Abstract: A method of feeding electric power to an LED (4) in an airfield lighting unit (7). The method comprises the steps of: feeding a constant alternating current (Is) to a rectifier (40), rectifying the alternating current (Is) to a rectified current (Ir), pulse width modulating the rectified current (Ir), charging a capacitor (43) with the pulse width modulated rectified current (Ir), and feeding the LED (4) with power from the capacitor (43).

Abstract: A laser range finder (LRF) is used to identify an aircraft approaching a gate. The LRF is directed at the aircraft, and from the echoes, a profile is derived and compared to known profiles. To distinguish among aircraft with similar profiles, the LRF is directed at a volume in which a feature such as an engine is expected and at another volume in which the engine is not expected. The echoes from the two volumes are used to determine whether the engine is in its expected location. If so, the aircraft is identified as the correct type and is allowed to dock at the gate. Otherwise, the aircraft is stopped. The nose height can be used as yet another identifying criterion.

Abstract: The present invention achieves an accurate and quick centerline identification in a docking guidance system and further a verification of a centerline configuration. Heretofore, it is proposed to scan (S1) an apron in front of a docking stand (16) with a range finder (22) and to register a reflection intensity and position for each scanned point. Then, a centerline (14) is identified (S2) in front of the docking stand (16) by using differences in reflection intensity between the centerline (14) and the apron surface surrounding the centerline (14). Further, at least two centerline definition points (38, 40) are defined (S3) in compliance with the centerline layout.

Abstract: A monitoring and control system controls multiple lights and monitors their operation through two-way communication over power lines. An interface is connected to receive control signals for at least one of the lights from the central computer and to transmit monitoring data concerning the lights to the central computer. The interface communicates over the power lines with light controlling and monitoring devices in the field to transmit the control signals over the power lines to the light controlling and monitoring devices and to receive the monitoring data over the power lines from the light controlling and monitoring devices.

Abstract: A system for detecting, identifying and docking aircraft using laser pulses to obtain a profile of an object in the distance initially scans the area in front of the gate until it locates and identifies an object. Once the identity of the object is known, the system tracks the object. The system also monitors an area of the apron near the object to detect obstacles such as ground service vehicles. The system also analyzes the laser pulses to determine whether they are reflected from a solid object or from fog or other condensation or precipitation to avoid misidentifying condensation or precipitation as a solid object.

Abstract: A Method and an arrangement providing detection of deteriorated lamp filaments (3) in a lamp circuit (11) fed by constant current, in particular for a lamp supervision system for airfield lights. A change in a constant current fed through a lamp circuit (11) is initiated, whereby the lamp filament resistance is determined once in conjunction with the change in current and once a time period later. A difference between the resistance determinations constitutes the deterioration of a lamp filament (3) in comparison with a threshold value. Hence, no record of previous resistance determinations have to be stored, and lamps (4) can be replaced when the difference matches the threshold value.

Abstract: A laser range finder (LRF) is used to identify an aircraft approaching a gate. The LRF is directed at the aircraft, and from the echoes, a profile is derived and compared to known profiles. To distinguish among aircraft with similar profiles, the LRF is directed at a volume in which a feature such as an engine is expected and at another volume in which the engine is not expected. The echoes from the two volumes are used to determine whether the engine is in its expected location. If so, the aircraft is identified as the correct type and is allowed to dock at the gate. Otherwise, the aircraft is stopped. The nose height can be used as yet another identifying criterion.

Abstract: A laser range finder (LRF) is used to identify an aircraft approaching a gate. The LRF is directed at the aircraft, and from the echoes, a profile is derived and compared to known profiles. To distinguish among aircraft with similar profiles, the LRF is directed at a volume in which a feature such as an engine is expected and at another volume in which the engine is not expected. The echoes from the two volumes are used to determine whether the engine is in its expected location. If so, the aircraft is identified as the correct type and is allowed to dock at the gate. Otherwise, the aircraft is stopped. The nose height can be used as yet another identifying criterion.