共查询到20条相似文献,搜索用时 46 毫秒
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双基地ISAR成像中,一维距离像分辨率不仅受发射信号带宽限制,同时还受制于成像双基地角,最终导致双基地ISAR距离像分辨率远低于同等带宽的单基地ISAR。为了解决双基地角造成的一维距离像分辨率下降问题,在研究双基地ISAR目标基带回波稀疏性的基础上,提出了利用目标基带回波信号稀疏分解系数生成一维距离像的方法。构建稀疏分解冗余基的等效延迟时间单元越短,则距离像分辨率越高,基于此思路,首先构造出与半双基地角余弦成正比,且与发射信号带宽成反比的延迟时间单元,然后利用此延迟时间单元构建冗余基,最后基于推广的正则化FOCUSS算法估计基带信号的稀疏表示,得到分辨率不受双基地角影响的目标一维距离像。空间目标理想散射点的仿真实验验证了算法的有效性。 相似文献
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基于二次距离压缩的双基地合成孔径雷达斜视成像算法 总被引:2,自引:1,他引:1
根据Tandem模式双基地SAR几何关系及其信号模型,该文给出了一种适用于该模式下的基于二次距离压缩的斜视成像算法,成功地解决了由于接收、发射平台分置而产生的不同于单基地SAR的二次距离压缩、距离徙动校正和方位聚焦问题。仿真表明在任意双基地角情况下,该算法均能得到很好的成像结果。 相似文献
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双站合成孔径雷达(SAR)具有隐蔽性和反侦察等优点,但对于双站SAR方位向移变结构的成像研究较少。本文提出了一种基于双站平飞移变模式下改进的双站SAR线性调频尺度成像算法(CS)。该CS算法利用了一种将双站回波等效为单站回波处理的简化方法,引入了收发双站速度比因子,可在双站速度比值不超过1.5的情况下较好地成像,并通过仿真和对实际数据的处理验证了算法的有效性。 相似文献
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This paper discusses reconstruction of three-dimensional surfaces from multiple bistatic synthetic aperture radar (SAR) images. Techniques for surface reconstruction from multiple monostatic SAR images already exist, including interferometric processing and stereo SAR. We generalize these methods to obtain algorithms for bistatic interferometric SAR and bistatic stereo SAR. We also propose a framework for predicting the performance of our multistatic stereo SAR algorithm, and, from this framework, we suggest a metric for use in planning strategic deployment of multistatic assets. 相似文献
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针对发射机固定的斜视双基地SAR新成像雷达体制,建立了雷达信号的回波模型,推导了此模型下的非线性Chirp Scaling算法(NLCSA)。仿真证明,该算法可对双基地SAR在较大的斜视角下,不进行插值操作而实现精确的距离徙动枝正,得到聚焦良好的SAR图像,其处理速度快,非常适合斜视双基地SAR的高速并行信号处理。 相似文献
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双站合成孔径雷达(Synthetic Aperture Radar,SAR)的回波距离历程比单站SAR复杂,导致双站SAR的Chirp Scaling算法的三个成像因子的推导困难,计算量大.现在的诸多双站SAR处理方法是针对双站SAR回波特性进行处理,文中通过双站SAR距离历程变换和引入收发双站速度比因子,将双站SAR回波等效为单站SAR回波进行处理,并对等效误差在双站SAR平飞移不变模式和移变模式下进行了分析,为双站SAR成像等效变换处理的参数选取提供了指导. 相似文献
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双基地逆合成孔径(ISAR)成像中,一维距离像的分辨率因双基地角的存在而下降,为解决此问题,研究了双基地ISAR的一维距离成像算法。在分析复基带回波稀疏特性的基础上,将一维距离像的生成问题转化为噪声环境下信号的稀疏分解问题。利用可任意调节的时延单元构建冗余基,基于L曲线准则估计正则参数,最后利用推广的正则化FOCUSS算法估计复基带回波的稀疏分解系数,并据此生成目标的一维距离像。一维距离像分辨率取决于构建稀疏分解冗余基的延时单元,据此解决了双基地角对距离分辨率的限制问题,仿真实验验证了算法的有效性。 相似文献
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A metric is proposed that allows reliable prediction of the maximum bistatic angle for which the monostatic-to-bistatic equivalence theorem (MBET) can be used. Currently, the theorem leaves the term “sufficiently smooth” undefined, making selection of the maximum angle somewhat subjective. The proposed metric provides a quantitative evaluation of complexity/smoothness, and relates this to an angle limit based on an empirically derived statistical error profile. That is, the metric allows prediction of the maximum bistatic angle for which the MBET provides less than a 1.5 dB error at a confidence level of 95%. Although the metric is presently only demonstrated for two-dimensional (2D) objects at a single polarization and error value, sufficient experiments following the same process can easily extend the method to three-dimensional objects, arbitrary polarizations, and alternate error tolerances. Such a capability allows for optimization of either monostatic collections used for prediction of bistatic data sets, or bistatic computations interpolated to monostatic results 相似文献
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由发射机(T)和接收机(Rm)共站的单基地高频地波雷达增设分置的接收系统(Rb)构成的T/Rm-Rb双基地高频地波雷达系统用于海洋环境监测时,既可测得矢量流速度,又可消除风向模糊性,是目前高频地波雷达的发展趋势之一。该文首次从T/Rm-Rb系统的探测能力与海流测量误差两方面分析最佳基线长度和最佳双基地角范围,从而确定其布站原则,即:在确定T/Rm单基地雷达的位置后,先根据T-Rb双基地雷达设计指标中的最大探测距离和确定基线长度,然后根据T/Rm-Rb系统海流测量误差最小的原则确定最佳双基地角范围,从而确定T-Rb双基地雷达接收站Rb的位置。该布站原则可为双(多)基地高频地波雷达的海洋环境监测应用提供参考和依据。 相似文献
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On the derivation of bistatic RCS from monostatic measurements 总被引:1,自引:0,他引:1
The factors which govern bistatic scattering are discussed and the relations between bistatic and monostatic scattering are presented in terms of the combined effect of individual scattering centers on the target. The concept of reradiation lobe patterns of the individual scattering centers is used to define the bistatic pattern in terms of the monostatic pattern and the bistatic angle β. Analytical arguments then demonstrate that for small bistatic angles, the bistatic RCS is very closely approximated by the monostatic RCS measured on the bisector of the bistatic angle and measured at a frequency lower than the true frequency by the factor cos β/2. The limitations to this approximation which are based on the angular width of the lobe patterns reradiated from individual scattering centers are noted. The approximation is of particular value in translating measured monostatic RCS values into bistatic RCS for small bistatic angles. 相似文献
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