Research Of Passive Radar Imaging Technique Based On Single External Illuminator And Multiple Receivers Mode

Recently one of research interesting on new style radar system is focus on the passive radar system using opportunity illuminators as transmitters due to its ability of"four counteraction". By studying conventional radar imaging theory and imaging methods and considering the specialities of the passive radar system based on opportunity illuminators, this paper firstly deduces that the relationship between the target scattering function and the echo signal holds to be a Fourier transform pair by analyzing the texture of echo signal in passive radar imaging system; then presents a passive radar imaging algorithm which makes use of multiple receivers to form a synthetic aperture for imaging in the case of single external illuminator available. Because collected data is non-uniform and sparse in Fourier space, interpolation can not be applied to radar imaging. We derive and present an imaging algorithm which processes data in polar grid. As a result of removing the data error caused by interpolation, the proposed algorithm makes full use of original precise data and thus improves the quality of the final image. The factors that influence the image quality are discussed at the end of this dissertation.