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干扰时序控制模块中射频滤波器的改进
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作者 刘禹 《舰船电子对抗》 2013年第2期110-112,117,共4页
在干扰时序控制模块中,射频滤波器是最重要的滤波器。在分析原上下限射频滤波器的基础上,提出了一种新的基于双口随机存储器的射频滤波器作为改进方法,并对两者的性能进行了比较。仿真和分析证明了改进方法取得了性能的提高,值得工程应用。
关键词 干扰时序 控制模块 射频滤波器
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激光导引头时序抗干扰技术分析及实验 被引量:13
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作者 邢晖 雷萍 马娜 《红外与激光工程》 EI CSCD 北大核心 2012年第2期461-465,共5页
为提高激光导引头抗主动式干扰的能力,在时序上通常采用时间波门精确控制技术、波门内首/末脉冲锁定技术和脉冲时序相关技术等手段。在分析激光导引头的时序抗干扰技术的基础上,针对国内外现役激光导引头所采用的时序抗干扰措施进行了... 为提高激光导引头抗主动式干扰的能力,在时序上通常采用时间波门精确控制技术、波门内首/末脉冲锁定技术和脉冲时序相关技术等手段。在分析激光导引头的时序抗干扰技术的基础上,针对国内外现役激光导引头所采用的时序抗干扰措施进行了实验设计,对风标式、动力陀螺式、框架式3类激光导引头的抗干扰技术进行了理论分析和实验研究。结果表明:根据激光导引头的受干扰的情况,可实现对采用的时序干扰措施进行较为准确的预测,并据此提出了一种更为有效的激光有源欺骗干扰方法。 展开更多
关键词 激光导引头 时序干扰技术 波门 激光有源欺骗干扰
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消除蓝牙与WLAN系统共存干扰技术的研究与分析 被引量:1
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作者 彭菊红 胡丽莉 《计算机工程与应用》 CSCD 北大核心 2005年第22期150-152,共3页
蓝牙和WLAN系统共享2.4GISM频率,如何避免两者之间的干扰是无线通信技术面临的重要挑战。该文研究分析了消除蓝牙和WLAN系统共存间干扰的算法:蓝牙干扰避免时序(BIAS)算法和速率缩放算法。通过仿真,得到了蓝牙和WLAN系统共存的TCP性能... 蓝牙和WLAN系统共享2.4GISM频率,如何避免两者之间的干扰是无线通信技术面临的重要挑战。该文研究分析了消除蓝牙和WLAN系统共存间干扰的算法:蓝牙干扰避免时序(BIAS)算法和速率缩放算法。通过仿真,得到了蓝牙和WLAN系统共存的TCP性能。仿真结果表明这两种技术提高了蓝牙和WLAN系统共存的TCP性能,并且对消除共存系统间干扰也有明显效果。 展开更多
关键词 蓝牙 WLAN 干扰 蓝牙干扰避免时序 速率缩放
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雷达目标回波模拟器与雷达欺骗干扰机之间的异同对比 被引量:1
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作者 石荣 张礼 《火控雷达技术》 2020年第2期101-105,110,共6页
雷达目标回波模拟器与雷达欺骗干扰机都能够在雷达终端显示器上产生相似的预设虚假目标的点迹、航迹、甚至是图像,针对二者能否互换使用的问题,在对二者的结构组成、工作原理与主要功能简要介绍的基础上,从多个方面对二者之间的差异进... 雷达目标回波模拟器与雷达欺骗干扰机都能够在雷达终端显示器上产生相似的预设虚假目标的点迹、航迹、甚至是图像,针对二者能否互换使用的问题,在对二者的结构组成、工作原理与主要功能简要介绍的基础上,从多个方面对二者之间的差异进行了对比分析,同时总结了二者的共同之处与可相互借鉴之内容。从而为雷达目标回波模拟器与雷达欺骗干扰机的融合发展提供了重要参考。 展开更多
关键词 雷达回波模拟器 雷达目标回波模拟器 雷达干扰 雷达欺骗干扰 直接数字频率合成器 数字射频存储器 侦察引导 干扰时序控制
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Spatio-temporal Variations in Plantation Forests'Disturbance and Recovery of Northern Guangdong Province Using Yearly Landsat Time Series Observations(1986-2015) 被引量:4
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作者 SHEN Wenjuan LI Mingshi WEI Anshi 《Chinese Geographical Science》 SCIE CSCD 2017年第4期600-613,共14页
Forest disturbance plays a vital role in modulating carbon storage,biodiversity and climate change.Yearly Landsat imagery from 1986 to 2015 of a typical plantation region in the northern Guangdong province of southern... Forest disturbance plays a vital role in modulating carbon storage,biodiversity and climate change.Yearly Landsat imagery from 1986 to 2015 of a typical plantation region in the northern Guangdong province of southern China was used as a case study.A Landsat time series stack(LTSS) was fed to the vegetation change tracker model(VCT) to map long-term changes in plantation forests' disturbance and recovery,followed by an intensive validation and a continuous 27-yr change analysis on disturbance locations,magnitudes and rates of plantations' disturbance and recovery.And the validation results of the disturbance year maps derived from five randomly identified sample plots with 25 km^2 located at the four corners and the center of the scene showed the majority of the spatial agreement measures ranged from 60% to 83%.A confusion matrix summary of the accuracy measures for all four validation sites in Fogang County showed that the disturbance year maps had an overall accuracy estimate of 71.70%.Forest disturbance rates' change trend was characterized by a decline first,followed by an increase,then giving