WO2003094287A1 - Procedes d'alignement de faisceaux pour antenne - Google Patents

Procedes d'alignement de faisceaux pour antenne Download PDF

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Publication number
WO2003094287A1
WO2003094287A1 PCT/US2002/013743 US0213743W WO03094287A1 WO 2003094287 A1 WO2003094287 A1 WO 2003094287A1 US 0213743 W US0213743 W US 0213743W WO 03094287 A1 WO03094287 A1 WO 03094287A1
Authority
WO
WIPO (PCT)
Prior art keywords
antenna
transmit
satellite
transmit antenna
receive
Prior art date
Application number
PCT/US2002/013743
Other languages
English (en)
Inventor
Michael De La Chapelle
Christopher Mclain
David S. Parkman
Original Assignee
The Boeing Company
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by The Boeing Company filed Critical The Boeing Company
Priority to AU2002303571A priority Critical patent/AU2002303571A1/en
Priority to PCT/US2002/013743 priority patent/WO2003094287A1/fr
Publication of WO2003094287A1 publication Critical patent/WO2003094287A1/fr

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S3/00—Direction-finders for determining the direction from which infrasonic, sonic, ultrasonic, or electromagnetic waves, or particle emission, not having a directional significance, are being received
    • G01S3/02—Direction-finders for determining the direction from which infrasonic, sonic, ultrasonic, or electromagnetic waves, or particle emission, not having a directional significance, are being received using radio waves
    • G01S3/14—Systems for determining direction or deviation from predetermined direction
    • G01S3/16—Systems for determining direction or deviation from predetermined direction using amplitude comparison of signals derived sequentially from receiving antennas or antenna systems having differently-oriented directivity characteristics or from an antenna system having periodically-varied orientation of directivity characteristic
    • G01S3/20—Systems for determining direction or deviation from predetermined direction using amplitude comparison of signals derived sequentially from receiving antennas or antenna systems having differently-oriented directivity characteristics or from an antenna system having periodically-varied orientation of directivity characteristic derived by sampling signal received by an antenna system having periodically-varied orientation of directivity characteristic
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/12—Supports; Mounting means
    • H01Q1/125—Means for positioning
    • H01Q1/1257—Means for positioning using the received signal strength
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/27—Adaptation for use in or on movable bodies
    • H01Q1/28—Adaptation for use in or on aircraft, missiles, satellites, or balloons
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/14—Relay systems
    • H04B7/15—Active relay systems
    • H04B7/185—Space-based or airborne stations; Stations for satellite systems
    • H04B7/18502—Airborne stations
    • H04B7/18506—Communications with or from aircraft, i.e. aeronautical mobile service
    • H04B7/18508—Communications with or from aircraft, i.e. aeronautical mobile service with satellite system used as relay, i.e. aeronautical mobile satellite service

