System for avoidance of collision between an aircraft and an obstacle

Abstract

A field unit for warning of a danger of collision between an aircraft and an obstacle, in particular a topographical ground obstacle or an obstacle formed by a mast, building or aerial cable structure, comprises a multi-part tubular mast having devices for fixing a solar panel and a radar antenna; an elongate radar antenna in an environment-protective casing, which, with an electronics unit, forms a radar system for synthesized radar detection of an aircraft in a radar coverage area; a central processing unit for identifying on the basis of information from the radar system an aircraft which is in a zone of the radar coverage area and which on the basis of radar information such as direction, distance and/or speed computes a collision danger area; and a high-intensity light system and radio transmitter system that can be activated by the central processing unit upon detection of an aircraft in a collision danger area. The radio transmitter system may be a VHF or UHF radio transmitter system for providing a radio signal modulated by an audible warning signal, preferably a voice warning signal, whilst the light system preferably comprises a stroboscope light system. The field unit is arranged for communication with other similar field units for remote activation of light or audio warnings in a neighbouring field unit.

1. A field unit for warning of a danger of collision between an aircraft and an obstacle, in particular a topographical ground obstacle or an obstacle formed by a mast, building or aerial cable structure, characterised in that it comprises:
 a multi-part tubular mast having a fixing device on one side face for a solar panel and a fixing device at an upper end for a radar antenna;  
 an elongate radar antenna arranged vertically in the longitudinal direction and having a plurality of antenna panels and provided with an environment-protective casing, which radar antenna is in communication with radar electronics to form a radar system for synthesized radar detection of an aircraft in a radar coverage area;  
 a central processing unit in communication with the synthesized radar detection radar system for processing information from the radar system, which information includes at least one indication of direction and several indications of distance or at least one indication of direction, one indication of distance and one indication of speed, and for identifying a radar system detected aircraft that is in a zone of the radar coverage area computed by the central processing unit as a collision danger area on the basis of the information;  
 a high-intensity light system connected to and controlled by the central processing unit for providing a high-intensity light warning signal, the light system being activatable  activated by the central processing unit upon the detection of an aircraft in the collision danger zone;  
 at least one of a VHF orand UHF radio transmitter system connected to and controlled by the central processing unit for providing a radio signal modulated by an audible warning signal, the at least one of the VHF orand UHF radio transmitter system being activatableactivated by the central processing unit upon the detection of an aircraft in the collision danger zone; and  
 an electric power supply system comprising a solar panel secured to a fixing device, a chargeable back-up battery and a power supply control for power supply to the radar system, the central processing unit, the high-intensity light system and the VHF or UHF  radio transmitter system.  
 
     
     
       2. A field unit as disclosed in  claim 1 , further comprising a position transmitting device based on the global positioning system GPS. 
     
     
       3. A field unit as disclosed in  claim 1 , further comprising a communication device connected to the central processing unit and arranged for communication with a similar second field unit, wherein the central processing unit is arranged to transmit to the second field unit information from the local radar system about the detected aircraft, and is arranged to receive from the second field unit information from the second field unit's local radar system about a detected aircraft and, on the basis of the information received, to activate the light system or the VHF or UHF radio transmitter system. 
     
     
       4. A field unit as disclosed in  claim 1 , wherein the detection zone is at least 3000 meters, and wherein a warning zone for the collision danger area is defined as an elongate  area around an associated aerial obstacle extending to a distance from the aerial obstacle that corresponds to a flying time of preferably  approximately 15 seconds, and preferably not less than 4.5 seconds,  on the basis of the aircraft's speed for an aircraft that is within a computed height of less than 50 meters below a defined obstacle height. 
     
     
       5. A field unit as disclosed in  claim 1 , wherein the detection zone is at least 3000 meters, and wherein a warning zone for the collision danger area is defined as a partly spherical  an area around an associated point obstacle extending to a distance from the point obstacle that corresponds preferably  to a flying time of 15 seconds, and preferably not less than  at least 4.5 seconds,  on the basis of the aircraft's speed for an aircraft that is within a computed height of less than 50 meters below a defined obstacle height. 
     
     
       6. A field unit as disclosed in  claim 1 , wherein the light system includes at least one stroboscope light system. 
     
     
       7. A field unit as disclosed in  claim 1 , wherein the audible warning signal is a voice signal that gives information specifying the obstacle. 
     
     
       8. A field unit as disclosed  claim 1 , further comprising a remote monitoring system for at least one of reporting to an operation centre at least one operating state of the field unit, controlling the field unit, and optionally for control or  performing remote maintenance of the field unit. 
     
     
       9. A field unit as disclosed in  claim 1 , wherein the central processing unit is arranged to activate at least one of the light system and/or VHF or UHF  radio transmitter system preferably  approximately 15 seconds before a computed collision time on the basis of the detected aircraft's direction, distance and speed relative to the obstacle. 
     
     
       10. A field unit as disclosed in  claim 1 , wherein the light system is arranged to emit a flashing light with a repetition rate of about 40 flashes per minute. 
     
