基于LabVIEW的频谱仪控制系统设计

频谱仪是合成孔径雷达地面集成测试系统必需的测试仪器，本文提出用基于LabVIEW的虚拟仪器技术对频谱仪操作进行软件自动控制．引入LabVIEW的新增Event Structure事件驱动编程技术，提高对仪器的控制速度；运用LabVIEW的全局变量技术，实现控制参数的实时跟踪显示；运用LabVIEW的数据存储技术，实现测试原始数据文本文件和主控界面图像文件的保存．对以上技术应用的难点进行了详细介绍．经在中科院电子所某合成孔径雷达地面集成测试中的应用表明，该设计具有方便和实用的优点．     

基于自适应收缩因子的SAR图像去噪

针对合成孔径雷达 (SAR)图像固有的斑点噪声 ,提出了基于自适应收缩因子的去噪方法 .该方法首先将图像分解至平稳小波域 ,利用与信号相关小波系数的空间及尺度相关性 ,自适应地得到收缩因子 ,修正小波系数 .与基于Mallat分解的阈值去噪及Wiener滤波相比 ,该方法在有效抑制SAR图像噪声的同时 ,较好地保持了图像边缘细节 ,达到了理想的去噪效果     

基于多重分形分析的SAR图像消噪增强研究

根据SAR图像中原始信号与噪声的多重分形谱的不同，提出了一种基于奇异性分析的雷达图像消噪新方法。在图像经过多重分形分析后，通过对多重分形谱相关的Holder指数进行特征化处理来实现图像消噪。经过实验确定当变化后的Holder指数略大于1．7时，最终恢复的图像消噪效果最佳。这种方法可以在尽量保留信号奇异性(如边缘，纹理等)相关信息情况下，使得图像平滑，噪声消除。     

SAR成像中加权处理的改进研究

点目标回波信号经过匹配滤波后，输出压缩脉冲包络近似为辛格函数的形状，在主瓣两侧存在逐渐递减的旁瓣，抑制旁瓣是合成孔径雷达成像研究的重要内容，而加权技术是实现抑制旁瓣的重要途径。在分析传统加权技术的基础上，对其进行了改进，并用改进的加权方法对点目标回波信号及成像过程进行了计算机仿真；结果表明，该方法与传统加权技术相比，没有展宽主瓣宽度，且具有较好的旁瓣抑制能力。     

贝叶斯融合在SAR图像分类中的应用

本文研究将数据融合理论用于SAR图像分类.通过贝叶斯理论进行多通道SAR图像测量级数据融合,充分利用像素的从属信息并获得单通道分类无法获取的分类结果,有效保留各通道有用信息并抑制图像中的斑点噪声;针对贝叶斯融合涉及到的先验概率的问题采用两种方式进行先验概率估计,对估计引起的马赛克现象提出了三种解决方法;并提出三种先验概率融合方法,比较得出相对最优的SAR图像多通道分类方案.     

Large-scale mapping of boreal forest in SIBERIA using ERS tandem coherence and JERS backscatter data

Siberia's boreal forests represent an economically and ecologically precious resource, a significant part of which is not monitored on a regular basis. Synthetic aperture radars (SARs), with their sensitivity to forest biomass, offer mapping capabilities that could provide valuable up-to-date information, for example about fire damage or logging activity. The European Commission SIBERIA project had the aim of mapping an area of approximately 1 million km² in Siberia using SAR data from two satellite sources: the tandem mission of the European Remote Sensing Satellites ERS-1/2 and the Japanese Earth Resource Satellite JERS-1. Mosaics of ERS tandem interferometric coherence and JERS backscattering coefficient show the wealth of information contained in these data but they also show large differences in radar response between neighbouring images. To create one homogeneous forest map, adaptive methods which are able to account for brightness changes due to environmental effects were required. In this paper an adaptive empirical model to determine growing stock volume classes using the ERS tandem coherence and the JERS backscatter data is described. For growing stock volume classes up to 80 m³/ha, accuracies of over 80% are achieved for over a hundred ERS frames at a spatial resolution of 50 m.     

Monitoring of slow ground deformation by ERS radar interferometry on the Vauvert salt mine (France): Comparison with ground-based measurement

The differential SAR Interferometry (DInSAR) technique has been applied to a test site near Vauvert (France) to detect and monitor ground deformation. This site corresponds to the location of an industrial exploitation of underground salt using the solution mining technique. An area of subsidence has been observed using in situ measurements. Despite conditions unfavorable for InSAR because of the vegetal cover, we show that radar remote sensing observations provide valuable information which substantially improves our knowledge of the phenomenon. An adaptive phase filtering process has been used to improve the coherence level. In particular, our study shows that the geometry of the subsidence bowl is different to that previously assumed using ground-based techniques only. The size of the subsidence bowl (8 km) is larger than expected. This information will be useful for further modeling of the deformation and to improve the coverage of the in situ measurement networks. It also shows that radar interferometry can be used for the long-term monitoring of such sites and to predict potential environmental issues.     

基于RTLinux构建机载SAR实时成像处理器嵌入式控制系统

面向地学处理的机载SAR实时成像处理器由一组连接在工业总线上的数据处理板和一个嵌入式主控子系统构成，成像处理器的总体设计对主控系统的实时性，稳定性及可扩展性提出了严格的要求，比较了传统的嵌入式工业控制系统的设计方法，设计并实现一个基于廉价的PC与RTLinux的主控系统，分析了主控系统的两个重点；DSP宿主环境和RTLinux下的混合任务集，并通过给出一个RTLinux与Linux调度精度和误差的对比试验及其结果，证明了基于RTLinux的主控系统对支持细粒度调度方面的优越性。     

新SAR模拟测试信号产生方法

文中在分析SAR回波信号模型的基础上，提出一种结合地图分层原理与模板运算提供测试信号的快速仿真方法。     

基于JPEG的SAR图像压缩的C语言实现

在对通用软件的提炼、修改基础上，用标准C语言实现基于JPEG的SAR图像数的压缩，实验结果证明相对其它可实现SAR图像压缩的方法，JPEG压缩性能最佳，同时硬件也容易实现。