Definitions

  • the present invention relates to antenna systems for communicating with satellite based transponders, and more particularly to a beam alignment system method for correcting beam misalignment between a transmit antenna and a receive antenna, where both antennas are carried on a mobile platform and aimed at a target satellite transponder.
  • the transmit antenna beam pointing direction is slaved to that of the receive antenna beam to provide two way communication with the satellite, the physical separation between the two antennas can result in beam misalignment of a sufficient magnitude to cause a degradation in system performance.
  • Another major concern is a regulatory based concern that the beam of the transmit antenna does not interfere with other satellites adjacent the target satellite orbiting along a geosynchronous or non-geosynchronous arc.
  • the receive antenna is used to track the target satellite using a variety of well known methods such as dithering, conical scanning, monopulse, etc., and the transmit antenna is simply pointed in the direction of the target satellite as determined by the receive antenna tracking system. This is known as the "slaved" approach.
  • a problem is that there is presently no method to detect and correct for transmit/receive antenna misalignment for remote mobile terminals without removing them from service.
  • the misalignment becomes too large, then it is simple to detect because the transmit antenna will no longer point at the target satellite and the communication uplink to the satellite will no longer function.
  • an alternative method of pointing the transmit antenna is simply using an "open loop" pointing approach, wherein the position and attitude of the mobile platform (gleaned from an on-board navigation system of the mobile platform) and a known position of the target satellite are used to determine the direction of pointing of the transmit antenna.
  • the shortcoming of the open loop pointing approach is that its pointing accuracy is limited by the accuracy of the on-board navigation system.
  • the information provided by the on-board navigation system is typically not quite accurate enough to achieve the needed pointing accuracy of the transmit antenna, which is on the order of about 0.1°.
  • some form of beam alignment system is needed to correct for misalignment of a transmit antenna beam relative to a receive antenna beam when the receive and transmit antennas are used to communicate with an orbiting satellite.
  • Such a system and method is further required which can be implemented without requiring significant additional costly and complex equipment to be carried on a mobile platform, and which can be expected to function with little or no maintenance.
  • the present invention is directed to a system and method for correcting for misalignment between a transmit antenna beam and a receive antenna beam of transmit and receive antennas operating on a host platform and communicating with a satellite communications system. It is anticipated that the present invention will find particular utility in connection with transmit and receive antennas carried on mobile platforms such as aircraft, however, the invention is equally applicable to a stationary host platform or to other forms of mobile platforms such as ships or moving land based vehicles.
  • the present invention determines a beam center of the receive antenna tracking a target satellite through one of a plurality of well known methods. Once the beam center of the receive antenna is determined, the transmit antenna is pointed in accordance with pointing angles determined for the receive antenna, as described above. One of a plurality of well known methods is used to then determine a beam center of the transmit antenna as the transmit antenna transmits information to the target satellite. Sequential lobing is one preferred method which is used to determine the beam center of the transmit antenna. [0008] A parameter of the signal quality or signal strength of the received signal at a ground station in communication with the target satellite is then measured and recorded for each one of a plurality of points in the transmit antenna sequential lobing pattern.
  • the recorded signal strength or quality measurements are then transmitted to the host platform via the target satellite. From this information, the alignment error between the transmit and receive beams can be determined. Alternatively, this information may be used to determine the alignment error between the transmit and receive antennas on the ground. The correction can then be transmitted via the target satellite to the host platform. [0009] It will be appreciated that the system and method of the present invention may be used with virtually any well known method for determining the antenna pointing angles to the target satellite. Sequential lobing is one preferred method. Other well known methods include beam dithering, conical scanning and monopulse tracking.
  • the parameter measured by the receiver of the ground station and fed back to the host platform for finding the beam center of the transmit beam comprises signal strength in one preferred embodiment of the invention, but other possible parameters are signal-to-noise ratio (S/N), carrier-to-noise ratio (C/N) or energy per bit divided by noise spectral density (Eb/No).
  • S/N signal-to-noise ratio
  • C/N carrier-to-noise ratio
  • Eb/No energy per bit divided by noise spectral density
  • Figure 1 is a simplified illustration of a mobile platform having a transmit antenna and a receive antenna in communication with a ground station via a target satellite having at least one radio frequency (RF) transponder, and illustrating the forward and return communications links for implementing the present invention
  • Figure 2 is an illustration of the aircraft in two-way communication with the target satellite during the process of determining the beam centers of the transmit and receive antenna beams
  • Figure 3A illustrates the pattern of beam pointing used as part of the sequential lobing process for the receive antenna to determine the pointing angle in azimuth;
  • Figure 3B illustrates the pattern of beam pointing used as part of the sequential lobing process for the receive antenna to determine the pointing angle in elevation
  • Figure 4 illustrates the azimuth alignment error between the transmit and receive antenna beams determined from the sequential lobing
  • Figure 5 illustrates the elevation alignment error between the transmit and receive antenna beams determined from the sequential lobing process
