Abstract: Under the consideration of polarization,the angle measurement mathematical model of phase-interferometer PRS tracing coherent dual sources is presented.Several key factors including the polarization of radar,decoy and receiving antenna were taken into account,and their effects on passive-radar-seeker(PRS)angle measurement performance are also analyzed.The polarization condition for PRS to trace radar or decoy is determined,and the Poincare sphere is finally introduced to describe the relationship between polarization and PRS pointing.The enhanced performance of discrimination between radar and coherent decoys is validated by simulation,which could provide a basis for the application of polarization information in PRS.