How does the system know a vehicle is there?
A sensor in or beside the pavement detects a vehicle at a holding position and reports it to the detection unit, the ALCMS and the tower.
A vehicle detection sensor detects whether a vehicle is present at a point on the airfield, such as a holding position or a road crossing. It may be an inductive loop in the pavement, a magnetometer, radar or a camera. The sensor reports present or not present to a detection unit, which turns the signal into a status.
The status goes to the ALCMS and the tower display. Where the airport has them, the ALCMS can use it with stop bar logic: a sensor before the stop bar shows that a vehicle is waiting, and a sensor beyond it shows that the vehicle has crossed, so the stop bar can be set back to red. A sensor fault must show on the tower display and not give a false clear. Vehicle detection is a source of data, while runway occupancy sensing is the logic that turns data into free or occupied by zone.
Frequently Asked Questions
Q1What is a vehicle detection sensor?
A device that detects whether a vehicle is present at a point on the airfield, such as a holding position or a crossing, and reports it as present or not present.
Q2How does it detect a vehicle?
An inductive loop is a wire loop in the pavement that senses the metal of a vehicle. A magnetometer senses the change in the magnetic field, radar detects position and movement, and a camera uses video analysis. The choice depends on the site.
Q3Where is vehicle detection used?
At holding positions, near stop bars, at taxiway or road crossings of a runway, and anywhere else the system needs to know a vehicle is present.
Q4How does it connect to the AGL system?
A detection unit turns the sensor signal into a status and sends it to the ALCMS and the tower display. Where fitted, the ALCMS uses it with stop bar logic. A sensor fault must show on the tower display and not give a false clear.
Q5Is it the same as runway occupancy sensing?
No. A vehicle detection sensor is a source of data. Runway occupancy sensing is the logic that reports each runway zone as free or occupied and acts on it, and vehicle detectors can be among the sensors that feed it.
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