From a pixel array where imaging pixels are arranged, pixel signals of respective columns on a selected row are read in parallel in a horizontal blanking period of a horizontal period. The entropy of the filtered data sequence is determined and peaks are detected in the entropy data sequence. The system operates multi-statically and as an incoming projectile enters the illuminated region, reflected energy from one or more illuminators is detected by one or more displaced RF receivers. Each flight block includes a tool holder, having a generally rectangular body, removably mounted within the slot. At least the data of the selected physical block being valid is copied into the erased physical block.