基于全极化的相参雷达迁飞昆虫观测

昆虫雷达是迁飞昆虫监测的重要工具。传统昆虫雷达是非相参体制，距离分辨率低，采用旋转极化方式，测量效率低。本文介绍了一种基于全极化的相参雷达系统，该系统工作在Ku频段，采用同时全极化体制，可同时测量目标HH、HV、VH、VV极化回波，采用调频步进频波形，合成信号带宽800MHz，距离分辨率高达0.2m。雷达采用单目标校准技术，利用金属球和倾斜的金属丝作为定标体进行极化校准；采用基于散射矩阵的昆虫朝向提取方法，从昆虫主特征值向量中提取朝向；采用基于相位调制的振翅频率提取方法，通过对目标振翅回波的相位进行傅里叶分析提取昆虫振翅频率。通过外场实验，验证了雷达极化校准的有效性以及测量昆虫朝向和振翅频率的能力。 

Fully Polarimetric Coherent Radar for Migratory Insect Observation

The entomological radar is an important tool for migration insect observation. The traditional entomological radars are rotation polarization non-coherent radars with low range resolution. This paper introduced a fully polarimetric coherent radar that worked at Ku-band and employed the instantaneous full polarization that was able to instantaneously measure the HH, HV, VH and VV polarization signal of the target. It employed the frequency modulation step frequency waveform configuration, and its synthetic bandwidth was 800MHz. The range resolution of the radar was 0.2m. Based on the single target calibration technique, the radar measured the SM of a metal ball and a tilt metal line for radar polarization calibration. The insect orientation can be extracted from the main eigenvector of the SM based on the scattering matrix (SM)-based insect orientation estimation method. The phase modulation-based insect wing-beat frequency extraction method was applied for wing-beat frequency measurement. The field experiments were conducted, which validated the effectiveness of the polarization calibration and the orientation and wing-beat frequency measurement abilities of the radar.