Acta Geodaetica et Cartographica Sinica ›› 2024, Vol. 53 ›› Issue (11): 2166-2177.doi: 10.11947/j.AGCS.2024.20230521

• Geodesy and Navigation • Previous Articles    

A method for star extraction from daytime star maps with additional correction of eastern elongation

Wanxiang GOU(), Chonghui LI(), Shuai TONG, Yong ZHENG, Yuan YANG, Zhixing CHEN, Yinhu ZHAN   

  1. Information Engineering University, Zhengzhou 450000, China
  • Received:2023-11-24 Published:2024-12-13
  • Contact: Chonghui LI E-mail:memgwa201611@163.com;lichonghui6501@126.com
  • About author:GOU Wanxiang (1990—), male, master, majors in celestial navigation, image processing, et al. E-mail: memgwa201611@163.com
  • Supported by:
    The National Natural Science Foundation of China(42374011);Excellent Youth Fund Project of Henan Province(242300421150)

Abstract:

The daytime star map is characterized by high background noise and low signal-to-noise ratio, which lowers the efficiency of traditional star extraction methods. Moreover, robustness of single frame extraction methods is poor due to the negative factors of daytime star map, including star energy weakness, noise sensitivity and star contour irregularity. Therefore, a star extraction method with modification of apparent motion is proposed for daytime infrared star map processing. With application of camera parameter conversion model, image coordinates of the target star were predicted using the data of station position, observation time and ephemeris. Further, relative displacements of the star in image sequence were precisely calculated using the exposure intervals, which led to precise register of the image superposition on star area, and finally resulted to accurate star extraction. Experimental results show that the success rate of star extraction with the proposed method can reach 100%, which is 163% higher than that of traditional algorithms. Meanwhile, the time consumption was reduced to 23%. Signal-to-noise ratio was also enhanced since the influence of random error was greatly reduced, and the centroid extraction accuracy was improved by 72% compared to single frame methods.

Key words: daytime star map, eastern elongation, star extraction, centroid accuracy, astro-geodetic surveying, multiframe overlay

CLC Number: