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On: WinFrog will always attempt to use differential corrections. If no corrections
are available, no position will be computed.
Off: WinFrog 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: WinFrog will generate differential corrections based on a fixed
reference position. This option is used for Base Stations only.
Phase Smoothing:
Phase smoothing utilizes the GPS receiver's observations of the GPS satellite's
carrier signals. Because the GPS L1 frequency has a wavelength of only 19 cm.,
measurements made using this signal will provide higher accuracy than
measurements made on the C/A code message modulated onto the L1 signal. Note,
however, that since the carrier phase position is derived from the C/A code position,
it does not offer an improvement in precision.
If the Phase Smoothing feature is enabled, WinFrog will use the C/A Code derived
(DGPS corrected) position to derive the number of L1 wavelengths to each of the
observed satellites. Over the length of time entered into the Filter Length field
(value in seconds), WinFrog will switch the GPS calculated position from the C/A
code position to the derived Carrier Phase position.
WinFrog will continue to use the carrier phase data to provide positioning until the
Cycle Slip Tolerance is exceeded. A Cycle Slip is the loss of lock on a satellite's
signal. This loss of lock forces WinFrog to re-establish the number of wavelengths
from the antenna to the satellite. If the number of cycle slips exceeds the Cycle Slip
Tolerance, WinFrog will resort back to the C/A code position and re-calculate the
number of wavelengths to all received satellites.
Graphics:
Select the On radio button to display a labeled square in the Graphics and Bird's
Eye displays depicting the raw (unfiltered) location of the GPS antenna. This
provides a means of comparing raw and filtered positions between different sources.
Display:
The selection made here determines which type of information will be displayed in
WinFrog's Calculations window (when the GPS Pseudorange device is turned on for
display in that window). Select from the three provided options:
Results – The Calculations window will show the results of the GPS
Calculations, including the Multi-Ref position and all individual solutions.
Data - The Calculations window will show the results of the GPS Calculations,
including the Multi-Ref position and data related to each individual carrier phase
solution (when Phase Smoothing is enabled).
WinFrog User's Guide - Appendix C – GPS/NovAtel Con
Page 12 of 22
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