Abstract: The marker has a pair of upwardly converging reflectant planar panels facing approximately in opposite directions. In its correct attitude on a support surface the panels slope at 2.degree.-6.degree. to the vertical if the marker is intended for assisting the landing of fixed wing aircraft and at 8.degree.-10.degree. to the vertical if the marker is intended for assisting the landing of helicopters (Collectively at 2.degree.-10.degree. to the vertical). The reflectant panels are preferably retroreflectant. Preferably the opposed sloping panels converge when considered relative to intersecting horizontal planes (when the marker is properly levelled). This convergence may also be measured as the angle between vertical planes respectively perpendicular to the opposed panels. Such convergence in plan may preferably be 0.degree.-6.degree. for use with fixed wing aircraft but may be larger for fixed wing aircraft in certain conditions. Such convergence in plan is preferably 16.degree.-20.degree.

Abstract: In an arrangement for supervising and controlling field light units (20) at an airport, a regulator provided with a monitoring unit for power supply and for monitoring the light units is arranged individually for each light unit (18,20) to regulate the light intensity of the light units and to receive information as to their operational status. In a preferred embodiment, each light unit comprises two separate light sources that can be alternately and separately connected into circuit in case of failure to either of the light sources. Each light unit is provided with an electronic unit including a regulator, monitoring unit, and modem for power supply to the light unit and for monitoring the operation of the light unit. Each light unit is individually addressable from a control central for the airport. A ground traffic control system can be integrated into the field lighting system by connecting suitable presence detectors to the system.

Abstract: A runway marker has a pair of upwardly converging reflectant planar panels facing approximately in opposite directions. In its correct attitude on a support surface the panels slope at 2.degree.-6.degree. to the vertical if the marker is intended for assisting the landing of fixed wing aircraft and at 8.degree.-10.degree. to the vertical if the marker is intended for assisting the landing of helicopters. The reflectant panels are preferably retroreflectant.

Abstract: An aircraft landing system is disclosed in which a differential GPS global positioning system is employed. A ground station, located in the vicinity of one or more landing strips, includes a GPS receiver and a data link transmitter for transmitting GPS correction data and also the global position of two points which define a desired aircraft glide path associated with a particular landing strip. The system further includes aircraft equipment comprising a receiver for receiving the correction data and the global position of the two glide path points, and a GPS receiver. The aircraft equipment further includes a computer for determining a corrected global position of the aircraft as a function of the aircraft GPS range data and the correction data, and subsequently determines the lateral deviation and vertical deviation from the glide path defined by the two glide path points.

Abstract: A microwave locating system is provided for locating known features and distinguishing between different types of features. The locating system includes a plurality of modulated microwave power sources located on known features and radiating modulated microwave signals having modulated frequencies selected in accordance with the known features. A video detection sensor camera is located remote from the sources for sensing microwave signals within a field of view and providing location signals for each of the sources. The camera includes an array of receiver elements which provide narrow bandwidth filtering so as to identify received signals as one of a plurality of selected modulated frequencies. The locating system further provides an image of the location signals which distinguishes between different selected located features.

Abstract: A remote area landing system combines retro reflective markers with a lighting system. The markers reflect light from a landing aircraft or helicopter. The preferred marker is aluminum with a polycarbonate cover layer. The lights are solar powered and are radio controlled from the aircraft.

Abstract: In an arrangement for supervising and controlling field light units (20) at an airport, a regulator provided with a monitoring unit for power supply and for monitoring the light units is arranged individually for each light unit (18,20) to regulate the light intensity of the light units and to receive information as to their operational status. In a preferred embodiment, each light unit comprises two separate light sources that can be alternately and separately connected into circuit in case of failure to either of the light sources. Each light unit is provided with an electronic unit including a regulator, monitoring unit, and modem for power supply to the light unit and for monitoring the operation of the light unit. Each light unit is individually addressable from a control central for the airport. A ground traffic control system can be integrated into the field lighting system by connecting suitable presence detectors to the system.

Abstract: A beacon device for alerting friendly personnel on land, sea or air, from close proximity up to several miles, that the beacon location is also friendly, is contained in an upright case that has an least one infra-red (IR) light emitting diode and a visible light emitting diode clustered together at the top of the case, from which overlapping IR and visible light beacons emanate upward when the case is upright and means including one or more switches on the device or remote from the device are provided for controlling electric power to the diodes. In a preferred embodiment an adjustable collar surrounding the clustered diodes is moveably attached to the case and is moveable downward on the case to intercept less of the overlapping beacon light so that the elevation angle (.theta.) of the beacon is relatively low and is moveable upward on the case to intercept more of the overlapping beacon light so that the elevation angle (.theta.) of the beacon is relatively high.

Abstract: Disclosed is an improvement to Integral Monitoring of two-frequency Instrument Landing System Localizer transmitting antenna arrays, by means of which the Clearance signal can be precisely separated from the combined Course and Clearance output of an Integral Monitor recombiner and monitored as if it existed alone. A first detector detects a composite Clearance and Course signal input, and sends an output to a separation filter which does not pass frequencies of 0, 90 or 150 hertz, but does pass frequencies of the difference between Course and Clearance frequencies (.DELTA.f), .DELTA.f.+-.90 hertz, and .DELTA.f.+-.150 hertz. The output of the filter is input to a second detector which measures the difference between the percentages of 90 and 150 hertz amplitude modulations of an amplitude modulated carrier having a frequency .DELTA.f.

