基于高重复频率脉冲激光的水下全选通成像雷达

Underwater Full Range-Gated Imaging Radar Based on High-Repetition-Rate Pulse Laser

在水下高重复频率距离选通成像系统的基础上,设计了一种全选通成像系统。在空间域中,可将整个探测区域划分为多个相互叠加的改进选通切片,一帧图像积分时间内的激光脉冲按照一定规律分布到各个改进选通切片中;在时间域中,在一帧图像积分时间内按照一定规律实现宽选通门对不同激光脉冲回波的等时差移动,使得一帧图像中包含所有距离的目标信息,实现了全选通实时成像。实验对比了连续光成像系统、传统距离选通成像系统和全选通成像系统的成像质量。实验结果表明,全选通成像系统同时具有连续光成像系统探测范围广和距离选通成像系统探测距离远的优点,探测距离大于4.5 H(H为衰减长度),输出视频的帧率为20Hz。

A full range-gated imaging system is designed based on the underwater high-repetition-rate range-gated imaging system. In the spatial domain, the whole detecting range can be divided into multiple improved gating slices which are superposed mutually, and the laser pulses during the integral time of one image frame are distributed in these improved gating slices according to certain rules. In the time domain, the echo isotime movement of different laser pulses after the wide gate is achieved according to certain rules, the target information of all distances can be integrated into one frame, and the full range-gated images can be obtained in real-time. The imaging quality of the continuous-wave imaging system, the traditional range-gated imaging system and the full range-gated imaging system is compared. The experimental results show that the full range-gated imaging system has advantages of large detection range possessed by the continuous-wave imaging system and long detection distance possessed by the range-gated imaging system. The detecting distance exceeds 4.5H （H is the decay length） and the frame rate of the output video is 20 Hz.