Research Of Pulse Radar Based On Polarization Encoding Technique

In order to meet more performance requirements in polarization radar systems,the polarization encoding technique is getting more and more attention. Utilizingpolarization encoding technology, the optimal design of radar signal waveform canbe acheived, which effectively improves the overall performance of radar system.What’s more, the radar signal can be designed orthogonally to fulfill completedection of the target polarization scattering properties within one observation cycle.Firstly, the paper makes discussions and researches on polarization encodingmodulation and demodulation technology, with three kinds of combination radarsignal about polarization encoding introduced. They are polarization codingfrequency hopping signal, polarization encoding-linear frequency modulation pulsecompression signal and polarization-phase coded signal respectively. And the mainfocuses therein are radar signal waveforms which are designed through the phaseencoding and polarization encoding method. Adding in the polarization codingtechnology, the phase coding pulse compression signal compensates for the dopplersensitive disadvantage and improves the radar signal detection performace greatly.Combined with the simulation results, the influence factors of the polarizationencoding pulse compression detection performance are researched. And thecorresponding influence rules and conclusions are obtained, along with advantagescaused by polarization coding technique for the phase code pulse compression signalvalidated.The multi-user interference problem which is similar to that in thecommunication system may emerge when applying polarization encoding radarsignal in correlation detection. The co-channel interference sourcing from otherradar signals also exists. In that case, the paper draws lessons from the theory of PNcode synchronization capture and track in communication systems. The local phasecode and polarization code in sequence will be matched synchronously with thesignal, taking advantage of the correlation property of pseudo-random code. Thesimuilation analysis verifies the valid avoidance of multi-user inference encoded bydifferent polarization codes.For the aspect of adopting the polarization encoding in the target polarizationmeasurement, the paper makes researches on the scattering matrix measurement.The measuring methods based on fuzzy function matrix inversion and thefrequency-domain estimation algorithm on the basis of the discrete time fouriertransform(DTFT), are mainly analyzed theoretically. From the theoretical analysisand simulation results, the effectiveness of the two algorithms is confirmed. And the influence rules of the factors such as signal-to-noise ratio are comparied between thetwo methods. Meanwhile, the validity of polarization meusurements when adoptingpolarization encoding radar signals is verified.