US20070109190A1 - Antenna failure detection - Google Patents
Antenna failure detection Download PDFInfo
- Publication number
- US20070109190A1 US20070109190A1 US11/274,067 US27406705A US2007109190A1 US 20070109190 A1 US20070109190 A1 US 20070109190A1 US 27406705 A US27406705 A US 27406705A US 2007109190 A1 US2007109190 A1 US 2007109190A1
- Authority
- US
- United States
- Prior art keywords
- bearing
- target
- positional data
- bearings
- antenna
- Prior art date
- Legal status (The legal status 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 status listed.)
- Granted
Links
Images
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
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/40—Means for monitoring or calibrating
- G01S7/4004—Means for monitoring or calibrating of parts of a radar system
- G01S7/4026—Antenna boresight
- G01S7/403—Antenna boresight in azimuth, i.e. in the horizontal plane
-
- 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
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/88—Radar or analogous systems specially adapted for specific applications
- G01S13/93—Radar or analogous systems specially adapted for specific applications for anti-collision purposes
- G01S13/933—Radar or analogous systems specially adapted for specific applications for anti-collision purposes of aircraft or spacecraft
-
- 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
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/40—Means for monitoring or calibrating
- G01S7/4004—Means for monitoring or calibrating of parts of a radar system
- G01S7/4026—Antenna boresight
-
- 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
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/40—Means for monitoring or calibrating
- G01S7/4004—Means for monitoring or calibrating of parts of a radar system
- G01S7/4026—Antenna boresight
- G01S7/4034—Antenna boresight in elevation, i.e. in the vertical plane
Definitions
- the present invention relates to the detection of antenna failures, and more particularly to an apparatus, method, and computer-executable program for detecting antenna failures in directional antennas.
- TCAS Traffic Alert Collision Avoidance System
- Conventional directional antennas such as a Traffic Alert Collision Avoidance System (TCAS) directional antenna, are used in commercial, military, and private aircraft applications to detect and warn of potential collisions with other air traffic.
- TCAS Traffic Alert Collision Avoidance System
- directional antenna systems include some apparatus for detecting failures in the antenna.
- conventional directional antennas may employ internal test circuitry that is used to detect failures in the antenna and to ensure that the cables are correctly attached.
- FIG. 1 shows an example of a layout of such a circuit.
- the schematic of this circuitry is shown in FIG. 2 .
- the function of the test circuitry is centered on four resistors that can be sensed by a computer unit. Each resistor has a different resistance value so that each channel of the directional antenna has a unique DC characteristic for ease in detection and isolation of failure.
- these resistors are isolated by the use of capacitors so that each channel can be sensed independently.
- detection by a DC continuity check becomes difficult.
- the result of this undetected capacitor or solder joint failure is radiation pattern degradation. Such degradation can be the cause of traffic being displayed in the wrong location on the pilot's display. While the bearing of an intruder aircraft is not used to determine any resolution advisory information, the pilot's confidence in a system possibly displaying incorrect information may be eroded.
- VSWR detectors typically have large indeterminate zones where they are not reliable in detecting an out of specification VSWR.
- VSWR detectors are typically located in a computer unit (which is typically further isolated from the antenna by a cable with 2-3 dB attenuation), even more uncertainty is added.
- the present invention provides an apparatus, method, and computer-executable program for detecting antenna failures in directional antennas.
- the present invention compares a bearing calculated from received positional data concerning a target aircraft to the bearing of the target aircraft determined using the directional antenna. If the calculated bearing and the determined bearing differ by greater than a predetermined amount it is determined that there is an antenna failure. In this way, bearing information determined by the directional antenna is compared against another source of positional data in order to determine if the antenna is functioning properly. As such, antenna failures may be detected more precisely and with better confidence.
- the invention provides a method of detecting a failure of a directional antenna.
- the method comprises the steps of receiving positional data concerning a target, calculating a bearing to the target with the received positional data, determining a bearing of the target utilizing directional reception, generating an offset bearing, the offset bearing being the difference between the calculated bearing and the determined bearing, and informing of an antenna failure in the case that the bearing offset is greater than a predetermined error threshold.
- the invention provides a method that comprises the steps of receiving a plurality of positional data points concerning a target, calculating a plurality of bearings to the target with the received positional data points, and determining a plurality of bearings of the target utilizing directional reception.
- the method further includes the steps of generating a plurality of bearing offsets, the bearing offsets being the difference between the calculated bearings and the determined bearings, and informing of an antenna failure in the case that a current bearing offset differs from a previously generated bearing offset by an amount greater than a predetermined error threshold.
- the current bearing offset and the previously generated bearing offset may be consecutively generated bearing offsets or the previously generated bearing offset may have been calculated further back in time.
- a running average of current bearing offsets may be compared to a running average of previously generated bearing offsets.
- the above-described method may be carried out with a program stored on a computer-readable medium or with an apparatus, as will be discussed in more detail below.
