基于像素复用的SPAD阵列连续扫描三维成像

Continuous scanning 3D imaging with SPAD array based on pixel multiplexing

基于单光子雪崩二极管(Single-photon avalanched diode,SPAD)阵列探测器的激光雷达系统具有单光子探测灵敏度、高时间分辨率及探测速率快等优点,在遥感测绘、目标识别和航天器着陆等领域具有广泛的应用前景。受限于当前SPAD阵列器件的较小像素规模和普遍存在的热像素等缺点,直接采用SPAD阵列所获取的三维图像质量差且成像范围小。提出了一种基于像素复用的SPAD阵列连续扫描三维成像方法以扩展成像范围,同时通过像素信息复用增加同一目标点的累积探测次数,以提高距离测量精度和三维成像质量。基于32×32规模SPAD阵列搭建了推扫式三维成像实验系统,通过对3.3 m外目标进行一维连续扫描成像实验,利用所提方法实现了快速大范围的光子计数三维成像(32×520/7 s),同时有效改善了热像素对成像结果的影响,三维图像的平面精度达2.3 mm。

Lidar systems based on single-photon avalanched diode(SPAD)array detector not only have high sensitivity and time resolution,but also have high detection rate.It has wide application prospects in the fields of remote sensing mapping,target recognition,spacecraft landing and so on.Due to the shortcomings of the current SPAD array devices,such as the small pixel format and the hot pixel problems,the quality of the three-dimensional(3 D)images obtained by directly using the SPAD array is poor and the imaging area is small.A continuous scanning three-dimensional imaging method with SPAD array based on pixel multiplexing was proposed to expand the imaging area.At the same time,the multiplexing of pixel information could increase the cumulative detection times of the same target point,thereby improving the depth measurement accuracy and the 3 D imaging quality.A push-broom imaging experimental system was established based on a 32×32 SPAD array.By performing a one-dimensional continuous scanning imaging experiment on a target 3.3 m away,a fast and large-scale photon counting3 D imaging(32 rows×520 columns/7 s)was achieved.Meanwhile,the influence of hot pixels on the imaging results is effectively alleviated,and the plane accuracy of the three-dimensional image achieves2.3 mm.