# Virtual Laboratory for the Full-Field Goniophotometer of Luminaires
## 3 System Design Process
### Selection of Measurement Results  
Full-Field Goniopphotometer not only measures the light intensity distribution, but also, with an imaging luminometer or a fast spectroradiometer, the luminance distribution and spectral distribution can be measured separately. When the full spatial distribution photometer is combined with an imaging luminometer, the spatial luminance distribution of a light source or luminaire is measured. The spatial luminance distribution test mainly tests the luminance of the light source or luminaire in space, the flashing area of the road luminaire, and other parameters in order to analyse the spatial luminance distribution of the light source or luminaire. The full spatial distribution photometer is used in conjunction with a fast spectroradiometer to measure the colour distribution and colour directional characteristics of light sources. The accuracy of the measurement of light colour parameters plays a vital role in the quality control of the photovoltaic industry and is also relevant to everyday life.  
When manipulating the virtual experimenter to the full-field goniophotometer, the user completes the electrical connection and luminaire connection, clicks on the measurement selection button to bring up the measurement result selection button, and clicks on the button to bring up three buttons for spectral, luminance, and light intensity distribution, as shown in Figure 6a. The user adds listeners to each of the three buttons, and when clicked, it obtains the text of the clicked button and assigns it to the measurement result selection button, replacing its text. The user clicks on the light intensity distribution button as shown in Figure 6b, clicks on the brightness button as shown in Figure 6c, and clicks on the spectrum button, as shown in Figure 6d.  
At the test results display of the experimental platform, the IES file is imported into TracePro to obtain the illuminance map and light intensity distribution map. Thus display results of the distribution photometer output are achieved through the material switching technique. Manipulating the virtual experimenter to the measurement results display, the illuminance distribution, and light intensity distribution buttons pop up after colliding with the touch block. Clicking on the illuminance measurement directly obtains the illuminance map through material switching while clicking on the light intensity distribution triggers a button event that pops up the right-angle coordinate light intensity distribution and polar coordinate light intensity distribution buttons, and by clicking on the buttons, obtains the right-angle coordinate and polar coordinate light intensity maps, respectively, as shown in Figure 7.  
Figure 6: Switching of test results: (**a**) Interface for switching test results, (**b**) Switching to an interface for light intensity distribution, (**c**) Switching to the brightness screen, (**d**) Switching to the Spectrum interface.  
When a full-field goniophotometer is combined with an imaging luminometer, the luminosity of a luminaire can be measured. Driven by a rotary axis, the imaging luminometer rotates around the LED under the test and measures the luminance distribution of the LED under the test in all directions on the sphere surrounding the light source under the test. The full spatial distribution luminometer is paired with a fast spectroradiometer to measure the spectral distribution of the luminaire. The luminance and spectral results are plotted in the virtual simulation experiment platform as shown in Figure 8.  
Figure 8: Virtual measurement results: (**a**) Resulting graph of luminance distribution, (**b**) Graph showing the spectrum.  
Figure 7: Results of light intensity distribution measurements: (**a**) Diagram of the results showcase, (**b**) Diagram showing illumination, (**c**) Graph showing polar co-ordinate light distribution curves, (**d**) Graph showing right-angle co-ordinate light distribution curves.