Appendix D - Glossary - NorthStar 958 Operator's Manual

Appendix D - Glossary

accuracy absolute accuracy—the accuracy of displayed lat/lon
coordinates of your present position as compared to true lat/
lon determined from a chart or other reference source.
repeatable accuracy—the ability to return to the same location
using a receiver's previously-obtained coordinates.
acquisition The procedure—and the time it takes—during which a GPS
receiver tries to track satellites, but before it actually computes
a position fix.
Data describing the precise orbits of GPS satellites, obtained
almanac
automatically from satellite signals and stored in a GPS
receiver. The first time the receiver is turned on, it requires
about 15 minutes to collect almanac data. Thereafter, it
usually can use the almanac data previously collected.
Avoidance point A waypoint that you enter into the database and define by its
radius and either its lat/lon, or loran TDs, or distance and
bearing. It indicates an area into which you specifically want
to avoid navigating.
beacon
A radio transmitter, operated by the U.S. Coast Guard, which
supplies differential corrections to GPS receivers.
bearing
The magnetic course from your present position to a waypoint.
cartography
The art or technique of making maps or charts.
chain
A group of loran transmitters comprising a master station and
at least two secondaries.
COG
Course Over Ground. The actual path of your vessel relative to
the surface of the earth; that is, the direction your vessel is
actually moving.
coordinates
A position defined by either latitude and longitude; TDs; or
distance and bearing. The positions of lat/lon and TDs are
referred to as absolute, and distance and bearing are relative
(that is, distance and bearing are in relation to a certain
reference point).
958 Operator's Manual, Rev. A Page 205