way to a decline again.An undulated and gentle decreasing trend of disturbance rates from the highest value of 3.95% to the lowest value of 0.76% occurred between 1988 and 2001,disturbance rate of 4.51% in 1994 was a notable anomaly,while after 2001 there was a sharp ascending change,forest disturbance rate spiked in 2007(5.84%).After that,there was a significant decreasing trend up to the lowest value of 1.96% in 2011 and a slight ascending trend from 2011 to 2015(2.59%).Two obvious spikes in post-disturbance recovery rates occurred in 1995(0.26%) and 2008(0.41%).Overall,forest recovery rates were lower than forest disturbance rates.Moreover,forest disturbance and recovery detection based on VCT and the Landsat-based detections of trends in disturbance and recovery(LandT rendr) algorithms in Fogang County have been conducted,with LandT rendr finding mostly much more disturbance than VCT.Overall,disturbances and recoveries in northern Guangdong were triggered mostly by timber needs,policies and decisions of the local governments.This study highlights that a better understanding about plantations' changes would provide a critical foundation for local forest management decisions in the southern China. 展开更多
关键词 plantation Landsat dense time series remote sensing forest disturbance and recovery driving forces northern Guangdong
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Application and comparison of coaxial correlation diagram and hydrological model for reconstructing flood series under human disturbance 被引量:3
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作者 HUANG Peng-nian LI Zhi-jia +2 位作者 LI Qiao-ling ZHANG Ke ZHANG Han-chen 《Journal of Mountain Science》 SCIE CSCD 2016年第7期1245-1264,共20页
Intense human activities have greatly changed the flood generation conditions in most areas of the world, and have destroyed the consistency in the annual flood peak and volume series. For design flood estimation, coa... Intense human activities have greatly changed the flood generation conditions in most areas of the world, and have destroyed the consistency in the annual flood peak and volume series. For design flood estimation, coaxial correlation diagram and conceptual hydrological model are two frequently used tools to adjust and reconstruct the flood series under human disturbance. This study took a typical mountain catchment of the Haihe River Basin as an example to investigate the effects of human activities on flood regime and to compare and assess the two adjustment methods. The main purpose is to construct a conceptual hydrological model which can incorporate the effects of human activities. The results show that the coaxial correlation diagram is simple and widely-used, but can only adjust the time series of total flood volumes. Therefore, it is only applicable under certain conditions(e.g. There is a strong link between the flood peaks and volumes and the link is not significantly affected by human activities). The conceptual model is a powerful tool to adjust the time series of both flood peak flows and flood volumes over different durations provided that it is closely related to the catchment hydrological characteristics, specifically accounting for the effects of human activities, and incorporating expert knowledge when estimating or calibrating parameters. It is suggested that the two methods should be used together to cross check each other. 展开更多
关键词 Flood regime change Human activities Coaxial correlation diagram Conceptual hydrological model Mountain catchment Flood peak flows
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