Calculation of Illumination and Uniformity in Baseball Stadium，Baseball Stadium lighting
1. Calculation of illuminance and uniformity of internal and external fields
The lighting of the baseball field is different from the lighting requirements of other stadiums. The area of the baseball field is about 1.6 times that of the football field. The shape of the baseball field is fan-shaped. The illuminance value of the infield and the outfield are very different. Generally speaking, the average illuminance of the infield is higher. The average illuminance in the external field is about 50%, so the uniformity of the external field illuminance is the difficulty, that is, the illuminance value at the junction of the internal field and the external field must be considered. It is hoped that the illuminance values of the inner field and the outer field should be designed to have a significant difference, and it is more hoped that the boundary between the inner field and the outer field will be the watershed of the illuminance value, so as to reduce the illuminance value of the outer field area adjacent to the inner field and reduce the area. The difference between the illuminance value of the arc-shaped edge area of the outer field and the outer field is used to improve the uniformity of the outer field illuminance. In the design, the projection point and beam angle of each lamp must be selected and calculated one by one. If necessary, the height of the light pole must be adjusted to ensure that the various lighting indicators of the baseball field meet the standards of the International Commission of Illumination (CIE) And the relevant standards of domestic venues.
The lighting design of the baseball stadium not only needs to meet the average vertical illuminance and the average horizontal illuminance, but also must achieve the uniformity of the vertical illuminance and the proportional coefficient of the horizontal illuminance. In addition, it is necessary to limit the value of the glare index, and choose a light source with a higher color rendering index and corresponding color temperature, so as to achieve the basic functional requirements of lighting a baseball field. Ensure that baseball players perform their normal skills during night training and games, while ensuring that the color TV broadcast clearly reflects the players' instantaneous movements, movements and sports postures, and can capture the baseball trajectory in high-speed sports.
2. Projection point determination and glare limitation
The limitation of glare can be achieved from many factors such as the determination of the projection point, the adjustment of the height of the lamp pole, and the selection of the beam angle of the lamp. The four-bar light rackets on the curved line of the baseball field all face the home base point of the infield, so determining the illuminance value in the vertical direction can easily cause glare to the receiver. Therefore, to limit the glare index of the baseball field is a key point in lighting design. It must be the placement of one lamp and one lamp, calculating again and again, and modifying side by side until the calculated value is satisfied.
