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合成孔径激光雷达(SAL)能实现远距离目标的高分辨率成像。然而,由于所用激光波长很短,SAL系统中微小机械振动都可能在目标回波信号中引入巨大相位误差,所以,SAL很难实现稳定的相位史数据,高分辨率SAL图像的形成往往要应用额外的相位误差消除技术,特别是相位梯度自聚焦(PGA)技术。演示了一个运转良好的条带模式SAL实验室成像装置。采用一台1 550 nm波段的线性调波长激光器作为探测光源,该装置能够形成聚焦良好的高分辨率图像。通过细致的系统设计,基本抑制了在回波信号中产生相位误差的各种振动。该装置产生的相位史数据非常稳定,高分辨率图像的形成仅需简单遵照标准的SAL成像理论,无需额外借助PGA。采用点目标定标,测量得到该成像装置的方位和距离分辨率接近其理论估计。详细给出了2.4 m距离上多种目标的良好聚焦图像及相应的稳定相位史数据。
Synthetic Aperture Lidar (SAL) enables high-resolution imaging of long-range targets. However, due to the very short laser wavelengths used, small mechanical vibrations in the SAL system can introduce large phase errors into the target echo signal, making SAL difficult to achieve with stable phase history data and high resolution SAL image formation Additional phase error cancellation techniques, especially Phase Gradient Self-Positioning (PGA). Demonstrated a well-functioning strip-mode SAL lab imaging device. A 1 550 nm wavelength-modulated wavelength-modulated laser was used as the probe light source to create a well-focused, high-resolution image. Through careful system design, basically suppressed in the echo signal of the phase error of a variety of vibration. The device produces very stable phase history data and high-resolution image formation simply follows standard SAL imaging theory without the need for additional PGA. Using the point target calibration, the resolution and azimuth resolution of the imaging device are close to their theoretical estimates. The well-focused images and corresponding stable phase history data of various targets at 2.4 m distance are given in detail.