초록 ▼

The radar radiates, alternately or according to a given code, left-hand and right-hand circularly or elliptically polarized signals. At the receiving end, the two orthogonal polarized components of the received signal are processed separately, and the phase shift between the two components is measur

The radar radiates, alternately or according to a given code, left-hand and right-hand circularly or elliptically polarized signals. At the receiving end, the two orthogonal polarized components of the received signal are processed separately, and the phase shift between the two components is measured. It is determined whether this phase shift is similar to that existing at the instant of transmission between the two orthogonally polarized components which are mixed to produce the circularly or elliptically polarized signal. The similarity check is made by correlation. A desired target is indicated if there is a given similarity. Coherent signal processing is not necessary (but possible).

대표청구항 ▼

A radar system for discriminating among targets on the basis of echo polarization characteristics, comprising: transmitting means for radiating elliptically polarized signals switched between left and right hand sense according to a predetermined pattern; said transmitting means including an antenna

A radar system for discriminating among targets on the basis of echo polarization characteristics, comprising: transmitting means for radiating elliptically polarized signals switched between left and right hand sense according to a predetermined pattern; said transmitting means including an antenna having two orthogonal radiating modes and means for generating a pair of mutually orthogonally phased RF signals exciting said antenna to radiate elliptically polarized waves; receiving means responsive to echo signals from targets illuminated by said transmitting means, said receiving means separating said echo signals into first and second components having a mutual phase difference therebetween as a function of their relative polarization angle in said echo signals; and means for evaluating said phase shift extant between said first and second echo signal components compared to that of said pair of RF signals generated in said transmitted means to provide a signal indicative of polarization correspondence.