基于SDR的探测雷达反演树干分层介电参数仿真  

Inversing the dielectric parameters of trunk layers by SDR-baseddetection radar

作　　者：周海洋 马和龙 夏鹏凯 孙卿峰 林剑辉[1,2,3] ZHOU Haiyang;MA Helong;XIA Pengkai;SUN Qingfeng;LIN Jianhui(School of Technology,Beijing Forestry University,Beijing 100083,China;Key Laboratory of National Forestry and Grassland Administration on Forestry Equipment and Automation,Beijing 100083,China;State Key Laboratory of Efficient Production of Forest Resources,Beijing 100083,China)

机构地区：[1]北京林业大学工学院,北京100083 [2]林业装备与自动化国家林业和草原局重点实验室,北京100083 [3]林木资源高效生产全国重点实验室,北京100083

出　　处：《农业工程学报》2024年第20期165-173,共9页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金项目(31901238)。

摘　　要：为有效检测树干分层介质厚度和相对介电常数,该研究提出一种基于雷达探测的树干分层结构介电参数反演方法。基于斯涅耳定律结合树干生理结构特点,构建雷达信号在树干分层结构中的传播模型。利用软件定义无线电平台(software defined radio,SDR)搭建树干探测雷达。然后采用稀疏分解算法、K-SVD字典训练以及层剥离算法对探测雷达回波信号进行参数反演,并对不同的稀疏分解算法反演结果进行了对比。试验表明在回波混叠和无混叠的情况下,该方法均能够对树干分层介质厚度和相对介电常数进行估算;无混叠时相对介电常数和厚度的反演误差分别在2.93%和3.5%以内,混叠时相对介电常数和厚度的反演误差分别在7.52%和7.61%以内。综合试验结果表明,在5种反演算法中,SAMP算法在未知信号稀疏度的条件下表现最佳,具有较高的反演准确率和鲁棒性。Tree trunks with thick bark can be expected to serve as the potential water storage capacity.Moisture content is one of the most important indicators to monitor the physiological condition of tree trunks in the development of agriculture and forestry.Therefore,it is crucial to accurately obtain the thickness and relative dielectric constant of the layered medium in tree trunks.The growth and health status of trees can be evaluated to optimize the water management strategies.To this end,this study aims to invert the dielectric parameters of tree trunk layered structure using radar detection.Non-invasive detection was realized for the internal structure of tree trunk.The electrical characteristics of different layers were obtained for the medium layers in the tree trunk.According to Snell's law,the physiological structure of tree trunks were combined to construct the propagation model of radar signals in the layered structure of tree trunks.Electromagnetic properties of different media layers in tree trunks were considered,such as the thickness and relative dielectric constant differences of bark,sapwood,and heartwood.These key parameters were then evaluated using radar echo signals.In addition,the accurate inversion was also performed on the dielectric parameters of tree trunks using sparse decomposition.K-SVD dictionary training was combined to process and analyze radar signals.A software defined radio(SDR)platform was used to build a tree trunk detection radar system in the experiment.The accuracy of detection was further improved to easily adjust the operating frequency of the radar,and then modify the signal processing under different environments.Layer stripping algorithm was selected to invert the dielectric constant and thickness of the layered structure in the tree trunks.The echo signals detected by radar were collected to evaluate the performance of the improved model.A comparative experiments were conducted on the radar detection under two conditions:aliasing and no aliasing in the echo signal.In the ab

关 键 词：雷达 反演 树干检测 软件无线电(SDR) 分层结构 介电参数 

分 类 号：S126[农业科学—农业基础科学]