共查询到20条相似文献,搜索用时 109 毫秒
1.
2.
在距离-多卜勒成象雷达中,为获得高多卜勒频率分辨力,要求有一定的积累时间,而在这段时间内,旋转目标上的点有可能移动若干个距离单元和多卜勒分辨单元,因而会引起图象模糊。这种移动可以通过存贮经过适当处理的回波脉冲来加以补偿,而角坐标是由雷达天线的角坐标确定的。由此产生的存贮数据表示目标反射率密度的三维付立叶变换,因此可用反付立叶变换来处理。文中还分析了发射源和接收机位置分开的三维雷达/目标的几何关系。研究了各种系统畸变的影响,并给出了从微波试验埸获得的证明图象质量改善的试验结果。 相似文献
3.
基于Stolt偏移的探地雷达合成孔径成像研究 总被引:11,自引:4,他引:7
对探地雷达数据进行合成孔径处理可提高探地雷达图像的分辨力,有利于对地下目标的探测及精确定位.文中提出了一种新的stolt偏移插值实现方法,用于探地雷达合成孔径成像,它能克服传统方法中偏移能量不集中的缺点并保持处理速度快的优点,通过对实测数据进行处理,其结果表明该方法取得了很好的效果. 相似文献
4.
基于最大熵法的雷达图像分割 总被引:1,自引:0,他引:1
介绍了雷达扫描的视频图像中的目标提取方法.首先需要在雷达扫描图像中将回波目标从信号的背景噪声中分割出来,笔者认为基于阈值分割的方法是一种适合文中提到的雷达扫描视频图像分割的方法,并且简单易于工程实现.文中利用最大熵的阈值分割法将目标从雷达图像中分割出来,这种方法较其它阈值分割法更适合于应用在文中提到的雷达扫描视频图像中. 相似文献
5.
本文讨论用雷达信号处理来改进方位角分辨力的问题。在既需要高的角度分辨力又要求天线具有较宽的主瓣宽度的场合,这样的问题是存在的。文章考察了这种方法在航管搜索雷达上的某些应用,并分析了方位角的几种估算方法,最后给出了计算机模拟结果,并作了评价. 相似文献
6.
7.
文中基于数字波束合成体制的相控阵雷达,研究改善传统单脉冲体制雷达性能的方法。提出了一种基于一组同时数字多波束处理的新方法。文中证明该方法可以将单脉冲测角方法和极大似然估计测角算法进行性能的平衡。该方法利用了基于同时数字多波束形成技术以及多种处理算法。计算机仿真试验证明该方法可以在提升雷达目标检测和测角性能的同时有效的改善波束形状损失。 相似文献
8.
基于对目标分辨力和目标识别的要求,高分辨力的微波全息成像手段越来越受到重视。现代战争电子对抗的要求又使双基地雷达具有更好的发展前景。因此,采用双基地合成孔径雷达较好地满足了上述需求。成为现代雷达技术的重要研究领域。该形式的雷达角分辨力是衡量其性能的一个重要指标,本文推导了常见的同步运动的双基正侧视合成孔径雷达的角分辨力公式,给出了一些比较性结论。 相似文献
9.
AN/APS—116雷达系统是由美国海军为海洋监视和反潜战侦察而研制的.基本系统的要求是在强干扰信号形式海面杂波后向散射条件下可靠地探测小潜望镜那样大小的目标。雷达系统的设计方法采用了高距离分辨力和快速扫描天线。信号处理方案是采用扫描—扫描去相关来实现的,M/N门限用于目标测探。本文还包括了雷达每个主要元件的简短介绍,以及验证本系统性能的鉴定测试概况. 相似文献
10.
边扫描边跟踪是机扫机载PD火控雷达用于多目标跟踪和多目标攻击的主要工作方式。由于天线处于扫描状态,难以使用单脉冲法测量目标的方位角,目前采用的测角方法具有较大的测量误差。文中提出了一种基于目标幅度包络分析的测角方法,能提高目标方位角测量精度。试验验证了该方法的有效性和可行性。 相似文献
11.
