Onwa Marine Electronics KR-1338C v.1 - Manual (Page 18)

The range and bearing of a target is displayed on what is called a Plan Position
Indicator (PPI). This display is essentially a polar diagram, with the transmitting
ship's position at the center. Images of target echoes are received and displayed
at their relative bearings, and at their distance from the PPI center. With a
continuous display of the images of targets, the motion of the transmitting ship
1.6 The Radar Display
Own ship
(radar)
(A) Bird's eye view of situation (B) Radar picture of (A)
Own ship
in center
Targets
Heading line
Range and bearing of
a target, relative to own
ship, are readable on
the PPI
Figure 1-1 How radar works
is also displayed.
10