针对VCSEL型脉冲激光雷达电路在上电阶段产生大的浪涌电流的现象,研究了一种浪涌降低方法,通过增加上电控制,将上电方式由直接上电改为间接上电,使得瞬间释放的大的浪涌电流间断释放,每次产生的浪涌电流远小于瞬间释放的大电流.通过试验验证,可以将瞬间上电产生的17.3 A浪涌电流,减小到每次上电小于5A,并且没有引入新的限流电阻等器件.此方法能够在不改变光源工作性能的基础上,有效地抑制上电浪涌电流,保护了供电模块.

卫星在轨工作时因尘埃撞击、作动机构动作引起的颤振的高精度准确测量,对实现振动补偿、图像修正,进而提升遥感卫星的对地分辨率具有重要意义.本文基于FPGA和1553B总线的架构,设计了用于在轨卫星颤振测量的数据采集系统,对系统的多路同步采集、存储、传送以及抗辐射可靠性等关键问题进行了详细分析和设计,并通过硬件设计实现及试验验证了系统的功能.测试结果表明所涉及的数据采集系统样机满足星载测试要求.

高动态条件下星点提取有两个难点:一是暗弱星点目标湮没在噪声中不易识别,质心定位精度较差;二是星点像斑可能断裂,无法用常用的连通域算法提取.针对上述难点,建立了高动态条件下星点像斑模型,提出了基于该模型的像斑补偿与质心定位提取算法.该方法分为四步:第一,利用卡尔曼滤波实现星点像斑静态模板的实时迭代;第二,基于静态模型与星点运动模糊模型建立星点像斑动态模型;第三,以动态模型作为模板在恒星跟踪窗口内进行相关性匹配以确定星点像斑位置;第四,基于动态模型补偿星点像斑,并计算质心位置.实验结果表明,该方法能有效解决高动态条件下暗弱星点提取与断裂残损星点修复问题.相比传统算法,姿态精度误差均值减少了40.9％,最大误差减少了81.2％;星点提取率达到100％,提高174.5％,提取星数相比阈值分割与连通域法提高了173％.

In view of limitations of the Gaussian model for describing star energy distribution, based on the radiation characteristic of stars and the imaging properties of star tracker, an improved skewed normal distribution model of star imaging was proposed and its key parameter vector was determined. The Kalman filtering was designed to estimate the characteristics of star spot. Then, based on the characteristic that the stellar imaging process of star sensor is a stationary random process, the state space composed of the characteristic of star spot was established and the optimal estimation value of the characteristics in the least square sense was obtained. Finally, the parameter optimization of star point imaging model was achieved by using look-up table method. The result of the ground star observation shows that the Kalman filter can estimate the characteristic quantity quickly and effectively. Compared with the Gaussian model, the improved skewed normal distribution model has higher simulation accuracy for the energy distribution of the star spot.