What is multilateration (MLAT) and when is it used in ATC?

What is multilateration (MLAT) and when is it used in ATC?

• A. MLAT uses signals from multiple ground sensors to locate aircraft by triangulation; used where radar coverage is limited or to supplement SSR, especially at airports
• B. MLAT is a satellite navigation system used for oceanic flights
• C. MLAT is a weather radar technology
• D. MLAT triangulates aircraft position using signals from multiple ground sensors to supplement radar coverage

Answer: (D)

Multilateration determines an aircraft’s position by using signals received at multiple ground sensors and comparing the arrival times of the transponder replies. The differences in arrival times across the sensor network allow the system to calculate the aircraft’s location without relying on radar alone. This technique is particularly valuable where traditional radar coverage is incomplete or when extra surveillance is needed to complement SSR data, helping to extend or enhance airspace surveillance. The statement that best fits this concept describes using signals from multiple ground sensors to triangulate the aircraft’s position and to supplement radar coverage. It correctly captures both the method (ground-based sensor network) and the purpose (enhancing surveillance where radar coverage is limited). The other options mischaracterize MLAT as a satellite navigation system or a weather radar technology, and one option uses “triangulation” in a way that implies a different measurement approach and limits its applicability.

Multilateration determines an aircraft’s position by using signals received at multiple ground sensors and comparing the arrival times of the transponder replies. The differences in arrival times across the sensor network allow the system to calculate the aircraft’s location without relying on radar alone. This technique is particularly valuable where traditional radar coverage is incomplete or when extra surveillance is needed to complement SSR data, helping to extend or enhance airspace surveillance.

The statement that best fits this concept describes using signals from multiple ground sensors to triangulate the aircraft’s position and to supplement radar coverage. It correctly captures both the method (ground-based sensor network) and the purpose (enhancing surveillance where radar coverage is limited). The other options mischaracterize MLAT as a satellite navigation system or a weather radar technology, and one option uses “triangulation” in a way that implies a different measurement approach and limits its applicability.