- FIG. 1 depicts a circuit layout of a conventional antenna failure detection circuit.
- FIG. 2 depicts a schematic of a conventional antenna failure detection circuit.
- FIG. 3 depicts the typical operating environment of the invention.
- FIG. 4 depicts a block diagram of the apparatus according to one embodiment of the invention.
- FIG. 5 depicts a flowchart showing the method steps according to one embodiment of the invention.
- FIG. 6 is a graph of a conventional directional antenna pattern.
- FIG. 3 depicts a typical operating environment for the invention.
- Host aircraft 100 includes a directional antenna system 300 which includes directional antenna 310 .
- Host aircraft 100 is typically a commercial airliner or military aircraft, but may be any type of aircraft.
- Directional antenna system 300 and directional antenna 310 are used for, among other things, determining the bearing of other aircraft, such as target aircraft 200 .
- directional antenna system 300 is a Traffic Alert Collision Avoidance System (TCAS), however this invention is applicable to any type of directional antenna system.
- Bearings to target aircraft 200 are determined by sending an interrogation 110 and receiving a reply 120 utilizing the directional antenna system 300 .
- positional data 210 concerning target aircraft 200 may be received by host aircraft 100 from target aircraft 200 or from some other source, such as ground station 250 .
- the present invention utilizes received positional data 210 concerning target aircraft 200 to calculate a bearing to that aircraft. This calculated bearing is then compared to a bearing that is determined using directional antenna system 300 . If the difference between these two bearings is greater than some predetermined amount, it is determined that directional antenna 310 has failed.
- FIG. 4 depicts one embodiment of an apparatus according to the invention.
- the directional antenna system 300 includes a directional antenna 310 , a computer unit 320 , and an informing unit 330 .
- Directional antenna system 300 may also optionally include additional communication links 340 , including a data link 341 , a VHF communication link 342 , a GPS data link 344 , and/or an ADS-B communication link 345 . Communication among and between computer unit 320 , informing unit 330 , and communication links 340 is handled via bus 329 .
- Directional antenna 310 is preferably a TCAS directional antenna, however, as discussed above, the present invention is applicable for use with any type of directional antenna.
- Directional antenna 310 is coupled to the directional antenna system 300 for use by receiver 321 and/or transmitter 322 .
- directional antenna 310 may include an assembly mounted outside the fuselage (e.g., attached to the fuselage of host aircraft 100 and coupled to directional antenna system 300 by one or more cables) on the top and/or the bottom of the fuselage.
- An antenna assembly mounted on the top of the fuselage may be used in conjunction with or in place of a second antenna assembly on the bottom of the fuselage.
- Directional antenna 310 and receiver 321 may cooperate for directional reception.
- directional antenna 310 may include any conventional directional antenna and/or elements that may be operated for directional reception (e.g., amplitude monopulse or phase monopulse reception).
- directional reception e.g., amplitude monopulse or phase monopulse reception.
- One such technique for directional reception is described in “Systems and Methods for Determining Bearing” by Mark D. Smith (U.S. patent application Ser. No. 10/889,983 filed Jul. 12, 2004) which is hereby incorporated by reference.
- FIG. 6 illustrates the radiation pattern of a conventional directional antenna of the type used in an amplitude monopulse system.
- a conventional directional antenna of the type used in an amplitude monopulse system.
- Such an antenna typically detects in four quadrants.
- the signals illustrated were measured on a four foot diameter flat ground plane.
- This radiation pattern is desired for performance of the antenna on all aircraft.
- the performance of the antenna in each of the four quadrants representing aft 600 , port 610 , fore 620 , and starboard 630 is virtually identical.
- a conventional directional antenna system may use a model based on the radiation pattern of FIG. 6 .
- the bearing of the target is calculated by determining which beam of beams 600 , 610 , 620 , or 630 has the largest amplitude, determining which beam has the second largest amplitude, and taking the difference between the two. Based on this difference and the model, a bearing is determined.
- Bearings (uncorrected or corrected) are generally represented by an angular measurement in a plane (e.g., azimuth).
- Positional antenna 310 may also be used to receive positional data 210 from other target aircraft.
- Positional data 210 may include information such as altitude, latitude, and longitude (e.g., absolute coordinates), or relative position to another object or vehicle (e.g., relative position of a follower aircraft in a formation).
- positional data 210 is in the form of an Automatic Dependent Surveillance Broadcast (“ADS-B”) squitter, however the positional data may be in any format.
- a squitter is an unsolicited transmission of information.
- ADS-B squitters are typically transmitted periodically via an omni-directional antenna.
- positional data 210 may be received through one or more additional communication links 340 .
- receiver 321 and/or processor 324 may determine positional data from messages received in any of the following ways: (a) on any conventional data link, such as data link 341 (e.g., a network among formation members, station keeping equipment); (b) in a conventional air traffic control system MODE S format; (c) in Automatic Dependent Surveillance Broadcast (ADS-B) format, either through directional antenna 310 or an alternative ADS-B communication link 345 ; (d) in a transponder format; or (e) via VHF communication link 342 .
