Filter
Top Products
103
Magnetic North. Humminbird® GPS units provide the option of selecting True or
Magnetic readouts by using the North Reference menu. See Magnetic North.
Present Position: Present Position is the current location (latitude, longitude)
determined by GPS. The Present Position is indicated on-screen by a directional boat icon
if the boat is moving, or a round symbol if the boat is stationary.
Route: A Route is series of waypoints linked together in a specific sequence to define
a navigation path between two points, and saved in the fishfinder’s memory. Routes
are often used when frequently traveling between two or more locations because it
is a faster and more accurate method than repeatedly selecting individual waypoints
each time one travels through the same area. Routes consist of a Start Waypoint, an
End Waypoint, and a series of waypoints in between. Users can begin navigation at
the beginning, the end (to run the route in reverse) or at any waypoint in between.
See Waypoint.
SD: SD is an acronym for Secure Digital. An SD card is virtually identical in function to an
MMC; however, the speed at which information can be accessed is generally faster, the
storage capacity is generally larger, and the card has security features which can be used
to prevent extracting the data from the card. SD is the same format that many digital
cameras use. See MMC.
Selective Availability: Selective Availability (SA) is a GPS system “feature” that can be
implemented by the U.S. Department of Defense (DoD) to degrade the accuracy of GPS
positioning information. With SA active, the GPS is accurate to within 100 meters 95%
of the time. With SA inactive, the GPS is accurate to within 45 meters 95% of the time.
Currently, SA is inactive and the consumer can enjoy the greater precision GPS provides;
however, the DoD reserves the right to activate SA at any time.
Speed Over Ground (SOG): Speed Over Ground is the measurement of the boat’s
progress across a given distance, and is the speed measurement provided by GPS. An
alternate, Speed Through Water, is provided by a speed paddlewheel, and is the
measurement of the flow past the boat, which may vary depending on current speed
and direction. Speed Over Ground is optimal for navigation because accurate
destination times can be derived from this measurement. Humminbird® products allow
for input and display of both speed measurements.
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.