摘要
精确的昆虫体型参数反演对于昆虫种类辨识具有重要意义。当前三种精度最高的单频段反演方法包括“特征值法”、“联合使用极化方向图(即不同线极化方向的雷达散射截面积(Radar Cross Section,RCS))形状参数和极化平均RCS法”、“行列式法”,前两种方法须判断昆虫极化方向图最大值方向与体轴方向的平行/垂直关系(即昆虫类型),昆虫类型判断错误会导致反演误差增大,“行列式法”无须判断昆虫类型但精度差。为克服现有方法不足,实现高精度昆虫体型参数反演,分析了X波段(9.5 GHz)昆虫腹部面极化方向图特性,发现昆虫腹部极化方向图最小值(简称最小极化RCS)与昆虫体长和体重均存在良好映射关系,可作为特征实现昆虫体型参数反演。为推导最小极化RCS的解析表达,首先基于对称昆虫模型推导了极化方向图形状与散射矩阵特征值的关系,并在此基础上推导了最小极化RCS的计算方法,给出了基于最小极化RCS反演昆虫体长和体重的经验公式。将所提方法命名为“最小RCS法”。与前述三种方法对比发现,对于体长反演,“最小RCS法”精度最高,而对于体重反演,“最小RCS法”精度略差于“特征值法”与“联合使用极化方向图形状参数和极化平均RCS法”。通过仿真分析了极化误差对于四种方法反演精度的影响,结果表明,两种须判断昆虫类型的方法受极化相位误差影响非常严重,而“最小RCS”法抗极化误差性能好,几乎不受相位误差的影响。
Accurate estimation of insect morphological parameters is of great significance for insect species identification.At present,the three single-band estimation methods with the highest accuracy include“eigenvalue method”,“the method combined the shape parameter of polarization pattern(i.e.,Radar Cross Section(RCS)of different linear polarization di⁃rections)and mean polarization RCS”,and“determinant method”.The first two methods need to judge the parallel/verti⁃cal relationship between the maximum direction of the insect polarization pattern and the direction of the body axis(i.e.insect type).The error of insect type judgment will lead to the increase of estimation error.The“determinant method”does not need to judge the insect type but has poor accuracy.In order to overcome the shortcomings of existing methods and achieve accurate estimation of insect morphological parameters by entomological radar,the characteristics of X-band(9.5 GHz)insect abdominal polarization pattern(i.e.,Radar Cross Section(RCS)of different linear polarization direc⁃tions)were analyzed.It was found that the minimum value of abdominal polarization pattern(minimum polarization RCS for short)had a good mapping relationship with the body length and body mass of insects,which could be used as a feature to realize the estimation of insect morphological parameters.In order to derive the analytical expression of the minimum po⁃larization RCS,the relationship between the shape of the polarization pattern and the eigenvalue of the scattering matrix was firstly derived based on the symmetric insect model,and then the calculation method of the minimum polarization RCS was derived,and the empirical formula of the estimation of insect body length and body mass based on the minimum polar⁃ization RCS was given.The proposed method is named“minimum RCS method”.Compared with the above three meth⁃ods,it was found that for body length estimation,“the minimum RCS method”had the highest accuracy,while the mini⁃mum RCS method has a slightly lower accuracy than“eigenvalue method”and“the method combined the shape parameter of polarization pattern and mean polarization RCS”.The effects of polarization errors on the estimation accuracy of the four methods are analyzed by simulation.The results show that the two methods that need to determine the type of insects are seriously affected by the polarization phase errors,while“the minimum RCS method”has good anti-polarization error per⁃formance and is almost unaffected by the phase errors.
作者
王江涛
王锐
李卫东
李沐阳
李云龙
钱李昌
胡程
WANG Jiangtao;WANG Rui;LI Weidong;LI Muyang;LI Yunlong;QIAN Lichang;HU Cheng(Radar Research Lab,School of Information and Electronics,Beijing Institute of Technology,Beijing 100081,China;Advanced Technology Research Institute,Beijing Institute of Technology,Jinan,Shandong 250300,China;Key Laboratory of Electronic and Information Technology in Satellite Navigation(Beijing Institute of Technology),Ministry of Education,Beijing 100081,China;Troop 31511,People’s Liberation Army,Beijing 100037,China)
出处
《信号处理》
CSCD
北大核心
2023年第9期1651-1663,共13页
Journal of Signal Processing
基金
国家自然科学基金(62001021,62201049)
中国博士后科学基金(2022M720445)
山东省重点研发计划(重大科技创新工程)项目(2020CXGC010802)
山东省自然科学基金(ZR2022QF073)。
关键词
昆虫雷达
体型参数反演
极化方向图
最小极化RCS
entomological radar
morphological parameters estimation
polarization patterns
minimum polarization RCS