  • Figure 6 is a flow chart of the steps performed in determining the alignment error between the transmit and receive antenna beams.
  • a system 10 is shown for correcting for beam misalignment between a receive antenna 12 and a transmit antenna 14 on a host platform 16.
  • the antennas 12 and 14 allow the host platform 16, which is shown in this example as a mobile platform, and more particularly as an aircraft, to communicate with a ground station 18 via a transponded satellite 20.
  • the ground station 18 includes a receive antenna 22 in communication with a receiver 24 and a transmit antenna 26 responsive to an output of a transmitter 28.
  • the receiver 24 of the ground station 18 further includes an output 34 which is fed to an input 36 of the transmitter 28 via a feedback loop 38.
  • Feedback loop 38 enables a received signal strength indicator (RSSI) or some other value indicative of signal quality such as energy per bit divided by noise spectral density (Eb/No), signal-to-noise (S/N) or carrier-to-noise (C/N) to be fed back by the receiver 24 to the transmitter 28 to assist in correcting for beam misalignment between the receive and transmit antennas 12 and 14, respectively.
  • RSSI received signal strength indicator
  • Eb/No noise spectral density
  • S/N signal-to-noise
  • C/N carrier-to-noise
  • the system 10 and method of the present invention initially determines the center of the received antenna beam, as denoted by dashed line 36.
  • This can be accomplished by a number of well known methods, but one preferred method is through sequential lobing.
  • Sequential lobing works particularly well for phased array antennas because of the ability of such antennas to instantly scan to different beam pointing angles.
  • Sequential lobing involves taking RSSI measurements in a plurality of pointing directions around the last known pointing direction to the satellite 20. This is represented in Figures 3A and 3B.
  • Figure 3B shows taking RSSI measurements in five pointing directions around the last known pointing direction to the satellite 20.
  • a parabola 42 is fit to the three points, 0, 1 and 3 to determine the azimuth pointing angle.
  • a parabola 44 is formed by fitting it to the three points, 0, 2 and 4 taken to determine the elevation pointing angle. The highest point on each of the parabolas 42 and 44 represents a very close estimate of the target satellite position to which the receive antenna 12 is then steered.
  • the transmit beam is steered to the satellite target position estimated by the sequential lobing of the receive beam.
  • the transmit beam is usually slaved to the center point of the sequential lobing pattern of the receive beam.
  • slaving the pointing direction of the transmit antenna 14 to the pointing direction of the receive antenna 12 can introduce an unacceptable degree of misalignment of the transmit antenna 14. Accordingly, it will typically be required that the transmit and receive antenna beams be checked and corrected through some form of alignment or calibration process.
  • the RSSI at the ground station 18 is measured and recorded for each point in the transmit antenna 14 sequential lobing pattern, as indicated at step 52. It will be appreciated that a flag may need to be inserted into the return link data stream (represented by arrows 30 in Figure 1) to indicate the transition from one lobing point to another. This flag need be nothing more than a packet of data addressed to the ground station receiver 24.
  • the recorded RSSI measurements are fed back to the transmitter 28 via feedback loop 38 and transmitted via antenna 26, the target satellite 20 and the forward links 32 to the aircraft 16, as indicated at step 54.
  • a parabola is then fitted to the three points taken in azimuth and elevation, as indicated at step 56, to determine the peak angles of the parabola along the azimuth and elevation axes. These parabolas are indicated in Figures 4 and 5 and denoted by reference numerals 58 and 60, respectively.
  • the alignment error between the transmit and receive antenna beams is determined, as indicated at step 62. With reference to Figures 4 and 5, this alignment error is represented by distance 64 in Figure 4 and distance 66 in Figure 5. Distance 64 represents the azimuth alignment error between the transmit and receive antenna beams.
  • Distance 66 represents the elevation alignment error between the transmit and receive antenna beams.
  • each signal quality or signal strength measurement during the transmit sequential lobing cycle described above represents a direct measure of off-axis power density.
  • the above-described process for determining alignment errors may be performed at system power up or at any time during normal operation of the antennas 12 and 14.
  • the alignment calibration process does not interfere with normal operation of the communications links, does not require significant additional bandwidth to implement, and does not require significant additional equipment to be carried onboard the aircraft 16.
  • the apparatus 10 and method of the present invention thus allows antenna misalignments to be detected and corrected for without taking the aircraft 16 out of service, which would be considered undesirable to a commercial airline operating the aircraft.
  • the apparatus 10 and method of the present invention further eliminates the possibility of interference with adjacent satellites near the target satellite 20.
  • the parameter measured by the ground station receiver 24 can be used to verify the system 10 off-axis power density levels, verify the host platform 16 pointing and tracking performance, and verify the transmit beam pattern.
  • the transmit sequential lobing cycle By repeating the transmit sequential lobing cycle multiple times, it is possible to verify the host platform 16 pointing and tracking performance.
  • the variation in computed transmit beam center between lobing cycles will be due to inaccuracies in the host platform 16 antenna pointing and tracking system. By measuring these inaccuracies, it is possible to determine whether the host platform pointing and tracking system is functioning properly.
  • the parabolic fit made to the transmit sequential lobing measurements represents an approximation of the transmit beam pattern. This beam pattern can be compared to the expected transmit beam pattern of the host platform to verify the proper function of the transmit antenna 14. With additional sequential lobing data points, the approximation of transmit beam pattern can be refined.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Remote Sensing (AREA)
  • Astronomy & Astrophysics (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Radio Relay Systems (AREA)

