Analysis of IPAR Field Performance

The Georgia Tech Engineering Experiment Station (GT/EES), under contract with the Naval Sea System Command (NAVSEA), has designed, developed, and field tested an Intrapulse Polarization Agile Radar (IPAR) system that pulse compresses on polarization modulation as opposed to the more standard techniques of phase or frequency modulation. The transmit waveform of the IPAR system is codd on a subpulse basis as either right (RC) or left (LC) circular polarization at rates of up 100 MHz. The transmitted code is recovered on receive by computing the sine of te relative phase angle between the horizontal and vertical components (sin ¿HV) of the received w3aveform. Thus, IPAR coding represents a binary coding scheme where RC corresponds to +1 and LC corresponds to ¿1 (by definition, a wave is RC polarized if ¿HV = +90° and LC polarized if ¿HV = ¿90°). A block diagram of the IPAR is carried in the relative phase between the H and V polarization components of the transmitted wave, this coding is independent pulse compress equally well with a narrowband, a frequency agile, or a wideband noise carrier. The narrowband source is at 9.5 GHz, the frequency agile sweeps through a bandwidth of 30 MHz at a 60 cycle rate, and the noise source has a spectral width of 140 MHz.