“日盲”紫外增强型CCD的自动增益控制

Automatic gain control of SBUV-ICCD

为使"日盲"紫外增强型电荷耦合器件(SBUV-ICCD)适用于不同辐亮度目标的探测,并避免由于长时间高亮度照射引起的器件损害,提出了适用于SBUV-ICCD的自动增益控制(AGC)算法。应用连续N帧图像直方图求和作为分析对象,将其分为背景段、目标段、明亮段及饱和段,使用明亮段与目标段的比例系数及饱和段与明亮段的比例系数为控制参量,完成了AGC算法,并设计实验对其进行了验证。实验结果表明,通过控制饱和系数<0.2,明亮系数在0.4～0.8内,当目标辐亮度突变或缓慢变化时该算法均能够在1～3s内实现增益的调节,在保护相机的同时使图像具有较好的分辨率。

A Automatic Gain Control（AGC） algorithm for Solar Blind Ultraviolet Enhanced ICCD （SBUV-ICCD） was proposed to detect the targets with different radiation luminances and to avoid damaging the device when it was exposed to high intensity radiation. The sum of N consecutive frame histograms were treated as an analysis object, and it was divided into background section, target section, brightness section and saturated section. The AGC algorithm was accomplished by using the proportion factor of brightness section to target section and the coefficient of saturated section to brightness section as controlling parameters. Finally, experiments were designed for testing the algorithm performance. Through controlling saturate ratio below 0.2 and bright ratio in the range of 0.4 --0.8, experimental results indicate that the algorithm can adjust the gain of ICCD quickly and effectively in 1-3 s whenever the target＇s luminance is up unexpected rapidly or changed slowly, obtained results show that proposed algorithm can offer a good image resulution while the camera is protected.