Abstract

L'invention concerne un appareil et un procédé de correction du désalignement d'un faisceaux d'antenne entre une antenne de transmission et une antenne de réception sur une plate-forme mobile telle qu'un aéronef. Le procédé d'alignement de faisceaux utilise les franges séquentielles pour déterminer les angles de pointage dans l'azimut et l'altitude d'un faisceau de réception reçu par l'antenne de réception. Pour l'antenne de transmission, les franges séquentielles sont utilisées pour le faisceau d'antenne de transmission transmis à un satellite transpondeur, puis à une station terrestre. La station terrestre effectue des mesures d'indicateur d'intensité de signal reçu (RSSI), puis les transmet à un aéronef (16) via le satellite cible. Sur la base de ces mesures, le désalignement entre les faisceaux d'antenne de réception et de transmission, à la fois dans l'azimut et l'altitude, peut être déterminé et une correction appliquée à l'antenne de transmission. L'opération d'alignement de faisceaux peut être exécutée sans que l'utilisation normale des antennes de réception et de transmission ne soit perturbée, tout en empêchant les interférences de se produire avec un satellite adjacent au satellite cible au cours des transmissions de liaisons retour de l'aéronef à la station terrestre.
PCT/US2002/013743 2002-04-30 2002-04-30 Procedes d'alignement de faisceaux pour antenne WO2003094287A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
AU2002303571A AU2002303571A1 (en) 2002-04-30 2002-04-30 Beam alignment methods for an antenna
PCT/US2002/013743 WO2003094287A1 (fr) 2002-04-30 2002-04-30 Procedes d'alignement de faisceaux pour antenne

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US2002/013743 WO2003094287A1 (fr) 2002-04-30 2002-04-30 Procedes d'alignement de faisceaux pour antenne

Publications (1)

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WO2003094287A1 true WO2003094287A1 (fr) 2003-11-13

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WO (1) WO2003094287A1 (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007038332A2 (fr) * 2005-09-22 2007-04-05 Purdue Research Foundation Systeme d'orientation d'antenne, et procede d'acces sans fil a large bande
WO2010127224A1 (fr) * 2009-04-30 2010-11-04 Arsen Melconian Systèmes et procédés pour un alignement avec une source à distance
WO2018152198A1 (fr) * 2017-02-15 2018-08-23 Thinkom Solutions Procédés et systèmes de commande du pointage d'une ouverture d'antenne d'émission d'une antenne réseau à commande de phase par le réglage du niveau de puissance d'émission en fonction du rapport porteuse/bruit de la liaison à l'aide d'une boucle de commande grossière et plus fine
WO2019010213A1 (fr) * 2017-07-06 2019-01-10 Viasat, Inc. Étalonnage de décalage de plateforme d'antenne dynamique
CN114258066A (zh) * 2021-12-21 2022-03-29 中国联合网络通信集团有限公司 方位角异常检测方法、装置、设备和存储介质
EP4123926A1 (fr) * 2021-07-19 2023-01-25 Airspan IP Holdco LLC Détermination d'une correction devant être appliquée à un faisceau principal d'un système d'antenne pour un véhicule mobile

Citations (8)

