High altitude platform deployment system

• US 20040092258A1
• Filed: 04/17/2003
• Published: 05/13/2004
• Est. Priority Date: 04/17/2002
• Status: Active Grant

• Current Assignee: Aerovironment
• Original Assignee: Aerovironment
• Inventors: Hibbs, Bart D., Cox, Earl C.
• Granted Patent: US 7,555,297 B2
• Time in Patent Office: Days
• US Class Current: 455/431
• CPC Class Codes: H04B 7/18504 Aircraft used as relay or high altitude atmospheric platform

Abstract

A communication system for supporting communications with a target market area. The system includes one or more solar-powered aircraft maintained in, or successively passing through, flight stations or flight patterns around the market area. Each of the aircraft targets limited beamwidth communication antennas on a substantial portion of the target market area. The control system is configured to fly selective flight patterns depending on the aircraft characteristics and the flight conditions. The flight patterns may emphasize high-power-generation patterns such as flying away from the sun for aircraft with wing-mounted solar cells.

Claims

1. A method of establishing a communication system for a target market area, comprising:

stationing each of a plurality of aircraft in separate flight stations of a plurality of flight stations around the target market area, wherein each aircraft has one or more communication system antennas configured with a limited beamwidth;

while each aircraft of the plurality of aircraft is in its flight station, targeting the one or more communication system antennas of that aircraft such that they support communication signals with a substantial portion of the target market area; and

while the communication system antennas of each aircraft support communication signals with a substantial portion of the target market area, controlling flight controls of that aircraft such that the aircraft could be indefinitely maintained within its flight station.

2. The method of claim 1, wherein in the step of controlling, the flight controls of each aircraft of the plurality of aircraft are controlled to maintain the aircraft within its flight station such that the communication system antennas of the aircraft support communication signals with a substantial portion of the target market area for a plurality of days.

3. The method of claim 1, wherein the step of controlling flight controls of each aircraft comprises:

flying the aircraft directly into the wind while wind speeds are above a minimum in-place-loiter wind speed;

flying the aircraft into the wind in a zigzag pattern while wind speeds are above a minimum zigzag wind speed and below the minimum in-place-loiter wind speed; and

flying the aircraft with a repeatedly turning pattern while wind speeds are below the minimum zigzag wind speed.

4. The method of claim 3, wherein each aircraft is configured with an automatic control system configured to control the flight controls based upon the aircraft position and the wind speed during the step of controlling.

5. The method of claim 1, and further comprising:

stationing each of a second plurality of aircraft in the flight stations, wherein each aircraft of the second plurality of aircraft has one or more communication system antennas configured with a limited beamwidth;

while each aircraft of the second plurality of aircraft is in its flight station, targeting the one or more communication system antennas of that aircraft such that they support communication signals with a substantial portion of the target market area; and

while the communication system antennas of each aircraft of the second plurality of aircraft support communication signals with a substantial portion of the target market area, controlling flight controls of that aircraft such that the aircraft could be indefinitely maintained within its flight station;

wherein at each flight station, each aircraft stationed at that flight station alternately supports communication signals with a substantial portion of the target market area such that communications signals are continuously supported throughout a plurality of days.

6. The method of claim 5, and further comprising controlling the flight controls of the first and second pluralities of aircraft such that each aircraft flies a high-power-generation pattern during a portion of the daylight hours of each day of the plurality of days.

7. The method of claim 6, wherein the high-power-generation pattern is a fly-from-sun pattern.

8. The method of claim 6, wherein while the communication system antennas of each aircraft of the first and second pluralities of aircraft support communication signals with a substantial portion of the target market area, the step of controlling flight controls of that aircraft comprises:

flying the aircraft directly into the wind while wind speeds are above a minimum in-place-loiter wind speed;

flying the aircraft into the wind in a zigzag pattern while wind speeds are above a minimum zigzag wind speed and below the minimum in-place-loiter wind speed; and

flying the aircraft with a repeatedly turning pattern while wind speeds are below the minimum zigzag wind speed.

9. The method of claim 6, wherein in the step of stationing each of a second plurality of aircraft, at least two aircraft of the second plurality of aircraft are stationed at each flight station.

10. The method of claim 1, and further comprising stationing an aircraft of the plurality of aircraft in an additional, separate flight station characterized by an angle of elevation of no more than 45 degrees with respect to the target market area.

11. The method of claim 10, wherein the additional, separate flight station is characterized by an angle of elevation of no more than 20 degrees with respect to the target market area.

12. A communication system for a target market area, comprising a plurality of aircraft, each of which is for use in separate flight stations of a plurality of flight stations around the target market area, each aircraft including:

one or more communication system antennas configured with a limited beamwidth, and further configured to support communication signals with a substantial portion of the target market area while the aircraft is in its flight station; and

a control system configured to control flight controls of that aircraft such that the aircraft could be indefinitely maintained within its station while the communication system antennas of each aircraft support communication signals with a substantial portion of the target market area.

