太赫兹后向散射强度是描述目标对太赫兹散射能力的一个重要参数。首先通过测量校准目标验证了2.52 THz后向散射特性测量系统的可行性, 并测得了系统的信噪比。在此基础上, 对6种尺寸铣削和喷砂加工矩形铝板的相对后向散射强度进行测量, 测量范围为0°~3°。实验结果表明: 测量的最大动态范围为32.25 dB; 不同尺寸喷砂铝板的相对后向散射强度之差较铣削铝板更明显; 在0°处, 相同表面积的铣削和喷砂铝板回波的平均偏差分别约为1.35 dB和0.51 dB。

Terahertz back scattering intensity is a very important index to represent the scattering ability of targets to terahertz. Firstly, the feasibility of 2.52 THz back scattering properties measurement system is proved by the measurement of the calibration target, and the signal-to-noise ratio of the system is measured. The relative back scattering intensities of rectangular milling and sand blasting aluminum plate with six kinds of sizes are measured in the measurement range of 0°-3°. The experiment results show that the measured maximum dynamic range is 32.25 dB, back scattering intensity difference between sand blasting aluminum plate with different sizes is more obvious than that between milling aluminum plate, the average errors of milling and sand blasting aluminum plates with same surface area at 0° are 1.35 dB and 0.51 dB, respectively.