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US3772701A (en) * 1971-02-11 1973-11-13 Communications Satellite Corp Satellite antenna autotrack system permitting error signals to appear at the earth station
US4963890A (en) * 1984-07-27 1990-10-16 Selenia Spazio S.P.A. Antenna tracking system using sequential lobing
US5463656A (en) * 1993-10-29 1995-10-31 Harris Corporation System for conducting video communications over satellite communication link with aircraft having physically compact, effectively conformal, phased array antenna
US5912642A (en) * 1998-04-28 1999-06-15 Ball Aerospace & Technologies Corp. Method and system for aligning a sensor on a platform
US6208307B1 (en) * 2000-04-07 2001-03-27 Live Tv, Inc. Aircraft in-flight entertainment system having wideband antenna steering and associated methods
US6417803B1 (en) * 2001-04-03 2002-07-09 The Boeing Company Beam alignment system and method for an antenna
US20020146982A1 (en) * 2001-04-04 2002-10-10 Mclain Christopher John Method and apparatus using transmit beam lobing for identifying an interfering mobile terminal
WO2002098016A2 (fr) * 2001-05-30 2002-12-05 The Boeing Company Procede de localisation et de communication precises avec un satellite a partir d'une plate-forme mobile

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3772701A (en) * 1971-02-11 1973-11-13 Communications Satellite Corp Satellite antenna autotrack system permitting error signals to appear at the earth station
US4963890A (en) * 1984-07-27 1990-10-16 Selenia Spazio S.P.A. Antenna tracking system using sequential lobing
US5463656A (en) * 1993-10-29 1995-10-31 Harris Corporation System for conducting video communications over satellite communication link with aircraft having physically compact, effectively conformal, phased array antenna
US5912642A (en) * 1998-04-28 1999-06-15 Ball Aerospace & Technologies Corp. Method and system for aligning a sensor on a platform
US6208307B1 (en) * 2000-04-07 2001-03-27 Live Tv, Inc. Aircraft in-flight entertainment system having wideband antenna steering and associated methods
US6417803B1 (en) * 2001-04-03 2002-07-09 The Boeing Company Beam alignment system and method for an antenna
US20020146982A1 (en) * 2001-04-04 2002-10-10 Mclain Christopher John Method and apparatus using transmit beam lobing for identifying an interfering mobile terminal
WO2002098016A2 (fr) * 2001-05-30 2002-12-05 The Boeing Company Procede de localisation et de communication precises avec un satellite a partir d'une plate-forme mobile

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007038332A3 (fr) * 2005-09-22 2009-04-16 Purdue Research Foundation Systeme d'orientation d'antenne, et procede d'acces sans fil a large bande
US9246207B2 (en) 2005-09-22 2016-01-26 Purdue Research Foundation Antenna aiming system and method for broadband wireless access
WO2007038332A2 (fr) * 2005-09-22 2007-04-05 Purdue Research Foundation Systeme d'orientation d'antenne, et procede d'acces sans fil a large bande
WO2010127224A1 (fr) * 2009-04-30 2010-11-04 Arsen Melconian Systèmes et procédés pour un alignement avec une source à distance
US8477068B2 (en) 2009-04-30 2013-07-02 Tecom Industries, Inc. Systems and methods for alignment with a remote source
IL268706B1 (en) * 2017-02-15 2024-02-01 Thinkom Solutions Inc Pointing systems, antenna array, transmission and methods.
WO2018152198A1 (fr) * 2017-02-15 2018-08-23 Thinkom Solutions Procédés et systèmes de commande du pointage d'une ouverture d'antenne d'émission d'une antenne réseau à commande de phase par le réglage du niveau de puissance d'émission en fonction du rapport porteuse/bruit de la liaison à l'aide d'une boucle de commande grossière et plus fine
IL268706B2 (en) * 2017-02-15 2024-06-01 Thinkom Solutions Inc Pointing systems, antenna array, transmission and methods.
US11133859B2 (en) 2017-02-15 2021-09-28 Thinkom Solutions, Inc. Transmit phased array antenna pointing systems and methods
WO2019010213A1 (fr) * 2017-07-06 2019-01-10 Viasat, Inc. Étalonnage de décalage de plateforme d'antenne dynamique
US10446906B2 (en) 2017-07-06 2019-10-15 Viasat, Inc. Dynamic antenna platform offset calibration
EP4123926A1 (fr) * 2021-07-19 2023-01-25 Airspan IP Holdco LLC Détermination d'une correction devant être appliquée à un faisceau principal d'un système d'antenne pour un véhicule mobile
CN114258066A (zh) * 2021-12-21 2022-03-29 中国联合网络通信集团有限公司 方位角异常检测方法、装置、设备和存储介质

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