3.4    BASIC OPERATIONS 
3ņ20 
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3.4.7    Suppress Rain/Snow Clutter [AUTO-RAIN] 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
When using the manual rain/snow clutter suppression function 
 
  Procedure    1  Control the rain/snow clutter returns on the radar display by turning the 
[AUTO-RAIN] control until targets can be easily observed. 
 
Turning [AUTO-RAIN] control clockwise suppresses rain/snow clutter returns. 
Turning [AUTO-RAIN] control counterclockwise intensifies rain/snow clutter returns. 
 
When the [AUTO-RAIN] control is turned clockwise, the rain/snow clutter suppression 
function suppresses rain/snow clutter returns and gets targets hidden by rain/snow clutter 
returns to appear on the radar display.    However, be careful that excessive suppression may 
cause small targets to be overlooked.    Since the rain/snow clutter suppression function also 
has the effect of suppressing sea clutter, the suppression efficiency improves when the 
[AUTO-RAIN] control is used with the [AUTO-SEA] control.    In general, turn the 
[AUTO-RAIN] control fully to the left. 
 
 
Using AUTO RAIN (automatic rain/snow clutter suppression function): 
 
Rain/snow clutter suppression can be performed in accordance with the level of rain/snow 
clutter.    Use this function when the clutter level changes with the direction. 
 
  Procedure    1  Press the [AUTO-RAIN] control. 
 
AUTO RAIN is selected, and RAIN    AUTO    is indicated at the lower left of the radar 
display.    Rotating the AUTO RAIN control and AUTO SEA control can make fine 
adjustments manually. 
 
 
Note:  When AUTO RAIN is selected, AUTO SEA is switched to the manual mode. 
AUTO SEA and AUTO RAIN cannot be selected at the same time. 
  Use the AUTO RAIN mode to set both the AUTO SEA and AUTO RAIN to automatic mode 
simultaneously. 
 
 
When  using  the  [AUTO  RAIN]  function,  never  set  the 
suppression  level  too  high  canceling  out  all  image 
noises from the rain or snow at the close range. 
Detection of not only echoes from the rain or snow but 
also  targets  such  as  other  ships  or  dangerous  objects 
will become inhibited. 
When  using  the  [AUTO  RAIN]  function,  make  sure  to 
choose the  most appropriate  image noise  suppression 
level.
 
Caution