匹配与姿态估计的粒子群优化算法

点模式匹配问题是机器视觉与模式识别领域中一个基础问题,在目标识别、医学图像配准、遥感图像匹配、姿态估计等方面都得到广泛应用。提出一种在仿射变换下利用粒子群优化算法进行图像点模式下的匹配与姿态估计的方法。算法首先把点集匹配问题转化为解空间为仿射参数空间下的目标函数优化问题,然后运用粒子群算法对相应的变换参数进行搜索,获得问题最优解。本文贡献如下：1)给出一种仿射参数的初始估计方法,提高了后续算法搜索效率;2)引入阈值和次近点规则,改进了最近点匹配搜索方法,能较好地拒绝出格点（outliers）,并提高算法有效性;3)从两方面对PSO方法进行了改进,加强了原PSO的全局和局部搜索能力。实验结果表明,算法具有有效性和鲁棒性。     

非线性目标谐波散射特性建模研究

非线性目标的入射功率-散射谐波功率曲线（后文简称为谐波散射特性）对增强非线性探测系统的鲁棒性和后续的目标分类识别具有重大意义.本文研究了非线性目标谐波散射特性的建模方法和对应的参数求解方法.文章通过建立等效电路,导出了非线性伏安特性曲线与散射参数的关系模型,并提出一种基于优化的递进求精解法来提高模型参数的求解效率;以齐纳二极管的实测基波数据作为建模求解的测试示例,结果表明建模参数的仿真谐波曲线与测量的谐波曲线在测量功率段均符合较好.故本文建模方法可为后续更多非线性目标（如PIN管、三极管等）谐波散射特性的获取提供有益指导.     

基于软件无线电的雷达嵌入式通信验证系统

雷达嵌入式通信（Radar-Embedded Communication,REC）是一种在雷达后向散射回波中嵌入通信信号的新型隐蔽通信手段。相较于传统的隐蔽通信方式,REC具有其独特的优势,在军事和民用领域都有着非常广阔的应用前景。本文基于通用软件无线电外设（Universal Software Radio Peripheral,USRP）硬件平台和实验室虚拟仪器工作平台（Laboratory Virtual Instrumentation Engineering Workbench,LabVIEW）开发了一套REC验证系统,并对系统的可靠性能和抗截获进行了测试分析,初步验证了REC的可行性。测试结果表明,相对于仿真结果,本系统具有一定的性能损失,但在可控范围内,且本系统更加贴近于真实场景,可以用作REC技术的试验平台,为REC从理论走向现实奠定基础。      

Design and implementation of the optical fiber control and transmission module in multi-channel broadband digital receiver

An optical fiber control and transmission module is designed and realized based on Virtex-7 field programmable gata array （FPGA）, which can be applied in multi-channel broadband digital receivers. The module consists of sampling data transfer submodule and multi-channel synchronous sampling control submodule. The sampling data transmission in 4× fiber link channel is realized with the self-defined transfer protocol. The measured maximum data rate is 4.97 Gbyte/s. By connecting coherent clocks to the transmitter and receiver endpoints and using the self-defined transfer protocol, multi-channel sampling control signals transferred in optical fibers can be received synchronously by each analog-to-digital converter （ADC） with high accuracy and strong anti-interference ability. The module designed in this paper has certain reference value in increasing the transmission bandwidth and the synchronous sampling accuracy of multi-channel broadband digital receivers.