NorthStar 957 Operator's Manual page 186

course-up
coverage
cross-track error
cursor
DGPS
ephemeris
great circle
Page 178
An orientation on the chart screen in which the viewing angle
matches your true course during the last few seconds, as
determined by the GPS receiver.
The extent to which a geographical area is encompassed by
usable GPS or loran signals.
The difference between your desired track and your actual
track; that is, how far off you are from your intended course
line.
The display panel indicator that shows which character or
character field is ready to be changed, acknowledged, or
entered by the user. It's activated and positioned by the user
when required. The 957's cursor appears as an arrow or a
flashing block, depending on whether you're choosing or
entering data. Also known as the red circle on the CHART
screen, which you manually activate and position.
Differential Global Positioning System. A technique developed
by the U.S. Coast Guard for correcting basic GPS position to
increase its accuracy from 20-30 meters (65-100 feet) to 1-3
meters (3-9 feet).
Data used to calculate exact satellite positions, continually
updated and derived from information relayed to the 957 in
each satellite's data stream.
ETA
Estimated Time of Arrival at the next waypoint, as calculated
by the 957 according to your present speed of advance (SOA)
and distance to the waypoint.
ETE
Estimated Time Enroute to the next waypoint, as calculated by
the 957 according to your present speed of advance (SOA) and
distance to the waypoint.
GPS
Global Positioning System. A navigation system using signals
from earth-orbiting satellites. The system is capable of
providing high accuracy under all weather conditions.
Shortest possible path between two points on the surface of a
sphere.
GRI
Group Repetition Interval. The characteristic identifying
period of signals emitted by each loran transmitting chain. The
957 Operator's Manual, Rev. B