JO 7110.65 3-6-1

The operational status of ASDE systems must be determined during the relief briefing, or as soon as possible after assuming responsibility for the associated position.

Use ASDE systems to augment visual observation of aircraft landing or departing, and aircraftor vehicular movements on runways and taxiways, or other parts of the movement area. ASDE systems with safety logic must be operated continuously.

ASDE systems without safety logic must be operated: Continuously between sunset and sunrise.

When visibility is less than the most distant point in the active movement area, or

When, in your judgment, its use will assist you in the performance of your duties at any time. NOTE-

Radar‐only mode is an enhancement of the ASDE-X and ASSC systems that allows the system to stay operational with safety logic processing during a simultaneous loss of the Multilateration (MLAT) subsystem and ADS-B data or loss of ADS-B data when MLAT is not present. The system stays in full core alert status under radar‐only mode but without automatic data block capability.