User Manual - ShipShop

♦♦♦♦♦♦♦User PointObject you place on the chart identified by its coordinates and displayed onthe screen with a reference symbol (see Mark, Waypoint).UTC = Universal Time CoordinatedTime scale based on the rotation of the earth that is used by most broadcasttime services.UTM = Universal Transverse MercatorMetric Grid system used on most large and intermediate scale land topographiccharts and maps.VariationAngle between the magnetic and geographic meridians at any place, expressedin degrees West or East to indicate the direction of magnetic North from trueNorth. It changes from point to point, and (at the same point) with time.VMG= Velocity Made GoodDestination closing Velocity. The VMG is calculated using the current speed ofthe vessel (SOG) and the difference between the current vessel course andthe bearing to the destination.WAAS = Wide Area Augmentation SystemThe Federal Aviation Administration (FAA), in cooperation with other DOT organizationsand DOD, is augmenting the GPS/SPS with a satellite-based augmentationsystem, the WAAS. It will provide a signal-in-space to WAAS users tosupport en route through precision approach navigation. After achieving initialoperational capability, the WAAS will then be incrementally improved over thenext years to expand the area of coverage, increase the availability of precisionapproaches, increase signal redundancy and reduce operational restrictions.WaypointAny point to which one intends to navigate. A sequence of Waypoints makesup a Route plan.♦ WGS-84 = World Geodetic System 1984Coordinates System or Datum developed by the Defence Mapping Agency(DMA). It is the default geodetic Datum used by the chart plotter and the GPS.♦♦♦Zoom-InShows more detail in a smaller area.Zoom-OutOperates similarly to zoom -in, but in the reverse, showing a wider but lessdetailed view.XTE = Cross Track ErrorDistance from the ship's present position to the closest point on a linebetween the origin and destinations Waypoints of the navigation.94 User Manual