Advertisement
Auto\Last Height & Auto\Input Height – No Auto Height options are used by
the GPScard.
Note: Heights entered in the provided entry box must refer to the geoid (Mean
Sea level). In some other WinFrog dialog boxes, heights are displayed with
respect to the vehicle's selected zero vertical reference point.
Undulation Model:
The Undulation Model can be set to the Internal Table, which uses the NovAtel's
internal (OSU) geoid model, or Input Value in which case a specific Ellipsoid
separation value can be input. This Ellipsoid separation value is used to calculate
Ellipsoid height from the entered geoidal (Mean Sea Level) elevation, using the
following formula:
h = H + N
Unless you have accurate ellipsoid/geoid separation values from another source,
select the Internal Table radio button.
SV Tracking Elevation Cut Off:
Enter a mask angle value, in degrees. The GPSCard will not use measurements
from any satellites with elevation angles below the angular value input in the
Elevation (angle) Cut Off entry box.
DGPS:
This section of the dialog allows you to set the mode by which the GPSCard will
internally apply received differential GPS corrections.
There are four different DGPS modes: Auto, On, Off and Generate.
Auto: The GPSCard will automatically use differential corrections in its position
calculations, when available. If no corrections are available, the GPSCard will
compute a single point (aka autonomous) position solution.
On: The GPSCard will always attempt to use differential corrections. If no
corrections are available, no position will be computed.
Off: The GPSCard will not use differential corrections in its position
computations, even if they are available. Instead it will always compute a single
point GPS solution.
Generate: The GPSCard will generate differential corrections based on a fixed
reference position. This option is used for Base Stations only.
WinFrog User's Guide - Appendix C – GPS/NovAtel Con
Where:
h = Ellipsoid height (of the antenna)
H = MSL (ie geoid) height (of the antenna)
N = Geoid height (undulation)
Page 4 of 22
Advertisement
