NavCom StarUtil-3000 Rev.A - Manual (Page 100)

StarUtil-3000 User Guide – Rev A
Velocity
The Velocity window provides the vectors for position velocity, East, North, and Up, in meters
per second (see Figure 118). The Ground Speed and Ground Track are the speed over ground
and direction of travel (true, not magnetic), which are displayed on the Dashboard graphically
(see Figure 113).

Velocity North, East, and Up are data items in the PVT1B message. Refer to the
Sapphire Technical Reference Manual for details (see Related Documents in the
fore-matter).
Figure 118: PVT Tab – Velocity Window
Error Estimates
Figure 119: PVT Tab – Error Estimates Window
 Position FOM: The position Figure Of Merit is the estimated uncertainty in the navigation
solution. FOM is the same as the One sigma error estimate. Refer to the Sapphire Technical
Reference Manual (see Related Documents in the fore-matter).
 Time FOM: 10x TDOP
 DOP: Dilution of Precision. A class of measures of the magnitude of error in GPS position
fixes due to the orientation of the GPS satellites with respect to the GPS receiver. There are
several DOPs to measure different components of the error: GDOP (Position and Time),
PDOP (Dimensional Position), HDOP (Horizontal Position), VDOP (Vertical Position), and
TDOP (Time).
 Refer to Chapter 6 User Profiles/ [PDOPLIMIT] for additional information.
 NORTH/EAST/UP: The vectors for position velocity.
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