Lowrance LRA-1800, Instruction Manual

Page: 40 / 48

34
North Up : a stabilized display mode in which North is at the top of the
radar display. This display mode requires a heading sensor.
Offset EBL : an electronic bearing line originating from a location other
than the PPI sweep origin.
Open Array Antenna : a radar antenna which has an external rotat-
ing scanner.
PPI (Plan Position Indicator) : The PPI provides a map-like repre-
sentation of target echoes.
Radar Overlay : radar image data laid over an electronic chart. This
feature requires a GPS position fix and a heading sensor. Radar Over-
lay is available only on GPS units and Sonar-GPS combo units.
Radome : a single housing containing a radar antenna and transceiver.
Rain Clutter : undesirable echoes caused by rain or snow.
Range : distance to a particular target.
Range Rings : fixed rings on the radar display designed to show the
distance from the antenna.
Sea Clutter : undesirable returns caused by smaller waves and water
movement.
Standby : radar mode that follows warm-up and precedes the start of
transmission.
Sweep Origin : the origin of EBL and VRM, the sweep origin is located
at the center of the PPI.
Target : an item detected by radar.
Time Base : line that rotates around the radar display, updating im-
ages on the display.
Tuning : intermediate frequency adjustment that enhances the per-
formance of the radar.
VRM (Variable Range Marker) : a range ring used to measure the
precise distance to a target, the variable range marker may be adjusted
to measure any distance within the radar's range.