Which illumination pattern is fired perpendicular to the observer target line?

The illumination pattern that is fired perpendicular to the observer target line is the Two Gun Illumination Lateral Spread. This pattern is specifically designed to create an illumination effect that spreads laterally rather than along the range towards the target, which is ideal when the aim is to provide a wide area of illumination across the battlefield or a specific zone without necessarily following the direct line of sight towards the target.

In contrast, the Two Gun Illumination Range Spread primarily focuses on distributing illumination along the range towards the target, making it less effective for scenarios where lateral illumination is required. Multi-Gun Illumination refers to the use of multiple guns but does not specify the directional pattern of illumination, while Two Gun Illumination is a generic term that doesn't clarify the spread direction either. Therefore, the Lateral Spread option accurately identifies the unique characteristic of being perpendicular to the observer target line, fulfilling the specific need for a broad lateral area of light.