| 摘要 |
<p>PURPOSE:To select a filter shape automatically by comparing output data from the filter with a reference amplitude of a target level. CONSTITUTION:An amplitude comparator 6 compares output data from the filter with a reference amplitude of target level and selects the filter shape automatically. Upon input of large clutter through an A/D converter, a prestage filter produces an output higher than an amplitude stored in a reference amplitude memory 7. Count of a counter 9 increases every time when a comparator 8 produces an output '1'. When the count of the counter 9 exceeds a predetermined value, a comparator 10 produces an output '1'. When the comparator 10 produces an output '1', a filter shape selecting circuit 11 selects a filter shape in which the clutter is suppressed more. Filter shape thus selected is set in a filter through an indicator and a filer shape memory in order to realize processing with high clutter suppressing performance.</p> |
