星点质心检测是星模拟器检测技术中的关键技术之一,针对传统处理算法中运算量大、复杂度高、速度慢的问题,提出了一种基于FPGA的单星模拟器质心检测新算法.通过星图预处理和星点提取算法去除噪声,采用平方质心算法计算星点亚像素坐标,并设计了硬件体系结构,完成了高斯滤波、星点提取、质心计算等模块的设计,实现了星图流水化处理,提高了质心检测速度.测试结果表明,星点质心检测的误差小于0.1 pixel,可通过单次扫描无须图像缓存即可计算出质心坐标,极大地提高了处理速度,过程中无须消耗RAM存储器资源,大大节省了存储空间.

为提高静态星模拟器对无穷远处星空的模拟精度以满足星敏感器地面标定需要,提出一种长出瞳距静态星模拟器准直光学系统的设计方案.首先结合星敏感器地面测试要求得到星模拟器技术指标,进而计算得到准直光学系统的设计参数,其次选取埃尔弗目镜作为初始结构,通过Zemax软件进行设计优化,主要针对系统的畸变进行约束,最终设计结果为:视场 6°,焦距 343.77 mm,出瞳距 1 000 mm,全视场范围内畸变小于 0.027 6%,MTF接近衍射极限,结合公差分析结果,表明系统成像质量较高且具备良好的稳定性.最后通过对静态星模拟器星点位置误差的计算分析,得到系统的星光出射精度优于6.16″,能够实现在长出瞳距下对无穷远处星空的高精度模拟.

针对传统数字光处理(D M D)投影仪镜头体积较大、像质不高以及无偏轴带来的使用不便等问题,基于完全非对称式反远距型光学系统初始结构设计了一款适用于对角线1.19 cm(1920 pix×1080 pix)的DMD投影仪镜头,解决了后工作距离长、畸变小、分辨率高等设计难点,用ZEMAX进行优化,并进行公差分析,结果表明,在工作波长459～618 nm谱段范围内,分辨率极限93 lp/mm(截止频率)处,其调制传递函数(MTF)在边缘视场优于0.4,全视场畸变绝对值≤1.1％,此设计结果具有体积小、使用方便、像质优良、结构紧凑等优势,符合实际使用要求.

为了满足现代红外探测器的性能测试与评估,基于DMD(数字微镜阵列)的工作原理,设计了一种工作在3～5μm和8～12μm双波段,具有大孔径、长出瞳距的红外双波段景象模拟器的光学系统.光学系统由照明系统、棱镜、DMD和投影物镜组成,其中照明系统采用双片式结构,其均匀性达到94％,通过采用TIR棱镜,有效地增加了系统能量利用率.系统焦距为200 mm,半视场角为2.5°,出瞳直径为90 mm,出瞳距为300 mm.最终优化结果显示在截止频率17 lp/mm处,光学系统长波红外MTF大于0.7,在截止频率17 lp/mm处中波红外MTF大于0.5,设计结果接近衍射极限,系统畸变小于0.05％,成像质量良好.

为满足大视场高精度星敏感器的标定任务,解决星模拟器对星表检索量大速度过慢等问题,提出了一种基于20° ×20°视场星模拟器的外切圆形分区检索导航星算法,将星表分为144个子区,通过光轴指向子区的具体位置,确定视场所占的对应子区的编号及个数,筛选并提取子区内的导航星.通过编写测试软件载入15914颗星的SAO星表进行验证,测试结果表明该算法使星图平均刷新率达到106 Hz,与传统遍历算法相比提升明显,且与目前较先进的高刷新率算法水平相近;通过在同视轴坐标下,将该算法生成的星图与遍历星表算法生成的星图和Stellarium星图做对比,三幅星图的星点位置相同,验证了算法的准确性.

The star simulator was designed to simulate the physical characteristics of real stars. Due to the different color temperatures and magnitudes of different stars, in order to simulate stars more realistically, a starlight source simulation system was required to achieve large-scale high-precision adjustment of color temperature and magnitude. The system consisted of an integrating sphere, light source module, control module and fiber spectrometer to form a closed-loop light source simulation system. In order to ensure the uniformity of the emitted light, a bromotungsten lamp and a variety of monochromatic LED mixed light were used as the light source, and the output brightness of the LED was controlled by constant current driving. The quantum behavior particle swarm algorithm was introduced as the spectrum matching algorithm to solve the LED coefficient ai. As the number of iterations increases, and the value of the fitness function reached the minimum, the simulation error of color temperature and magnitude became smaller. Experimental verification: The range of color temperature was 3 000, 4 300, 5 500, 6 500, 7 600, 20 000 K, the color temperature matching error was better than ±10%; the range of simulated magnitude was +2-+8.5 Mi, and the magnitude matching error was better than ±6%.

In order to improve the simulation accuary of the static star simulator for the stars at "infinity",an optical system design scheme of the static star simulator for the high-precision simulation of the stars at "infinity" was pro-posed by studying the influence of the collimating optical system on the measurement accuracy of the star simulator. Firstly,according to the ground calibration requirements of the star sensor,the design parameters of the optical system of the star simulator were obtained;and the optical system with high imaging quality was designed by using ZEMAX software. The final design results are got that focal length is 248.989 mm;spectral range is 500～800 nm;effective ap-erture is 65mm;and field of view is 10°.Then the image quality of the aberration curves produced by the designed col-limating optical system is analyzed. The results shows that the distortion value in the 10° field of view is less than 0.05% and the RMS radius of each field of view is less than the diffuse spot size,which the technical specifications are satisfied. Finally,the Leica theodolite 6100A is used to test the star points on the star point board. The test data shows that the inter-satellite angular error is better than 10″,which achieves high-precision simulation of the star at‘infinity’.

The Star sensor is a kind of high precision attitude measurement device, which determines the attitude of the carrier by detecting stars at different positions on the celestial sphere. In order to test the function of the star sen-sor on the ground,in this paper,the software of the ground star map simulation detection system was designed which made the star map simulation system and the star sensor test system form a closed-loop test;and the quasi-determin-istic attitude test experiment of the star sensor was completed. The SAO catalog of 58928 stars was used in the ground star map simulation system for retrieval. According to the traditional global star traversal method,the total time of star point retrieval and map refresh was about 200ms,which did not meet the index requirement that the star map refresh time was higher than 10Hz. By means of physical partition of the entire star table,the original star table was divided into 16 sub-regions according to longitude and latitude. The average number of each sub-region was less than 4000. The corresponding sub-regions was imported according to the optical axis and generated the corresponding star map in the software, which greatly reduced the time required for star traversal. Experimental results showed that the star map simulation detection system can complete the high dynamic test of the star sensor attitude. After the catalog partition retrieval,the refresh time of the star map simulation was increased to more than 40ms (25Hz),which realiz-es the high dynamic attitude test function of the star sensor.