Humminbird 786CI manual Glossary

Cross Track Error (XTE): Cross Track Erroris 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.

Differential GPS (DGPS): Differential GPS is a system to improve the position accuracy of the Department of Defense GPS thro ugh th e u se of secondary “correction signals” broadcast from ground stations around the coastal U nited States and on some inland waterways. These correction signals are provided by the USCG and received by an auxiliary Di fferential 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 To Go: Distance To Go is 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.

Estimated Position Error (EP E): Estimated Position Error is a ca lculation that indicates the potential position i naccuracy th e u ser m ay experience due to a variety of GPS factors which include satellite position in the sky, signal strength and others factors.

Fix Type: Fix Type indicates whether the GPS receiver is providing 2D fix or 3D fix. A 2D fix requires only three satellites andprovides only laitude and longitude. A 3D fix requires four or more satellites,and provides latitude, longitude and altitude.

GPS: GPS is a n acronym for Global Positioning System. GPS p rovides accurate position (latitude,longitude, altitude) information virtually anywhere on theearth through satellite technology and personal receivers on the ground. A ser ies of geosynchronous satellites broadcast a unique signal toward the earth once per second. A GPS receiver, such as that included with many Humminbird® products, receives the signals from these satellites and is able to determine position based on very slight differences in the time each signal is received and the receiver’s knowledge of the location of each of thesatellites.

Heading: Heading describes thedirection the boat is pointing and is measured in degrees (i.e. 321°, where 000° is North, 090° East, 180° is South, 270° is West). Due to wind and waves, the boat is often traveling in aslightly different direction than it is heading, a nd therefore Heading is o ften confused with Course Over Ground. See Course Over Ground.

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