RVR

RVR (Runway Visual Range) is the horizontal distance a pilot can see down the runway from the approach end, measured by instruments (transmissometers) at specific locations. RVR is reported in meters or feet and is the primary visibility reference for low-visibility approach and landing operations.

RVR is measured at three points: touchdown zone, mid-point, and rollout. Values are included in METAR reports when visibility drops below 2,000 meters (or 6,000 ft). Different ILS categories have specific RVR minimums.