Fig. 1. Structural diagram of optical system

Fig. 2. Test site image of DPC

Fig. 3. Original image of DPC

Fig. 4. Flow chart of data processing of DPC

Fig. 5. Data processing results of DPC. (a) Degree of polarization of sky under 670 nm; (b) radiation luminance of sky under 670 nm

Fig. 6. Working diagram of CE318N. (a) Schematic of SPP interscan; (b) test site image

Fig. 7. Data processing results of CE318N. (a) Degree of polarization of sky; (b) radiation luminance of sky

Fig. 8. Data comparison of DPC and CE318N. (a) Degree of polarization; (b) radiation luminance

Fig. 9. Spectral distributions of integrating sphere and sky scattered light

Fig. 10. Spectral response curve of DPC for 865 nm channel

Fig. 11. Response curves within different spectral bandwidths for 865 nm channel

Fig. 12. Spectral response curves of DPC and CE318 instruments. (a) 490 nm channel; (b) 670 nm channel; (c) 865 nm channel

Fig. 13. Relative error of measurement induced by visual field mismatch

Fig. 14. Radiation luminance comparison between DPC and CE318N

Fig. 15. Schematic of test of absolute radiation calibration coefficient difference