NavCom StarUtil-2110 Rev.B - Manual (Page 21)

StarUtil-2110 User Guide – Rev. B
didn’t change. If any element of the position changes continuously during the
three second period then a 0xb1 solution is output 15 times.
9 Min SVs for Solution: Accept the default of 4 satellites, or enter a higher number. Four
satellites are the minimum SVs required for a 3D navigation solution, plus an acceptable
PDOP.
9 Max PDOP for Solution: The maximum PDOP value at which the receiver will compute
positions is 25.5. Enter the highest PDOP value according to application requirements. An
applied value above 25.5 reverts to the default of 10.0.
‡
The default setting for Max PDOP is 10. The quality of GPS data is dependent on
the geometry between the receiver and satellites; this includes the number of
satellites that can be "seen" by the receiver and the angle between the receiver
and satellites as a constellation seen by the receiver. A satellite near the horizon
usually provides a lower quality signal because of greater atmospheric
interference and the increased likelihood of the signal reflecting from surface
features; this is known as "multipath" error. The effect of geometry on GPS
quality is measured by PDOP (position dilution of precision). PDOP is the overall
measure of the precision obtainable with a given satellite geometry. For example,
a PDOP of 4 or less yields excellent precision, a PDOP between 5 and 7 is
acceptable and a PDOP of 7 or more is considered poor.
9 2D/3D Solution Mode: Click the Auto or Manual button to determine how height will be
applied to a 2D navigation solution.
• Auto: Sets the receiver to automatically transition between 3D (4 satellite) and 2D (3
satellite) 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.
• Manual: Enter the Height hold
value to set the receiver to 2D (3
satellite) navigation with the
Height hold value used for the
height measurement. 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.
‡
Click the icon in the toolbar
to view the current navigation
solution and other parameters of
message 0xB1. The 3D nav field
indicates if 3D navigation is
computed (see Figure 10).
Figure 10: B1 – Solution, 3D nav Field
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