Abstract: A disc arrangement is provided for positioning about airport lights for inhibiting erosion and suppressing foliage.

Abstract: Optical guidance system for the night landing of aircraft on a landing area along a determined approach path, which comprises two horizon reference luminous bars (1, 2) disposed in alignment with each other in a horizontal direction substantially perpendicular to the approach path, and two azimuth overshoot indicating lamps, respectively to the left (5) and to the right (6), located at the outer ends of the pair of horizon reference bars and provided with masks (8) in order that they can only be seen by the aircraft if the latter overshoots the approach path in azimuth to the left and to the right respectively.

Abstract: An improved runway lighting system comprises a first set of runway lights providing illumination in one direction along the runway, a second set of runway lights providing illumination in the opposite direction along the runway and a switching unit for switching on either the first set of lights or the second set of lights, depending on the direction of approach of incoming aircraft. A control unit provides current pulses along existing runway circuitry to operate the switching unit. Circuitry in the switching unit determines which set of lights to illuminate based upon the amplitude and duration of the current pulse. A selector switch may also be provided in the control tower to remotely operate the control unit.

Abstract: The landing approach aid for aircraft exhibits, on the one hand, triple mors (4,6) on the landing field. On the other hand, the aircraft (1) is provided with a spotlight, a television camera in the vicinity of the spotlight (at 3) and a device for displaying and/or evaluating the recorded television images. (FIG. 1).

Abstract: Navigation by interpretation of images of parallelogram corner points of a ground beacon array. A video camera senses images of the beacon array and a computer interprets the images to provide attitude and location of the platform, on which the camera is mounted, relative to the array.

Abstract: The fault monitoring function of an executive monitor contained in a microwave landing system is verified by evaluating a history of the parametric information sampled by an executive monitor and storing in memory the number of out of tolerance parametric signals received from an antenna means over a predetermined time period, replacing the stored number of out-of-tolerance parametric signals with a predetermined number that will be beyond a second predetermined limit if another out-of-tolerance parametric signal is added to said number, adding one such internally generated out-of-tolerance parametric signal to said predetermined number, generating an alarm if said sum is beyond the second predetermined limit, and restoring the previously stored number of out-of-tolerance parametric signals received from the antenna means if the alarm was generated, and shutting the system down if an alarm was not generated.

Abstract: An improved glide slope indicator system for facilitating aircraft landings under adverse lighting conditions on remote or austere landing sites is provided which comprises a pair of indicators deployable near ground level on each side of a runway, each indicator including a housing having an optical window and a pair of light sources mounted in predetermined spaced relationship to each other and to the optical window and connected to a power source and related circuitry to project a well defined first blinking and second steady light beam of predetermined angular divergence and overlap, one indicator disposed to project beams with an overlap elevated at a first angle relative to horizontal and the other indicator disposed to project beams with an overlap elevated at a second angle relative to horizontal different from the first, with a preselected glide path lying between the two overlaps.

Abstract: A system to provide warning whenever unreliable data is being received by an airborne receiver for a microwave landing system. The received data is tested against certain criteria to determine validity. The received data is also tested to determine whether it was received via a direct path or via a multipath reflection. A validity counter records the percentage of valid data received. A multipath counter records the length of time data is received via direct path relative to the length of time data is received via multipath. Both counters control warning flags to cause a warning to be generated whenever the counter contents are below threshold values. The validity counter is set to an upper limit when its count crosses the threshold in a positive direction and is set to a negative limit when its count crosses the threshold in a negative direction.

Abstract: A remotely-controlled lighting system for austere landing zone lighting includes a plurality of light units each having dual electroluminescent light panels, a plurality of remote controllers each having an electrical receiver, and a separate electrical transmitter. The light panel units and remote controllers, attached electrically, may also be attached physically and placed along the sides of a landing zone, while the separate transmitter is located at a remote, covert place, such as a foxhole. The transmitter and receivers of the remote controllers are capable of being preset to respectively transmit and receive a first sequence of coded pulses for turning "on" the light panel units and a second sequence of coded pulses different from the first sequence for turning "off" the light units.

Abstract: A diffuse incandescent runway marker light apparatus has a housing with a visible light diffusing plate mounted in one end and an infrared light diffusing plate mounted in the other end, and a pair of incandescent light sources mounted in the housing and aimed toward the respective housing end plates. A switch, when flipped to a first position, turns on one light source for producing visible illumination and turns off the other light source. The switch, when flipped to a second position, turns off the one light source and turns on the other light source for producing infrared illumination. In such manner, the appropriate type of illumination for marking the runway for overt or covert landing operation may be selected. When the switch is flipped to a third position, both light sources are turned off.

Abstract: Unattended measurements of horizontal and vertical visibility are broadcast, along with the results of time trend analysis so as to provide for short-term prediction of visibility. A calibration mechanism is provided along with sensors to determine mis-alignment of the apparatus. Broadcast information is particularly useful to pilots approaching unattended airports for landing.