Abstract: Through the study of the principle of floodlighting, the index of floodlighting, the characteristics of lamps, the performance of light sources, etc., how to better apply floodlighting in urban night scenes. Third, the design method
Keywords: light source floodlighting local illumination city night scene 
I) Guiding Thoughts In order for floodlighting to meet the requirements of illumination and uniformity, the design process usually involves three steps:
1. A more practical assessment includes the location of the floodlight, the type of light distribution required, and the characteristics of the light source for this particular application.
2. Calculate the number and load of the lamps using the lumen method according to the illuminance indicator.
3. If necessary, to determine the aiming pattern of the floodlight, use the point-by-point method to calculate the required uniformity.
The third step may make the necessary corrections to the preliminary calculations, where computers are typically used for calculations, especially for large and complex sites. Most decorative floodlight designs are designed with the first two steps, and then their success depends on the combination of aesthetic appreciation, experience, intuition and sixth sense.
2) Illumination calculation method 1. Lumens calculation method Σ φ = AE / η where: Σ φ - - the luminous flux required to project all onto the façade, lm;
A—the total area of ​​the illuminated facade, m2;
E———the selected illuminance value, lx;
η———Using the coefficient, 0. 25～0. 35.
2, luminous intensity method calculation formula P = ED2 or P = EL2 / sin (a) 3 cos (a) where: P - the luminous intensity required for the building facade, cd;
D—the distance of the floodlight from the building, m;
L———the height of the floodlight projection, m;
E———the vertical illumination required on the facade, lx;
a——— the angle between the direction in which the light source is projected and the ground plane.