Channel-level STAP And ATBF Research For Wideband Phased-array Radar

Sea clutter suppression and the naval ship target detection is the key problem what is the anti-ship missile guidance radar facing,Space Time Adaptive Processing(STAP),Adaptive Beam Forming(ABF)and high resolution imaging is important to suppress clutter and improve the guidance radar detection performance.For the phased array wideband imaging radar system and target detection in strong clutter background,studying the theory method and the technical implementation ways of space-time adaptive processing,adaptive beam-forming,clutter suppression,target detection and angle measurement has important academic and practical application value.In this paper,aiming at phased array wideband mono-pulse radar system and the ship target detection of a certain height characteristics of static or movement on the sea surface,because the existing channel-level STAP method is difficult to achieve the compatibility issues of clutter suppression and elevation angle measurement,this paper systematically studied the method of clutter suppression,target angle measurement based on the combination of channel-level STAP and adaptive transmitting beam forming(ATBF),realized the channel-level clutter suppression which is fully compatible with single pulse angle measuring system,then studied the influence of channel-level STAP and ATBF method when arrays or the sub-arrays are damaged,and puts forward the correction method of single pulse multi-channel angle measuring.In this paper,the main work and innovation points are as follows.(1)In phased array radar antenna pattern function analysis and simulation,increased the influence of the direction figure function and mono-pulse ratio function when meeting the damage of antenna arrays or sub-arrays,the corresponding conclusion,namely,for the phased array radar,when there was a partial damage in antenna arrays or sub-arrays,pattern function on the modified elevation and azimuth direction does not meet the separable feature,mono-pulse ratio function in the radar beam within the scope of main lobe is no longer a linear function,it provides theory basis for the subsequent target angle measurement method.(2)The existing channel-level STAP method was analyzed,because the existing method has a defect which is difficult to improve elevation angle measurement precision,this paper puts forward the channel-level STAP combining with ATBF for clutter suppression and the target angle measurement,the method is using conventional transmitting pattern and the modified transmitting pattern alternatively,the first compound frame takes the conventional transmitting pattern to form a beam,and takes channel-level STAP to complete clutter cancellation,target detection and obtain the equivalent receiving pattern which is null-formed at the direction of clutter to be suppressed,in the second compound frame,the receiving pattern is conversed to the modified transmitting pattern according to the transceiver reciprocity principle and form the transmitting beam,target angles are measured according to the conventional mono-pulse mode.At the same time,theoretical analysis,deduction and computer simulation show that the method improved the measurement precision of the elevation angle and the azimuth angle,verified the correctness,effectiveness and the superiority of the method.(3)This paper analyzed the influence of clutter suppression and target angle measurement in local damage of the phased array radar antenna arrays or the sub-arrays,the corresponding conclusion,namely,is that the proposed channel-level STAP and ATBF method is basically not influenced in the process of clutter suppression.But as the sum and difference channel pattern function will be not in the separation of the modified azimuth direction and elevation direction,and the sum and difference channel pattern function will have phase difference,the original single pulse angle measuring method based on linear ratio function will be in failure.Therefore,in this paper,aiming at the condition of the damage is known,combined with its real-time requirements of missile-borne application,established the angle measurement equation in the damage cases based on the modified sum and difference channel pattern function,the joint measurement method based on the limited number of iteration is proposed to calculate the target azimuth and elevation angle,this paper carried on detailed theoretical analysis,deduction and computer simulation,and verify the effectiveness and the correctness of the proposed method.