Influence of Threshold Segmentation on Star Pair Angular Separation Measurement Accuracy

Threshold segmentation and star extraction are important parts of star image processing, the threshold value not only influences the number of segmentation-derived stars but also has a great impact on the accuracy of subsequent star positioning. According to the disadvantages of common threshold segmentation algorithms, a kind of weighted iterative threshold algorithm was put forward, which introduces two weight factors and can obtain suitable threshold value for segmentation and number of stars meeting requirements through selecting suitable weight values. With star image acquired by CCD camera as the experimental target, we compared the accuracy of star pair angular separation at different threshold values for segmentation, and verified that our method has an improved effect, compared with the traditional iterative threshold algorithm.