The detection problem of dim signal is studied based on narrowband dual-polarization radar system.Firstly

the descriptions of Instantaneous Stokes sub-Vector Sequences (ISVS) of radar target echo and noise are presented and the statistics of suited distance between ISVS of random polarization EM wave and the anticipant signal are derived.Then

utilizing the suited distance difference between radar target echo and noise to the anticipant signal

a novel detection algorithm is presented through polarization and power accumulation and the radar detection performance can be obviously improved.It can be useful to anti-radar stealthy

early warning and space detection or other applications.