NorthStar MX500 Operator's & Installation Manual page 43

Route
calculated by the MX421 smart GPS antenna), Heading (HDG, your
NMEA 0183 compass input), and Heading To Steer (HTS) data on
the left side of the window. HTS data is calculated by considering
your Heading, minus COG and adding BRG to the waypoint. In
doing so, the software considers any Set to be included in the HDG
value. If there is no Set, your HDG should be equal to COG. Set and
Drift is calculated from GPS and your Speed Log (NMEA 0183 VHW
record or Pulse input) and Compass (NMEA 0183 HDM, HDT, or
VHW) input or an operator manual input.
On the right side of the lower left window you will find the Speed
Over Ground (SOG, calculated by MX421 smart GPS antenna), Speed
Log (LOG, the NMEA 0183 or pulse speed input), and the Waypoint
Closure Velocity (WCV). WCV reflects the real time velocity from
your present position and course towards the next waypoint. The
VMG and WCV are calculated from GPS data. Refer to the diagram
below to see a graphical representation between VMG and WCV.
Velocity Made Good:
Beginning
Wa ypoint
Waypoint Closure Velocity:
Beginning
Wa ypoint
Original Course Line
6297_01B.100
Version 3.0
Distance to
Waypoint Travelled
Effect of Set & Drift
Present
Position
SOG 13 Kn
Effect of
Set & Drift
Original Course Line
Present
Position
SOG 13 Kn
WCV 9 Kn
WCV is based on
Extended Course
Line (COG), SOG,
BRG & RNG to WPT
Operator's Manual
Next
Wa ypoint
BRG
Next
Wa ypoint
HTS to
counter
Set & Drift
29