NorthStar 961X Operation And Reference Manual page 362

Glossary
secondaries
sentence
waypoint
Page G-6
The "slave" loran transmitters in a chain of at least three sta-
tions.
A group of data in one of several formats defined by the
National Marine Electronics Association.
Speed Over Ground. The actual speed of your vessel relative to
SOG
the bottom of the water; that is, the speed your vessel is actu-
ally going.
SNR Signal-to-Noise Ratio. A guide number for determining the rel-
ative quality of GPS, DGPS, or loran signals as compared to
background radio noise.
TDs
Time Differences. The measured amount of time—in millionths
of a second—between those loran signals received from the
master and those from the secondary station. These measure-
ments are used to determine position, according to the
Loran-C system.
The vertical rise and fall of water caused by the gravitational
tide
pull of the moon and sun.
track A sequence of position measurements, or a desired line of
travel, defined one second at a time; that is, defined by actu-
ally travelling from point A to point B. Your track is a continu-
ous record of everywhere your vessel has been.
trip A sequence of waypoints, including past, active, and future
ones.
A particular location, defined by its lat/lon, distance and bear-
ing, or Loran-C TDs, which is used as an intermediate or final
destination.
XTE See cross-track error.
961 Operations and Reference Manual Rev. D