Final answer:
The Cat I ILS criteria include a minimum decision height of 200 feet and a minimum runway visual range of 550 meters. It provides lateral and vertical guidance for precise landing approaches.
Step-by-step explanation:
The criteria for a Category I (Cat I) Instrument Landing System (ILS) is defined by specific standards separated into different aspects such as visibility and decision height. A Cat I ILS is the most basic level of ILS and is designed to assist pilots in landing under low-visibility conditions, generally providing guidance down to a minimum decision height of 200 feet (60 meters). Besides decision height, pilots must also have a minimum runway visual range (RVR) of 550 meters, which is the distance over which a pilot of an aircraft on the center line of a runway can see the runway surface markings or the lights delineating the runway or identifying its center line.
The ILS system provides both lateral guidance (localizer) and vertical guidance (glide slope) to pilots. The localizer provides data to ensure the aircraft stays on the centerline of the runway, while the glide slope helps maintain the correct descent profile. The Cat I ILS requires aircraft to be equipped with suitable receivers to interpret the signals transmitted by the ILS ground station. These requirements define the standard for Category I precision instrument approaches, which help pilots land safely in challenging weather conditions.