提出了一种相机在回路的星空背景数字图像生成方法。依据光度量与辐射度量的关系,建立恒星成像信号强度模型,计算目标在焦面的成像强度。通过星图软件SKYMAP对天区内恒星数目及星等进行统计,拟合得到相机观测视场内恒星数目与星等的统计函数。使用该统计函数模拟相机视场内的恒星数目及其对应的星等。最后,基于成像信号强度模型、恒星数目及星等的统计函数以及恒星在焦面的成像特性,提出全天区统计的星空背景数字图像生成方法。基于具体的相机CCD与光学系统参数,对星空背景数字图像生成方法进行仿真验证。结果表明,该方法可生成较大星等(星等＞10)的星空背景图像,基本满足了现有空间目标检测与跟踪算法对星空背景数据的要求。

A digital image generating method based on the CCD and optical parameters of sensor system was presented. According to the relation of photometry and radiometry, a model of star imaging gray value was produced to calculate the imaging intensity for target in focal plane. Then, the number and magnitude of stars in the space were counted to obtain the statistic regularity of stars in the field of view by star map software SKYMAP. Finally, the digital image generating method was set up acoording to the statistic regularity of stars in the space and star image characteristic on CCD focal plane.The digital image generating method was simulated based on CCD and optical system parameter, results show that the method can generate a star map with higher apparent magnitude (magnitude＞10) and can satisfy the requirements of space object detection and surveillance for star map.