ASDE-X
The Airport Surface Detection Equipment - Model X (ASDE-X) is an air traffic control radar system developed under a U.S. Federal Aviation Administration program to enhance airport surface surveillance. The system integrates data from multiple sensors, including an X-band Surface Movement Radar (SMR) operating at a pulse repetition frequency of 4 kHz, with pulsewidths of 1 and 100 µs, a peak power of 60 W, a beamwidth of 0.4°, and an antenna rotation of 60 min⁻¹. This fusion of data enables ASDE-X to precisely determine the position and identification of aircraft and transponder-equipped vehicles on the airport movement area, as well as aircraft within a five-mile radius of the airport, providing identification and conflict alerting to air traffic controllers. The first ASDE-X system was deployed in October 2003 at General Mitchell International Airport in Milwaukee, Wisconsin, with plans for installation at 35 U.S. airports.
radartutorial.eu: https://www.radartutorial.eu/19.kartei/03.atc/karte054.en.html