Electronic counter-countermeasures system

Claim 1

A radar system utilizing a cathode ray tube for a polar coordinate display wherein said cathode ray tube comprises: means for visually indicating the presence of a desired target; means for determining the range and azimuth of said desired target in the presence of radar jamming signals; said target indicating and range and azimuth determining means comprising an electron energy source, a first luminescent screen of wholly short persistence phosphorus material so disposed as to be activated by said electron energy source to fluoresce in a first color and emit ultraviolet energy rays, a second luminescent screen of wholly long persistence phosphorus material positioned in a cascade relationship with respect to said first screen and so disposed as to be activated by said ultraviolet energy rays to fluoresce in a second color distinct from said first color when the energy of the ultraviolet rays exceeds a minimum intensity and barrier means separating said cascaded first and second screens for permitting the passage of ultraviolet and other light energies and for barring the passage of electron energy such that radar jamming signals are visually displayed in said first color and the desired target signal is visually displayed in another distinctive color which is the result of a mixture of said first and said second colors.