2.2. | "Retro-reflection " means the reflection in which light is reflected in directions close to the direction from which it came. This property is maintained over wide variations of the illumination angle. | a0c0 |
2.2. | "Retro-reflection " means the reflection in which light is reflected in directions close to the direction from which it came. This property is maintained over wide variations of the illumination angle. | a0c0 |