Instruction Manual

8 RA51/52/53/54/55 INSTRUCTION MANUAL – 05
STC (Sensitivity Time Control)
Since echo signals received by the radar are stronger when they are coming from a short distance,
it's difficult to compare signal strength between each reflected signal. To overcome this, signal
strength is adjusted in such a way that the received signal levels coming from a short distance are
lowered. This is helpful when there are large reflected waves from sea surfaces during rough
weather.
Fig.2-13 STC
FTC (Fast Time Constant)
When it rains or snows, fine noise may appear over the entire screen, making it difficult to identify
echoes. In such a case, echo images on the screen can be made easily distinguishable by adjusting
FTC.
Fig.2-14 FTC
PPI (Plan Position Indicator)
A display system of radar. Reflected radar signal is displayed in plan.
0.75
0.25
HU
STC OFF STC ON
0.75
0.25
HU
Echo is suppressed
around center
0.75
0.25
HU
FTC OFF FTC ON
0.75
0.25
HU
Small noises
are reduced.