基于粒子群算法的相控阵海浪波谱仪天线增益校正方法

Antenna Gain Calibration Method for Phased Array Wave Spectrometer Based on Particle Swarm Algorithm

相控阵海浪波谱仪是一个Ku波段真实孔径雷达,通过在小入射角下照射海面,接收海面回波功率,并去除雷达EIRP(Effective Isotropically Radiated Power,等效全向辐射功率)、天线方向图、系统损耗等雷达自身的影响因子,获取海面三维信息。这些影响因子可以在微波暗室中测量,其中EIRP、系统损耗可认为是常数量,但是,天线方向图是与入射角、方位角相关的三维变量,测量受到暗室系统精度的限制,并且,相控阵海浪波谱仪最小处理单元是雷达照亮的圆环形条带,照射的过程即是对该环形条带中的变量进行二维积分,成为一个随入射角变化的后向散射系数剖线,因此,天线方向图的微小误差,都会对海面后向散射系数剖线形状产生显著影响,出现“凹现象”问题。针对该问题,本文基于粒子群算法进行了积分天线增益的校正工作,利用机载飞行试验数据进行了算法验证,通过与同步观测浮标海浪测量结果比对,表明本算法可有效改善“凹现象”,使回波数据有效率提升了12%,为业务化的波浪谱生产提供了技术支撑。

The phased array wave spectrometer is a Ku-band real aperture radar that illuminates the sea surface at small inci-dence angles to receive sea surface echo power.It extracts three-dimensional sea surface information by removing radar-related fac-tors like EIRP(Effective Isotropically Radiated Power),antenna patterns,and system loss,which can be measured in a microwave anechoic chamber.However,the antenna pattern's precision is limited,leading to the'concave'anomaly in the backscatter coefficient profile that hinders wave spectrum inversion.To address this,the paper uses particle swarm optimization to correct integral antenna gain.Validation with flight test data shows a 12%improvement in data reliability,supporting operational wave spectrum production.