JRC JMA-3400 Series, Instruction Manual, Page: 99 / 314

Chapter 3 ADJUST THE RADAR ECHO
51
3.5 SCREEN BRILLIANCE (BRILL)
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FOR REFERENCE
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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.
The brilliance level is displayed at the lower part of the screen when the BRILL
control is turned left or right.
Turning the control right increases the value, and turning it left decreases the
value.
About the BRILL control : please refer to the number 15 in Chapter 2.2.