Fig. 1. Diagram illustrating refraction in a homogeneous spherical whole-layer atmosphere

Fig. 2. Diagram illustrating refraction in a spherical multiple-layer atmosphere

Fig. 3. Diagram illustrating the elongation of the optical ray trajectory caused by atmospheric refraction

Fig. 4. Atmospheric parameter profiles and refraction calculations in the U.S. standard atmosphere

Fig. 5. The deviation of the refraction angle calculated by different refraction models and the direct integration as a function of zenith angle in the U.S. standard atmosphere

Fig. 6. The variation curve of refraction angle as a function of the number of atmospheric layers，which is calculated by the method of the equivalent refractive index ray tracing and the equivalent curvature one

Fig. 7. The variation curves of the calculation time of different refraction calculation models as a function of the number of zenith angles and the time histograms of different theoretical refraction calculation models in the regime of calculating 91 zenith angles

Fig. 8. Atmospheric temperature profile，pressure profile and relative humidity profile in the morning and night of a day of the northwest area and southeast coast of China

Fig. 9. Refractive index profiles，refractive index gradient profiles calculated from the Ciddor model in the morning and night of a day of the northwest area and southeast coast of China

Fig. 10. The variation curve of refraction angle as a function of zenith angle for different observation altitudes in the morning and night of a day of the northwest area and southeast coast of China using the Cassini model and the equivalent refractive index ray tracing method

Fig. 11. The variation curve of refraction angle as a function of zenith angle for different values of wavelength in the morning and night of a day of the northwest area and southeast coast of China using the Cassini model and the equivalent refractive index ray tracing method

Fig. 12. The deviation of refraction angle calculated at two wavelengths as a function of zenith angle under different values of wavelength in the morning and night of a day of the northwest area and southeast coast of China using the Cassini model and the equivalent refractive index ray tracing method

Fig. 13. The variation curve of refraction angle error as a function of zenith angle under different input parameter errors corresponding to different parameters in the morning of the northwest area of China calculated using the Cassini model and the equivalent refractive index ray tracing method

Fig. 14. The variation curve of refraction angle error as a function of zenith angle under different input parameter errors corresponding to different parameters in the evening of the northwest area of China calculated using the Cassini model and the equivalent refractive index ray tracing method

Fig. 15. The variation curve of refraction angle error as a function of zenith angle under different input parameter errors corresponding to different parameters in the morning of the southwest coast of China calculated using the Cassini model and the equivalent refractive index ray tracing method

Fig. 16. The variation curve of refraction angle error as a function of zenith angle under different input parameter errors corresponding to different parameters in the evening of the southwest coast of China calculated using the Cassini model and the equivalent refractive index ray tracing method

Fig. 17. The variation curve of dispersion angle as a function of zenith angle for different observation altitudes in the morning and night of a day of the northwest area and southeast coast of China using the Cassini model and the equivalent refractive index ray tracing method

Fig. 18. The variation curves of lateral shift as a function of zenith angle under different observation heights in the morning and evening of the northwest area and southeast coast of China

Fig. 19. The deviation of lateral shift calculated at two wavelengths as a function of zenith angle under different values of wavelength in the morning and night of the northwest area and southeast coast of China

Fig. 20. The variation curves of path elongation ratio and path delay as a function of zenith angle under different observation heights in the morning and evening of the northwest area and southeast coast of China

Fig. 21. The deviation of the path elongation ratio calculated at two wavelengths as a function of zenith angle under different values of wavelength in the morning and night of the northwest area and southeast coast of China

Fig. 22. The deviation of the path delay calculated at two wavelengths as a function of zenith angle under different values of wavelength in the morning and night of the northwest area and southeast coast of China