     
       11. A field unit for warning a target of an obstacle comprising:
   a radar antenna having a plurality of antenna elements, which radar antenna is in communication with radar electronics to form a radar system for synthesized radar detection of a target in a radar coverage area;        a central processing unit in communication with the synthesized radar detection radar system for processing information from the radar system, which information includes at least one indication of direction and several indications of distance or at least one indication of direction, one indication of distance and one indication of speed, and for identifying a target that is within a first and second warning zone of the radar coverage area computed by the central processing unit on the basis of the information;        a light system connected to and controlled by the central processing unit for providing a light warning signal, the light system being activated by the central processing unit upon the detection of the target in the first warning zone;        a radio transmitter system connected to and controlled by the central processing unit for providing a radio frequency audible warning signal, the radio transmitter system being activated by the central processing unit upon the detection of the target in the second warning zone; and        an electric power supply system for providing power supply to the radar system, the central processing unit, the light system and the radio transmitter system.     
     
     
       12. The field unit of  claim 11 , wherein the radio transmitter system is configured to provide the audible warning signal across all frequencies relevant to the target in at least one of the UHF and VHF radio frequency bands. 
     
     
       13. The field unit of  claim 11 , wherein the plurality of antenna elements provide  360  degree radar coverage area in the vicinity of the obstacle. 
     
     
       14. The field unit of  claim 11 , wherein the light system and radio transmitter system are in a sleep mode until activated by the central processor unit. 
     
     
       15. The field unit of  claim 11 , wherein the unit is one of a plurality of field units having coverage areas that are in communication to exchange information about target movements within the coverage areas and operational status information. 
     
     
       16. A method of warning a target of an obstacle comprising:
   providing a field unit capable of detecting and warning a target of an obstacle;        monitoring a coverage area in the vicinity of an obstacle for a target using the field unit;        detecting when the target has entered the coverage area;        determining information about the target including speed, direction, and height of the target;        calculating first and second warning zones based on the information;        providing a first warning to the target, when the target enters the first warning zone;        providing a second warning to the target, when the target enters the second warning zone, wherein the second warning is different than the first warning.     
     
     
       17. The method of  claim 16 , wherein:
   the providing a first warning to the target, includes providing a first warning in the form of at least one visible light in the vicinity of the obstacle; and,        the providing a second warning to the target, includes providing a second warning in the form of audible warning.     
     
     
       18. The method of  claim 16 , wherein:
   the providing a first warning to the target, includes providing a first warning in the form of at least one flashing visible light in the vicinity of the obstacle; and,        the providing a second warning to the target, includes providing a second warning in the form of audible warning in frequencies relevant to the target in at least one of the UHF and VHF radio frequency bands.     
     
     
       19. The method of  claim 16 , further comprising:
   configuring a light system and a radio transmitter to be in a sleep mode;        activating the light system to provide a light signal in the vicinity of the obstacle, when the target enters the first warning zone; and,        activating the radio transmitter to provide an audio signal when the target enters the second warning zone.     
     
     
       20. The method of  claim 16 , further comprising desisting from providing warnings when the target remains inside the warning zone. 
     
     
       21. The method of  claim 16 , further comprising:
   providing at least first and second field units in communication to exchange information about target movements within respective coverage areas and operational status information; and,        exchanging information between the field units relating to the target detected within the coverage areas.     
     
     
       22. A field unit for warning a target of an obstacle comprising:
   a radar antenna having a plurality of antenna elements, which radar antenna is in communication with radar electronics to form a radar system for synthesized radar detection of a target in a radar coverage area;        a central processing unit in communication with the synthesized radar detection radar system for processing information from the radar system, which information includes at least one indication of direction and several indications of distance or at least one indication of direction, one indication of distance and one indication of speed, and for identifying a target that is within at least one warning zone of the radar coverage area computed by the central processing unit on the basis of the information;        a light system connected to and controlled by the central processing unit for providing a light warning signal, the light system being activated by the central processing unit upon the detection of the target in at least one of the warning zones, wherein the light system is in a sleep mode until activated by the central processing unit and desists from providing warnings when the target remains inside the warning zone; and,        an electric power supply system for providing power supply to the radar system, the central processing unit, and the light system.     
     
     
       23. The field unit of  claim 22 , wherein the field unit provides for remote monitoring of the field unit from an operations centre. 
     
     
       24. A method of warning a target of an obstacle comprising:
   providing a field unit capable of detecting and warning a target of an obstacle;        monitoring a coverage area in the vicinity of an obstacle for a target using the field unit;        detecting when the target has entered the coverage area;        determining information about the target including speed, direction, and height of the target;        calculating at least a first warning zone based on the information;        providing a first warning to the target, when the target enters the first warning zone; and,        desisting from providing warnings to the target, when the target remains inside the first warning zone.     
     
     
       25. The method of  claim 24 , further comprising:
   providing at least first and second field units in communication to exchange information about target movements within respective coverage areas and operational status information; and,        exchanging information between the field units relating to the target detected within the coverage areas.