POSITION or PSEUDORANGE data items associated with two
GPS receivers were set to primary and the POSITION or PSEUDORANGE data
item of a third GPS receiver was set to secondary, both primary GPS receivers must
time out before the secondary will become the primary. Upon the recovery of either
of the original primary data items, the original primary will be reset to primary and the
original secondary will be reset to secondary.
Note for the auto switching feature to work, there must be at least one primary and
one secondary enabled. For example, given two data items, one set to primary with
the auto switching disabled and the other set to secondary with the auto switching
enabled, if the primary fails the secondary is not set to primary and the vehicle
positioning stops until the primary data item recovers.
Disable Auto Switching of Primary:
If this data item is not to be involved in the auto switching process, check this
box. As stated above, this data item is then not involved in the auto switching
process in any way.
WinFrog User's Guide - Appendix C – GPS/NovAtel Con
Page 7 of 22
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