JRC JMA-7710-6 Instruction Manual page 163

Target acquisition and tracking function with ATA are limited as follows:
[I] Resolution between adjacent targets and swapping during automatic tracking
Depending on the particular distance and echo size, resolution between adjacent targets during
automatic tracking usually ranges somewhere between 0.03 and 0.05 nm. If multiple targets
approach each other, resolution will become about 0.03 nm and this may cause the system to
regard them as one target and thus to swap them or lose part of them. Such swapping or loss of
targets may also occur if the picture of the target being tracked is affected by rain/snow clutter
returns or sea clutter returns or moves very close to land.
[II] Echo Intensity and Tracking Function
Echo intensity and tracking function are mutually related, and if no echo is detected for six
scans or more in succession, targets may be lost.
In such a case, it is necessary to help detecting targets by increasing radar gain. If radar gain is
increased too much, the radar may detect and track sea clutters and noises as targets and may
sound false alarms. In such a case, radar gain should be reduced and noises should be eliminated.
(The target to which 0 to 9 were appended is lost in over 200 scans.)
[III] Influence of Error Sources on Automatic Tracking
The [GAIN], [SEA] and [RAIN] controls on the radar should be properly adjusted so that targets
to be acquired and tracked are clearly displayed on the screen. Unless they are properly adjusted,
the tracking accuracy reliability will be reduced.
CAUTION
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