An “air-data probe” system measures at least one component of freestream velocity by tracking the motion of a laser-induced breakdown (“LIB”) spark created in a freestream flow. Neutral density filters are positioned or deployed so that the brightness of the initial LIB spark doesn't over saturate the LIB sensor system. This allows for more consistent tracking of the LIB spark throughout the duration of the LIB spark, including the later stages where the LIB spark is not nearly as bright as the initial LIB spark, thereby allowing all or substantially all of the light generated by the LIB spark to reach the sensors. This provides for enhanced visibility and more accurate detection of the LIB spark over time and as air density changes.