Radar Cursor; Marpa Targets - NorthStar 972 Quickstart Manual And Reference Manual

Radar cursor

MARPA targets

Reference section 6 — Radar
96

Radar cursor

If you press the cursor pad while on the
radar screen, a radar cursor is displayed.
You can move the cursor to any echo or
other point on the screen and read the
The Miniature Automatic Radar Plotting
Aid (MARPA) target tracking system allows
you to designate displayed echoes as
targets, which will be tracked automati-
cally as they move. Each target's speed,
course-over-ground, closest point of
approach, etc. are calculated and displayed.
Targets are displayed on the radar image
with special symbols indicating their acqui-
sition status.
You can control how much data is
displayed for each target.
MARPA is used primarily for collision
avoidance in larger ships at ranges from
about 2 to 8 nautical miles, and in smaller
ships at ranges between 1/2 and 4 nautical
miles.
distance and bearing to it in the lower right
corner of the screen.
Press Vessel to remove the radar cursor
when done.
How does MARPA work?
MARPA works by continuously assessing a
target you have designated. As the vessel
pitches and rolls with the sea, the radar's
view, the target's shape and size, and the
ship's heading will all vary. If you can't see
the target on the radar, then the MARPA
feature can't see it either.
The 972 has built-in intelligence that
compensates for all this variation and
makes every attempt to track MARPA
targets — even in difficult conditions.
A critical component in the operation of
the MARPA feature is your heading sensor.
The heading sensor provides MARPA with
critical information to correlate the radar
display with the ship's heading. A poor
heading sensor can make MARPA a chal-
lenge even in good conditions.
Northstar 972