PURPOSE: To remove or diminish step by step clutters contained in radar reception signals by storing previously computed algorithm in a memory with high capacity and sending out the results quickly by operating adjustment knobs.

CONSTITUTION: When any one of adjustment knobs is selected, a functional adjustment signal is latched by a clutter algorithm memory 29 through a port selecting apparatus 31. At that time, one 8 bit data stored in the memory is analog-converted by a D/A converter 44 through a data distributor 28. The resultant signal passes a function amplifier 45 and a function converter 46, is compared with the pulse repeated time PRT temporally received by a surface reflected wave removing apparatus 47, and diminishes the surface reflected waves from PRT video signals. Various kinds of algorithms can be replaced by exchanging a high speed memory and stages of sampling for removal of clutter comprise 2 to 512 stages, so that the obtained clutter removing apparatus can be employed for a color display and the detecting and capturing functions are improved.