Chapter 3    ADJUST THE RADAR ECHO 
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****FOR REFERENCE**** 
 
In order to obtain an accurate radar echo, sea clutter suppression adjustment and gain 
adjustment are essential. 
 
RAIN: Normally is set to “0”. But in the case of rain or snow, you need use the rain clutter 
suppression function to remove the noise appearing on the screen. 
 
GAIN: Adjust the GAIN to increase receiving sensitivity, then the radar observation range can 
be extended. If the sensitivity is set too high, the receiver noise is increase, and the contrast 
between the targets and the background video is reduced. As a result, the targets become 
obscure on the radar display. To observe densely crowded targets or short-range targets, 
adjust the GAIN to reduce the sensitivity so that the targets are easy to observe. However, be 
careful not to overlook important small targets. 
 
SEA:  SEA clutter suppression function can suppress the near range clutter noise. If the 
suitable adjustment is done, you can observe a clear target from short range to long range. 
 
When the automatic mode is selected for the rain/snow clutter suppression function, the sea 
clutter suppression function is switched to the manual mode. The sea clutter suppression 
function (AUTO) and the rain/snow suppression function (AUTO) cannot be selected at the 
same time. In addition, Please adjust the video in function (MANUAL) usually. Please attempt 
the function (AUTO) when the video adjustment of short-range cannot adjust by the bad 
weather. 
 
< ACTUAL OPERATION > 
Set RAIN clutter suppression level to 0. 
(1) Set RANGE to more than 6NM, and determine the target in the distance. The target 
location is far, and the targets as far possible can barely display is preferable. Set GAIN in 
order to observe the target clearly. 
(2) Change RANGE to 0.5NM, and set SEA clutter suppression level to observe the near 
target clearly. If you reduce the GAIN at this time, the target that was able to display at (1) will 
be not able to display, please note on the relation between the long range. 
(3) Since the rain/snow clutter suppression function also has the effect of suppressing sea 
clutter, the suppression efficiency improves when using with the [SEA] control. In general, 
RAIN clutter suppression level is set to “0”. But if you encounter a bad weather, set RAIN 
clutter suppression level to achieve better observation state.