Humminbird 1155C - Manual (Page 125)

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Glossary
Acquisition Time: The length of time that a GPS receiver typically takes to determine a position from at
least three satellites. Humminbird® GPS receivers provide very fast acquisition times (under one minute),
permitting users to get out on the water faster.
Alarm, Arrival: The audible alert that sounds when the boat is equal to or less than the alarm setting (25
feet – 3000 feet) from the location of the destination waypoint.
Alarm, Drift: Drift Alarm is an audible alert that sounds when the boat is equal to or over the alarm setting
(25 feet – 3000 feet) from the location where the alarm was turned on.
Alarm, Off-Course: Off-Course Alarm is an audible alert that sounds when the boat’s distance from the
intended Track, (Cross Track Error), is equal to or over the alarm setting (25 feet – 3000 feet). See Track
and Cross Track Error.
Altitude: Altitude measures height above sea level. Altitude is a measurement that can be provided by
GPS.
Bearing (BRG): Bearing is 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: Chartplotter describes a navigation device that shows Present Position on a Map, along with
Tracks, Waypoints, and Routes. All Chartplotters are also considered Trackplotters. All Humminbird® GPS
Combo units are Chartplotters. See Trackplotter.
Cold Start: Cold Start refers to the procedure that a GPS receiver must perform when it does not have
historical information regarding 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): Course Over Ground is 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 to Bearing, the boat is said to be “On Course” and will arrive at the
destination in the most efficient manner. COG is often confused with Heading. See Heading.
Cross Track Error (XTE): Cross Track Error is 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 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 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.