NavCom StarUtil-3000 Rev.A - Manual (Page 90)

StarUtil-3000 User Guide – Rev A
8-88
Solution Control
These messages set the navigation parameters for the receiver; i.e. satellite tracking limits,
aided navigation correction streams, constraint flags, etc. Although primarily used for Rover
navigation, the user may want to consider modifying certain parameters such as constraint
flags, and the minimum number of satellites to track for Base operation. Typically, enabling
WAAS dGPS mode helps to refine the base position when the Base position is unknown.
However, the conditions where this is not the case are important to remember. See this
warning
at beginning to this chapter for more information.
Solution Control is accomplished by several input parameters which are identified by the
following command messages:
[2DNAVMODE]
This command is used to enable or disable GPS navigation with height constrained (2D
navigation) and set the height constraint when the receiver computes a 2D navigation solution.
Use 2D navigation mode only when the height can be constrained accurately.
Otherwise, large errors may occur in the position solution.

Upper height limit imposed due to export limitations.
Examples: [2DNAVMODE]AUTO,0.0000
Commands the receiver to automatically transition between 3D (4 satellite
minimum) and 2D (3 satellite minimum) navigation. This can also be determined by
DOP values, even if 5 satellites are available. In 2D navigation, the last valid
computed height measurement is used.
[2DNAVMODE] ALWAYS, 10.5
Commands the receiver to switch to 2D (3 satellite) navigation and set 2D height to
10.5 meters. The receiver must compute an initial 3D navigation solution before it
transitions to 2D navigation. After 2D navigation is established, the receiver will not
transition back to 3D navigation.

The PVT tab/Navigation Status window displays the current nav mode and indication
of 3D or 2D navigation (see Figure 115).
[ANTENNAHIGHT]
This command is used to enable or disable the antenna height adjustment. This command
causes a response, which includes the [ANTENNAHEIGHT] mnemonic followed by the ON/OFF
setting. The [ANTENNAHEIGHT] parameters are {mode}, antenna phase center adjustment,
slant range of antenna body, and radius of antenna body.

The PVT tab/Antenna-Offset window displays the current [ANTENNAHEIGHT]
settings (see Figure 116).
[L1FALLBACK]
This command is typically set to OFF to disable the L1 fallback (or optimized shading) option.
When L1 fallback is ON, dGPS mode precedence is set to Dual 3D
 Single 3D  Dual 2D 
Single 2D.