Fig. 1. Tracing analysis of stray light effect in photometric measurement system. (a) Optical ray in ideal photometric measurement system; (b) optical ray in general photometric measurement system

Fig. 2. Varying curves of PST values under different conditions. (a) PST value as a function of off-axis angle; (b) PST value as a function of irradiance

Fig. 3. Principle of three-dimensional ray tracing analysis for photometric measurement system

Fig. 4. RBF network model for error correction of photometric measurement

Fig. 5. Improved error correction model for RBF network

Fig. 6. Comparison of RBF training processes before and after improvement

Fig. 7. Aperture structure of inner wall of optical darkroom

Fig. 8. Simulation model of distributed photometric measurement platform. (a) Infinite space; (b) general photometric measurement system; (c) photometric measurement system with triple aperture denoising structure

Fig. 9. Comparison of theoretical and measured values of luminous intensity

Fig. 10. Analysis charts of correction results of RBF network. (a) Outputs of photometric data before and after correction; (b) distributions of errors before and after correction