Most likely the detectors/emitters are in a diagonal crosshatch pattern, which would also greatly simplify detection and resolution on the axis perpendicular to

Most likely the detectors/emitters are in a diagonal crosshatch pattern, which would also greatly simplify detection and resolution on the axis perpendicular to the air bar: /\/\/\/\/\/\/\/\/\/\ \/\/\/\/\/\/\/\/\/\/ /\/\/\/\/\/\/\/\/\/\ --------------------