Fig. 1. Schematic diagram of SSP

Fig. 2. Schematic diagram of the optical platform

Fig. 3. Schematic diagram of tracking system operation

Fig. 4. Fisheye images. (a) Black and white checkerboard image; (b) Corner detection image; (c) Correction image of checkerboard

Fig. 5. Measurement flow chart

Fig. 6. Measuring electrical signal. (a) Shipboard sun-photometer; (b) POM-01 MKⅢ sun-photometer

Fig. 7. Change of atmospheric vertical transmittance

Fig. 8. Ångström index figure

Fig. 9. Comparison of data between SSP and POM-01 sun-photometer. (a) 940 nm atmospheric transmittance; (b) PWV