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ISAR imaging of manoeuvring targets with the range instantaneous chirp rate technique 总被引:1,自引:0,他引:1
Zhao-Zhao G. Ya-Chao L. Meng-Dao X. Genyuan W. Shou-Hong Z. Zheng B. 《Radar, Sonar & Navigation, IET》2009,3(5):449-460
The conventional range instantaneous Doppler (RID) algorithm is a well accepted inverse synthetic aperture radar (ISAR) imaging method for manoeuvring targets. In the RID imaging, the cross-range resolution depends on the instantaneous Doppler of scatterers at the imaging instant. For a high manoeuvring target, the instantaneous Doppler of scatterers may be small at some imaging instants and the satisfactory RID images may not be obtained. On the other hand, a large instantaneous chirp rate is often present for the same scatterer at the same instant for RID imaging. In order to obtain some additional information of a manoeuvring target, a novel ISAR imaging approach, referred to as the range instantaneous chirp (RIC), is proposed based on instantaneous chirp rate of scatterer to provide cross-range resolution. Using the proposed imaging algorithm, with the same received data of RID, a RIC image is generated at the same instant with a different `view`. Therefore the RIC image may provide some additional information that is not shown in the RID image. With both the RIC and RID images, a better target recognition and identification can be achieved for high-manoeuvring targets. The proposed RIC algorithm is verified by raw radar data. 相似文献
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受环境因素与人类活动的影响,塔里木河中游地区近年植被长势及分布变化较大,通过对植被的动态监测分析,可为塔里木河生态保育对策的制定及植被保护研究提供科学依据.本文采用面向对象的Geodatabase模型,使用地理信息系统(GIS)对空间、属性数据的管理分析功能,以塔里木河中游为研究区,选取通过遥感图像处理平台ENVI计算得到的2000、2006、2010、2015年四期归一化植被指数(NDVI)为研究数据,通过使用ArcGIS对NDVI进行空间分布特征研究,设计出一种塔里木河中游植被指数空间数据库,以实现空间、属性数据的存储管理一体化.该植被指数空间数据库能直观的反映出研究区植被变化及生长情况. 相似文献
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针对全连接前馈神经网络不能有效应对时变系统的问题, 提出一种动态自适应模块化神经网络结构. 该网络采用减法聚类算法在线辨识工况数据的空间分布, 利用RBF 神经元实现对数据样本空间的划分, 并结合模糊策略将不同子样本空间的数据动态分配给不同的子网络, 最后对各子网络的输出进行集成. 该模块化网络中子网络数量和子网络规模都能根据所学时变任务动态自适应调整. 通过对不同时变系统的预测表明了该网络能够有效跟踪时变系统. 相似文献
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