ashtech DG14, Reference Manual

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36 DG14 and DG16 Board & Sensor Reference Manual
most recently saved during the startup. If parameter settings were not saved, the
receiver uses the default settings at startup.
The DG16 can perform position computations and navigation solutions in several
position modes and eight dynamic modes.
Position Modes (Least Squares Algorithm)
Use the $PASHS,PMD command allows you to set the position mode. See “PMD:
Position Mode” section on page 138 for more information.
• Position Mode 0
At least four satellites at elevations equal to or above the position
elevation mask are needed to compute a position. The receiver stops
computing positions if the number of satellites tracked falls below three. All
three polar coordinates (latitude, longitude, altitude) are computed in this
mode.
• Position Mode 1 (Default)
At least three satellites with elevation equal to or above the position
elevation mask are needed to compute a position. Only the latitude and
the longitude are computed if three satellites are locked and the altitude is
held fixed. For more information on fixed altitude modes, see ”Fixed
Altitude Modes” on page 40. The receiver stops computing positions if the
number of satellites tracked falls below three. All three polar coordinates
are computed if more than three satellites are locked.
• Position Mode 2
At least three satellites with elevation equal to or above the position
elevation mask are needed to compute a position. Only the latitude and
the longitude are computed and altitude is always held fixed even if the
receiver is tracking more than three satellites. The receiver stops
computing positions if the number of satellites tracked falls below three.
• Position Mode 3
At least three satellites with elevation equal to or above the position
elevation mask are needed to compute a position. Only the latitude and
CAUTION
User-entered parameters will be lost and default settings will be restored if
the command $PASHS,SAV,Y is not entered before the next power cycle.