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Glossary
GPS and Navigation Terms
Time To Go (TTG):
Time To Go is the estimated time required to reach the destination waypoint. TTG is calculated using
the SOG and DTG. See
SOG
and
DTG
.
Track:
A Track is a series of saved points that define the past path of the boat. These Track Points are saved at regular
time intervals. Tracks are a useful and quick method to see where you’ve been, and an easy guide to follow to get you
back to the starting point. Generally, all GPS units have a limited number of Track Points that can be saved before the
unit runs out of memory and begins erasing the first track points saved. Because of this, the user can adjust the Track
Point Interval menu to increase the amount of time between when points are saved, and thus extend the distance
covered by a track. Tracks can also be permanently saved to memory, and re-displayed at the user’s option.
Track Line (TRK):
The Track Line is the desired line of travel between two waypoints, and represents the most efficient
path between the two points because it is a straight line. The TRK is measured in degrees (i.e. 321°, where 000° is
North, 090° East, 180° is South, 270° is West). See
Cross Track Error
and
Course Over Ground
.
Trackplotter:
Trackplotter describes a navigation device that shows Present Position, along with Track, Waypoint, and
Routes, but NO MAP in the background. See
Chartplotter
.
Trolling Grid:
Trolling Grid is a Humminbird® feature that displays a precise reference grid around a waypoint. This grid
is used as a guide pattern for trolling around a specific area to assure a more efficient and complete coverage of that
area. Trolling Grid resolution be changed by zooming in or out on the chart. The Trolling Grid can also be rotated on the
display to orient it for optimal boat course for wave and wind conditions.
UTC:
UTC is an acronym for Universal Time Constant. UTC is the “standard time” used in navigation, and is the local
time in Greenwich England. (UTC is equivalent to Greenwich Mean Time (GMT)). To display the correct Local Time in a
Humminbird® GPS unit, the user must use the Local Time Zone menu and select the time zone (i.e. EST, CST).
WAAS:
WAAS is an acronym for Wide Area Augmentation System. WAAS is complementary technology to GPS that
provides enhanced accuracy through correction signals broadcast from Federal Aviation Administration WAAS satellites
stationed over the USA. These secondary signals are automatically received by the standard Humminbird® GPS Receiver.
With WAAS signal, GPS accuracy is improved to within 3 meters 95% of the time. Outside the United States, regional
governmental coalitions have created similar systems such as EGNOS (Europe) and MSAS (Japan).
Waypoint:
A Waypoint is the saved location (latitude, longitude) of a point of interest that is stored in a GPS receiver’s
memory. This can include a marker buoy, dock, fishing hole or anywhere else the user may want to return to.
Humminbird® products offer the ability to name and assign a symbol to the saved location. Depth, Date and Time of Day
when the waypoint was created is also saved.
Waypoint Target:
Waypoint Target is a Humminbird® feature that displays a precise “bull’s eye” around a selected
waypoint. This bull’s eye is used to easily monitor boat position relative to a waypoint, and is useful for fishing over
submerged structure. With Waypoint Targets, a quick look at the screen lets you know how far off the waypoint the boat
has drifted.
