共查询到20条相似文献,搜索用时 46 毫秒
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采用空间稀疏性的单星无源定位方法 总被引:1,自引:0,他引:1
针对传统单星定位中,参数估计和目标定位被分为两个独立阶段造成定位不优化的问题,提出了一种采用空间稀疏性的单星无源定位方法.该方法通过持续测量目标信号的多普勒频率,利用干扰源位置在地面分布的空间稀疏性,通过构建干扰信号的多普勒频率与地理位置满足的凸优化问题来实现干扰源定位.该定位方法利用了干扰信号的累积时间和干扰源位置的空间分布信息,在一个阶段中完成卫星定位.仿真证实该方法在单星定位中可得到较高的定位精度. 相似文献
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随着通信设备功能的多样化,要求通信干扰系统必须产生多种形式的干扰信号,针对采用传统方法时每种干扰信号均需要一种独立硬件电路,从而造成干扰系统复杂、工程难以实现的问题,提出了基于FPGA实现通用通信干扰信号发生器的方法,详细论述了系统方案设计,并重点阐述了正交调制和DDS两项关键技术.对该系统进行了硬件实现,给出了产生多种不同形式干扰信号时的实验结果,证实了系统的通用性,且该系统能够通过更新干扰模块的软件来适应不断发展的通信体制,具有相当大的灵活性和开放性. 相似文献
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本文把雷达目标回波信号和欺骗干扰信号纳入到统一框架下进行分析,提取了基于原子分解理论的特征及时延和频偏匹配度特征。最后利用支持向量机(Support Vector Machine,SVM)分类器,对雷达接收信号进行了分类识别。仿真结果验证了该方法不仅可以有效检测欺骗干扰信号的存在,还可以识别欺骗干扰信号的类型。 相似文献
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By means of exact conformal mapping method we have defined character of dependence of squares amounts of angular part of film
element on angled part dimension. We propose relations, approximating obtained dependence. Calculation results and experimental
researches of large-scale models are represented. 相似文献
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Moshrefzadeh R.S. Radcliffe M.D. Lee T.C. Mohapatra S.K. 《Lightwave Technology, Journal of》1992,10(4):420-425
The temperature dependence of refractive index of polymer films was determined for a number of slab waveguides by a grating coupling method. This dependence was examined as a function of parameters such as molecular weight and glass transition temperature of the polymer. Temperature-induced changes in N TE-N TM , N being the effective index, were studied systematically for different slab waveguide compositions. It is shown that with proper device design and choice of polymeric materials, thermal effects can be reduced 相似文献
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The article describes a model representation of radar probing data in form of a mixture of background and target samples, which is the sum of two random variables with very different parameters. For model development we research the behavior of the central moments of the distribution mix without assuming the distribution law form. An example it is described the detection of the signal at the output of compression system of chirp ionosonde. 相似文献
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解决IP网QoS问题是目前通信领域的研究热点之一.虽然研究已经取得了一定的进展,但人们对于IP 网QoS本身的含义及相关的问题还有着不同的理解.本文将从IP网QoS的定义入手讨论相关的一些问题以及解决IP网QoS问题所做的各种努力. 相似文献
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《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1968,56(6):1024-1032
Assuming that visual responses are due to the action of particles on the membrane of the visual cells, the stochastic variability of the response should be a function of the number of particles producing it. Quantitative predictions can be made with the aid of a model proposed in previous articles. It is found that responses produced in visual cells of Limulus by absorption of a single photon have the stochastic properties which would be expected if the response to one photon were brought about by 25 particles. It is concluded from this that the processes leading to visual responses produce multiplication of particles. The effects of temperature and of metabolic poisons suggest that these processes are of chemical nature. 相似文献
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The approaches to prepare a uniform and unified scientific terminology of chemical carcinogenesis are presented. The main definitions proposed (carcinogen, initiation, promotion, mutagen, multistage carcinogenesis, anti-carcinogen, cocarcinogen, carcinogenic risk, etc.) are based on the current state of comprehending mechanisms of the action of chemical carcinogens. 相似文献
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近红外光谱技术在水果品质无损检测中应用的研究与现状 总被引:6,自引:0,他引:6
简单概述了我国水果产业的发展现状,着重阐述了国内外利用近红外光谱技术进行水果品质无损检测的最新研究进展,分析了当今研究中存在的问题,并对利用近红外光谱技术进行水果检测的前景进行了展望,提出了一些建议。 相似文献