5─1 
Usage of ATA 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
There are the following limitations on use of the target acquisition and 
tracking functions of ATA. 
 
  [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 to 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 less 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]  Intensity of echoes and the tracking function 
  The intensity of echoes and the tracking function have a correlationship, 
and thus the target will be lost if no echoes are detected during six 
scans in succession.    If a lost target exists, therefore, radar gain must 
be increased to support detection of the target. If, however, radar gain is 
increased too significantly, sea clutter returns or other noise may be 
erroneously detected and tracked as a target, and resultingly, a false 
alarm may be issued.   
 
[III]  Adverse effects of error sources on automatic tracking 
  To execute accurate tracking, it becomes necessary first to appropriately 
adjust the [GAIN], [SEA] and [RAIN] controls of the radar so that the 
target to be acquired and tracked id clearly displayed on the radar 
display.  Inappropriate settings of these controls reduce the 
reliability/accuracy of automatic tracking. 
Attention