This category covers multi-occultation triangulation, BSF’s method for bubble detection. Unlike cameras, it doesn’t rely on precision optics to form images. Instead, it constructs a picture mathematically using direct line-of-sight data - no lenses or mirrors involved. Sensors collect binary yes/no information: they either detect a pulse of light or they don’t.
An occultation occurs when one object blocks another from view. In this case, a fuel bubble partially blocks light from a specific optical-fiber emitter. If a sensor on the opposite side misses the pulse, the system registers that absence as a sign of the bubble’s presence. With multiple such events, the bubble’s position can be determined by triangulation.