Northrop Grumman Sperry Marine VisionMaster FT, User Manual

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Radar/Chart Radar User Guide Glossary
65900010 Glossary-1
Glossary
A
Activated Target: A symbol representing the automatic or manual
activation of a sleeping target for the display of additional
graphically presented information including: a vector (speed and
course over ground); the heading; and ROT or direction of turn
indication (if available) to display actually initiated course changes.
AFC: Automatic Frequency Control (fine tuning)
AIS: Automatic Identification System. A system capability which enables
ships and shore stations to obtain identifying and navigation
information about other ships at sea, using an automated
transponder.
Antenna: Slotted waveguide array for transmitting and receiving
microwave signals. 10cm S-band (9 or 12ft aperture) or 3cm X-
band (4, 6 or 8 ft aperture).
Anti-clutter: Removal of unwanted reflections on the radar screen caused
by rain, sleet etc. (see Clutter).
ARCS: Admiralty Raster Chart Service. A service of British Admiralty,
suppliers of electronic charts with world coverage, in the HCRF
data format.
ARPA: Automatic Radar Plotting Aid – a system wherein radar targets are
automatically acquired and tracked and collision situations
computer assessed and warnings given.
ATON: Aid To Navigation (AIS nav symbol).
AZ: Acquisition Zone
Azimuth (AZ): The number of degrees from North (or other reference
direction) that a line runs, measured clockwise.