一种相控阵雷达波束指向误差的外场高精度标定方法

A Field High Accuracy Calibration Method of Phased Array Radar Beam Pointing Deviation

相控阵雷达通过电扫描调整波束指向,并通过测量目标回波与预期波束指向的偏差完成目标角度测量。当实际波束指向偏离预期时,将导致目标角度解算存在误差,随着对雷达测角精度要求的提升,波束指向误差对雷达测角性能的影响将成为关键因素。波束指向误差通常可以在微波暗室内对阵面完成标定和补偿,然而,现代大型相控阵因规模庞大而使得在暗室内进行波束指向标定变得困难,甚至缺乏可行性。文中针对基于惯导实现阵面姿态测量的相控阵雷达,提出了一种雷达波束指向误差的外场高精度标定方法。首先,分析了相控阵雷达波束指向误差产生的主要原因与惯导安装误差、电轴机械轴指向误差、波控码计算误差等因素相关;然后,建立了误差传递模型,并基于最小二乘估计原理,给出了一种通过雷达跟踪标校体的测量误差数据解算波束指向误差并予以补偿的标定方法;最后,完成了外场实装试验验证。试验结果表明,基于所提方法进行外场标定可大幅降低波束指向误差,对大型相控阵雷达高精度角度测量的工程实现有较大的参考价值。

Phased array radar adjusts the beam direction by electrical scanning,and completes the target angle measurement by measuring the deviation between the target echo and the expected beam pointing.When the actual beam pointing deviates from the expected,there will be errors in the target angle calculation.With the increasing demand for radar angle measurement accuracy,the influence of beam pointing deviation on radar angle measurement performance will become a key factor.Beam pointing deviation can usually be calibrated and compensated in the microwave anechoic chamber.However,modern large-scale phased arrays make beam pointing calibration difficult and even impractical in anechoic chambers due to their large scale.In this paper,a field high accuracy calibration method of radar beam pointing deviation is proposed for phased array radar based on inertial navigation to achieve array attitude measurement.First,the main reasons for the beam pointing deviation of phased array radar are analyzed,which are related to inertial navigation installation error,electrical axis and mechanical axis pointing deviation,and beam control code calculation error.Then,an error propagation model is established.A calibration method is presented to solve the beam pointing deviation and compensate it by measuring error data of radar tracking calibration.Finally,the field experiment verification is completed.The experimental results show that the beam pointing deviation can be greatly reduced by using the proposed method for field calibration,which has great reference value for the engineering implementation of high accuracy angle measurement for large scale phased array radar.