13. The communication system of claim 12, wherein the control system of each aircraft is further configured to maintain the aircraft within its station such that the communication system antennas of the aircraft support communication signals with a substantial portion of the target market area for a plurality of days.

14. The communication system of claim 12, wherein the control system of each aircraft is further configured to control its flight controls such that the aircraft flies:

directly into the wind while wind speeds are above a minimum in-place-loiter wind speed;

into the wind in a zigzag pattern while wind speeds are above a minimum zigzag wind speed and below the minimum in-place-loiter wind speed; and

in a repeatedly turning pattern while wind speeds are below the minimum zigzag wind speed.

15. The communication system of claim 12, wherein the control system is further configured such that at least two aircraft are stationed at each flight station, and wherein at each flight station, each aircraft stationed at that flight station alternately supports communication signals with a substantial portion of the target market area such that communications signals are continuously supported throughout a plurality of days.

16. The communication system of claim 15, wherein the control system is further configured such that at each flight station, each aircraft stationed at that flight station flies a high-power-generation pattern during a portion of the daylight hours of each day of the plurality of days.

17. The communication system of claim 16, wherein the high-power-generation pattern is a fly-from-sun pattern.

18. The communication system of claim 16, wherein the control system of each aircraft is further configured to control its flight controls, while the communication system antennas of each aircraft support communication signals with a substantial portion of the target market area, such that the aircraft flies:

directly into the wind while wind speeds are above a minimum in-place-loiter wind speed;

into the wind in a zigzag pattern while wind speeds are above a minimum zigzag wind speed and below the minimum in-place-loiter wind speed; and

in a repeatedly turning pattern for wind speeds below the minimum zigzag wind speed.

19. A communication system for a target market area, comprising a first aircraft and a second aircraft for use in a flight station around the target market area, each aircraft including:

one or more communication system antennas configured with a limited beamwidth, and further configured to support communication signals with a substantial portion of the target market area while the aircraft is in the flight station; and

a control system configured to maintain the aircraft within the station during a portion of each day of flight, and to fly a high-power-generation pattern outside of the station during a portion of the daylight hours of each day of flight, wherein the control system is further configured to control flight controls of the aircraft such that the aircraft could be indefinitely maintained within the station while the aircraft is being maintained within the station;

wherein the control system is further configured to coordinate with the control system of the other aircraft such that at least one aircraft is maintained within the station at all times during each day of flight.

20. The communication system of claim 19, wherein either the first or the second aircraft is maintained in the station at all times during each day of flight.

21. The communication system of claim 19, wherein the high-power-generation pattern is a fly-from-sun pattern.

22. A communication system for a target market area, comprising:

a solar powered aircraft configured to continuously fly a high-power-generation pattern, the aircraft including one or more communication system antennas with a limited beamwidth, the antennas being configured to support communication signals with a plurality of ground antennas in a substantial portion of the target market area; and

a ground antenna in the target market area configured to track the aircraft, and further configured to support communication signals with the antennas of the aircraft.

23. The communication system of claim 22, and further comprising a second solar powered aircraft configured to continuously fly a high-power-generation pattern that is offset from the pattern of the first aircraft, the second aircraft including one or more communication system antennas with a limited beamwidth, the antennas being configured to support communication signals with the plurality of ground antennas

wherein the ground antenna is configured to track the second aircraft, and further configured to support communication signals with the antennas of the second aircraft;

and

wherein the ground antenna is configured to selectively communicate with whichever aircraft is best positioned for communications with the ground antenna.

24. A communication system for a target market area having a designated flight station, comprising a plurality of aircraft, each of which is for use in separate flight patterns of a plurality of flight patterns located around the target market area and passing through the flight station, each aircraft including:

one or more communication system antennas configured with a limited beamwidth, and further configured to support communication signals with a substantial portion of the target market area while the aircraft is passing through the flight station; and

a control system configured to control flight controls of that aircraft such that the aircraft flies a high-power-generation flight pattern, wherein the control system is configured to coordinate with the control systems of the other aircraft to assure that each aircraft'"'"'s departure form the flight station is slightly preceded by another aircraft'"'"'s arrival in the flight station.

25. The communication system of claim 24, wherein the high-power-generation flight pattern is a fly-from-sun flight pattern.

26. A communication system for a target market area, comprising:

an aircraft configured with one or more communication system antennas and a control system;

wherein the one or more communication system antennas are configured with a limited beamwidth, and are further configured to support communication signals with a substantial portion of the target market area; and

wherein the control system is configured to control flight controls of that aircraft such that the aircraft flies a high-power-generation flight pattern positioned to maximize the antennas communication with the target market area.