光斑尺寸对光轴检测的约束分析及验证试验

入射激光光轴检测分辨率主要由固有分辨率和细分精度两部分组成,但大气信道二次调制会直接引入误差进而影响光轴检测的检测精度.为了降低光轴检测系统对大气信道环境的敏感程度,首先CCD光轴检测系统和四象限(4QD)光轴检测系统作为两种典型的光轴检测系统其检测模型被分析,并推导在大气环境中其分辨率、固有分辨率、细分精度与光斑尺寸之间的关系.接着以4QD检测模型为例,指出信标光的信噪比和光轴偏移量是影响光轴检测系统的重要技术参数.最后通过一个野外光轴准试验验证了光轴细分精度对大气干扰敏感,而固有分辨率受大气影响不大,可以改变光斑尺寸来改善光轴检测系统对大气干扰的敏感程度.

Spot size on the optical axis detection of constraint analysis and verification tests

Axis detection resolution was divided into two sections, the first being the inherent optical resolution of the case and the second the case subdivided accuracy, however, atmospheric channel secondary modulation can directly introduced into detection error, and moreover, influence detection precision. In order to reduce sensitive degree of axis detection system for atmospheric interference, firstly, CCD system and 4QD system as two typical axis detection models were analyzed; the relationship among resolution and inherent optical resolution and subdivided accuracy and beam length was deduced. Afterwards, based on the example of 4QD axis detection system, through the analysis of restricted constraint condition of four-quadrant electro-optical inspection model in atmospheric channel,SNR of distortions and axis offset are two main technical parameters to affect electro-optical inspection system. Finally, the point, subdivided accuracy of axis detection was sensitive to atmospheric interference and inherent optical resolution was little influenced by atmospheric interference. Therefore, changing beam length can improve sensitive degree of axis detection system for atmospheric interference.