Radar Signal Processing Technology Based On Distributed Array

Since the inception of the first radar systems in 1930 s,radar technologies have been developed rapidly in many military fields.Especially in recent years,in order to seek more powerful weapons performance,for many kinds of aircraft,people hopes that radar antennas elements they carried can be installed on the surface of the air vehicles and be formed into conformal arrays antennas.For the sake of possibly extending the physical aperture of arrays,we arranged conformal antennas in a distributed manner and introduced the conception of distributed conformal arrays.Placing distributed conformal arrays antennas on the aerobat surface is the use of geometric shapes,designing low price,big aperture's directional antennas arrays.The principal contents of this thesis are divided into four parts.Firstly,introduced the model of arbitrary arrays and derived the pattern function of arbitrary arrays.And then,used the basic conformal array—uniform circular array as an example,pattern synthesis has been carried on.Once more,used directional elements to reducing the sidelobe level;the influence of the radius and the number of elements participated in digital beam forming(DBF)on uniform circular array pattern are also analyzed;used the amplitude-only,the phase-only and the phase-amplitude pattern synthesis methods which are based on classical genetic algorithm to optimize sidelobe level.Secondly,established the model of sparse circular array.Once more,optimized the elements arrangement of circular array composed of directional elements and circular array composed of omnidirectional elements by using a sparse array method based on modified genetic algorithm,a sparse array method based on modified differential evolution algorithm and a sparse array method based on combination of two modified algorithms.Thirdly,derived the pattern function of cylindrical arrays.And then,the influence of the radius,the number of elements participated in digital beam forming(DBF)and the number of circular arrays contained in a cylindrical array on cylindrical array pattern are also analyzed.Finally,established the model of sparse perpendicular dimension of a cylindrical array.Optimized the vertical dimension elements arrangement of cylindrical array based on classical genetic algorithm.The influence of the channel gain and phase errors on cylindrical array pattern is also discussed.Elaborated signal processing of radar combining with a radar system raised by ourselves which is used for detecting low altitude and small targets.