Compared to synthetic aperture radars (SARs), the angular resolution of microwave radiometers is quite poor. Traditionally, it has been limited by the physical size of the antenna. However, the angular resolution can be improved by means of aperture synthesis interferometric techniques. A narrow beam is synthesized during the image formation processing of the cross-correlations measured at zero-lag between pairs of signals collected by an array of antennas. The angular resolution is then determined by the maximum antenna spacing normalized to the wavelength (baseline). The next step in improving the angular resolution is the Doppler-Radiometer, somehow related to the super-synthesis radiometers and the Radiometer-SAR. This paper presents the concept of a three-antenna Doppler-Radiometer for 2D imaging. The performance of this instrument is evaluated in terms of angular/spatial resolution and radiometric sensitivity, and an L-band illustrative example is presented 相似文献
12.
Munoz-Ferreras J.M. Perez-Martinez F. Calvo-Gallego J. Asensio-Lopez A. Dorta-Naranjo B.P. Blanco-del-Campo A. 《Geoscience and Remote Sensing, IEEE Transactions on》2008,46(6):1624-1633
Traffic surveillance is an important civilian application of radars. The current high-resolution radars give new opportunities so that the traffic application may be redefined. In this paper, a traffic scenario with a high-resolution radar is presented. A range-bin alignment method, the Global Range Alignment, which comes from the focusing techniques in inverse synthetic aperture radar, is applied to obtain further capabilities than the usual velocity measurement: distinction between vehicle types via length estimation and adequate management in situations with simultaneous targets. Preliminary results from a real scenario using a high-resolution linear frequency-modulated continuous-wave millimeter-wave radar are shown. 相似文献
13.
《Electronics & Communication Engineering Journal》1993,5(1):3-12
High-performance synthetic aperture radars (SARs) for mapping demand massive digital signal processing powers. The fall in the cost of computing devices has recently passed the point at which such processors can be afforded and SARs are now being used in a range of applications. The analogous inverse synthetic aperture radar (ISAR), which enables moving targets to be imaged by stationary or moving radars, is also becoming widely used. The unifying principle underlying SARs and ISARs is presented and the common parameters defining the performances of both types of radar are derived. A novel technique is described which enables the radar to measure the random angular spin of a ship at sea, thereby permitting it to be imaged deterministically by ISAR. Results are presented from a representative selection of ISARs and SARs ranging from the imaging of model targets by ISARs operating at scaled-up frequencies through to the mapping of the surface of Venus by a satellite SAR. The paper concludes with a review of likely future developments of these types of radar and suggests that further major advances are possible 相似文献
14.
提出了一种利用最小冗余非均匀线性阵列对多输入多输出(MIMO)雷达系统进行阵列配置优化从而提高参数估计性能的方法。文中从MIMO雷达信号模型出发,分析了均匀线性阵列与非均匀线性阵列两种配置下,MIMO雷达系统获得的虚拟阵元数的差异,给出了一种在物理阵元数量较大时最小冗余非均匀线性阵列的生成方法。仿真结果表明:最小冗余线性阵列能够利用较少的物理阵元个数获得与均匀线性阵列相同的参数估计性能。而在物理阵元个数相同的情况下,最小冗余非均匀线性阵列MIMO雷达可以获得更多的虚拟阵元、更好的参数估计性能和更低的克拉美·罗界。 相似文献
15.
A method of measuring angle of arrival, or angle of fire, of a microwave signal transmitted over a short line-of-sight path is described. The method used is similar to that employed in conical scan, or simultaneous lobing, radars. Accuracy in angular measurement is achieved by utilizing the portion of the antenna pattern in which the gain function varies rapidly with angle. Using 4-ft aperture antennas operating at 35 GHz on a6frac{1}{2} -mi path, angle of fire is detected linearly with an accuracy ofpm 0.010deg , and the resolution may be as good aspm 0.002deg . The effects of random atmospheric turbulence on the results is investigated. Many examples of layered structure have been observed, but the most dramatic records come when the atmosphere is unstable and large changes in refraction occur, e.g., at the onset of land and sea breezes. 相似文献
16.
17.
18.
19.
测角精度是机载火控雷达的重要指标。分析了在单目标跟踪(STT)状态下雷达的测角误差的产生,给出了理论推算方法和工程计算结果,通过分析验证提出了提高测角精度的途径。 相似文献