Range-Gate-Pull-Off (RGPO) is a common type of electronic countermeasure (ECM) technique used to defeat or degrade tracking radars.The RGPO goal is to generate an ECM pulse that is a replica of the radar transmitted pulse with delay and amplification so as to pull the radar range gate off the target.Although a chi-square test algorithm for rejecting RGPO false targets has been proposed

it has low RGPO discrimination ratio and more error decisions in the absence of RGPO.To overcome its shortcomings

a new algorithm named as Chi + SLR + register is presented

which integrates the chi-square algorithm with a shift register and a signal likelihood ratio (SLR) test.This new algorithm has minimum probability of error decisions in specific length of shift register

and better performance than other algorithms in wide scope length of shift register.Additionally

the new algorithm is also effective in SOJ environment.