GPS & Navigation Terms:

Acquisition Time The length of time that a GPS receiver typically takes to determine a position from at lea st three satelli tes. Hu mminbird® GPS rece ivers p rovide ver y fast acquisition times (underone minute), permitting users to get out on the water faster.

Altitude The height measurement above sea level. Altitude is a measurement that can be provided by GPS.

Bearing (BRG) The direction to a destination waypoint measured in degrees from North (i.e. 321°, where 000° is North, 090° East, 180° is South, 270° is West).

Chartplotter A navigation device that shows Present Position on a M ap, along with Tracks, Waypoints,and Routes. All Chartplotters are also considered Trackplotters.

Cold Start The procedure that a GPS r eceiver must perform when it d oes not have historical information egardingr its current location. This procedure typically lasts for several minutes, and may be experienced upon first power up of the receiver, or if the receiver has been moved a great distance.

Course Over Ground (COG) The current direction the boat is traveling measured in degrees from North (i.e. 321°, where 000°is North, 090° East, 180° is South, 270° is West). When the Course Over Ground is equal toBearing, the boat is said to be “On Course” and will arrive at the dest ination in the most efficient manner. COG is o ften confused with Heading. See Heading.

Cross Track Error (XTE) The straight-line distance of the boat from the intended Track. XTE measures how far the boat is off course and also triggers the Off Course Alarm. See

Track.

DifferentialGPS (DGP S) A system used to improve the p osition ac curacy of the Department of Defense GPS through the use of secondary “correction signals” broadcast from ground stations around the coastal United States and on some inland waterways. These correction signals are provided by the USCG and received by an auxiliary Differential Beacon Receiver (DBR) that connects to the GPS receiver. The advent of WAAS has largely negated the need for the added expense of a DBR in the United States.

Distance ToGo The straight-line distance between Present Position and the Destination Waypoint. DTG and SOG (Speed Over Ground) are used to calculate Time To Go. See Time

to Go and Speed Over Ground.

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Glossary