This paper considers two methods for improving the visibility of hidden objects in radar tomography using nonlinear time transformations of short ultra-wideband (UWB) pulses. The first method is based on selection of a digital coherent jitter formed by special nonlinear signal transformation. The resulting increase in the contribution of high-frequency components to the reflected signal spectrum improves the spatial resolution of images of hidden objects. The second method uses relatively powerful monochromatic side irradiation in the clocked mode to detect a target. This leads to a characteristic distortion of the radar sensing pulse reflected from nonlinear radio-electronic elements – parts of the target being located. The observed change in the radar pulse waveform allows selective tomography of nonlinear radio-electronic elements to be carried out.

中文翻译：

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雷达断层扫描中脉冲信号的非线性变换

本文考虑使用短超宽带 (UWB) 脉冲的非线性时间变换来提高雷达断层扫描中隐藏物体的可见性的两种方法。第一种方法基于选择由特殊非线性信号变换形成的数字相干抖动。由此产生的高频分量对反射信号频谱贡献的增加提高了隐藏物体图像的空间分辨率。第二种方法在时钟模式下使用相对强大的单色侧面照射来检测目标。这会导致从非线性无线电电子元件（被定位目标的一部分）反射的雷达感应脉冲的特征失真。