Filtering Rain Clouds Ftc - Raytheon NSC 18 User Manual

2.3.1.6

Filtering rain clouds FTC

Step 1
Step 2
Step 2
FTC is responsible for differentiation or filtering of rain clouds. Advance the FTC
control slowly (remember the 3 scans) until only the leading edges of the rain clutter
are visible. As the FTC is increased, weaker returns will reappear. Stronger returns
will begin to reduce in the visible area. The best setting will be a balance between
restoration of weaker returns and adequate size of the stronger returns.
Use the trackball to place the cursor on the slider then press the upper trackball.
Rotate the trackball to increase or decrease the amount of FTC.
Adjusting the FTC will also reduce the land echoes and thin out larger targets.
With FTC on and in a light sea, it is possible to overcompensate with the SEA
control; if so, with FTC ON a false noise ring may be displayed.
Too much FTC will shorten or delete RACON responses.
2.3.1.7 CFAR
Step 1
AUTO
When AUTO is activated, the slider symbols for SEA, RAIN and FTC are hidden
and the bar color changes to yellow.
This AUTO mode activates the CFAR (Constant Fault Alarm Rate) functionality.
CFAR describes a control algorithm, which uses the evaluation of echoes to
calculate statistical average values for SEA, RAIN and FTC.
These average values are used for optimization of the radar video.
Use of CFAR simplifies radar video optimization. However, depending on
the weather conditions misinterpretations are possible.
In case of doubt, switch to MANUAL compensation for SEA, RAIN and
FTC to clarify the situation. RACONs are best seen in MANUAL.
3748DOC020102
Operator Manual
Step 1
Select MANual mode
Step 1
NOTE
2−30
Edition: 14.JAN.2005