- ADS-B Automatic Dependent Surveillance Broadcast
- any conventional locator may be used, such as GPS data link 344 .
- Other implementations may include a subsystem cooperative with GLONASS satellites, a subsystem cooperative with the well known LORAN system, and/or an inertial navigation system.
- Computer unit 320 includes a receiver 321 , a transmitter 322 , a processor 324 , and a memory 325 each of which are connected to each other via bus 329 . Both receiver 321 and transmitter 322 are coupled to directional antenna 310 .
- Receiver 321 is configured to receive both transponder replies 120 as well as positional data 210 , such as ADS-B squitters. The received information is transmitted via bus 329 to processor 324 for further processing. Operation of receiver 321 may be independently controlled or may be controlled by processor 324 .
- Transmitter 322 is used to transmit directional antenna interrogations 110 . Operation of transmitter 322 may be independently controlled or may be controlled by processor 324 .
- Processor 324 includes any circuit that performs a method that may be recalled from memory and/or performed by logic circuitry.
- the circuit may include conventional logic circuit(s), controller(s), microprocessor(s), and state machine(s) in any combination.
- the method may be implemented in circuitry, firmware, and/or software. Any conventional circuitry may be used (e.g., multiple redundant microprocessors, application specific integrated circuits).
- processor 324 may include an Intel PENTIUM® microprocessor or a Motorola POWIERPC® microprocessor.
- Processor 324 cooperates with memory 325 to perform methods for detecting directional antenna failures as discussed herein.
- Processor 324 provides controls and receives status from receiver 321 and transmitter 322 . Use of antenna 310 by receiver 321 and transmitter 322 may be coordinated in any conventional manner by processor 324 and/or somewhat independently of processor 324 by each of receiver 321 and transmitter 322 .
- Memory 325 is used for storing data and program instructions in any suitable manner.
- Memory 325 may provide volatile and/or nonvolatile storage using any combination of conventional technology (e.g., semiconductors, magnetics, optics) in fixed and replaceable packaging.
- memory 325 may include random access storage for working values and persistent storage for program instructions and configuration data. Programs and data may be received by and stored in system 300 in any conventional manner.
- Directional antenna system 300 also includes an informing unit 330 .
- Informing unit 330 provides information to a flight crew member in audio and/or visual format. For example, informing unit 330 presents, among other things, bearing to each of several targets as determined by computer unit 320 .
- Informing unit 330 may include any conventional display (e.g., a VSI/TRA display).
- Computer unit 320 provides suitable signals to informing unit 330 for the display of bearing. Informing unit 330 may also issue traffic advisories and/or resolution advisories as directed by computer 320 .
- informing unit 330 issues a warning if computer 320 determines that there is a directional antenna failure. The warning may be either audible or visual.
- computer unit 320 will typically disable any display of directional reception on informing unit 330 in the case that an antenna failure has been detected.
- FIG. 5 depicts an embodiment of the method used to detect a directional antenna failure.
- the process for checking for an antenna failure is triggered by the receipt of positional data in step S 501 .
- the positional data may be received by directional antenna 310 in the form of an ADS-B squitter from target aircraft 200 .
- the ADS-B squitter may include information such as altitude, latitude, and longitude (e.g., absolute coordinates).
- similar information may be received over data link 341 or VHF communication link 342 .
- These communication links may be used in situations where the target aircraft does not have an ADS-B transponder. Instead, the target aircraft may transmit positional data over a general data link or a VHF communication link.
- positional data of target aircrafts may also be transmitted from a ground station to data link 341 or VHF communication link 342 .
- ADS-B squitters may also be received via a separate ADS-B communication link 345 in addition to or in place of directional antenna 310 .
- processor 324 receives the positional data of the target aircraft and calculates a bearing to the target aircraft.
- the bearing is calculated from the received positional data and the positional data of the host aircraft.
- the host aircraft's positional data may be determined, for example, with information received via a GPS data link 344 .
- Positional data 210 concerning the target aircraft as well as the host aircraft's positional data are transmitted to processor 324 via bus 329 .
- Processor 324 utilizes the positions of each of the aircrafts to calculate a bearing, represented, for example, as an angular measurement in a plane, to the target aircraft. This bearing is referred to as the “calculated bearing.”
- a bearing to the target aircraft i.e., the aircraft for which the positional data was received
- directional antenna 310 a bearing to the target aircraft (i.e., the aircraft for which the positional data was received) is determined using directional antenna 310 .
- directional reception may be achieved using any conventional manner.
- the resulting bearing is represented as an angular measurement in a plane. This bearing is referred to as the “determined bearing.”
- step S 504 the bearing calculated from the positional data is compared to the bearing determined by the directional antenna.
- the bearings are subtracted to generate a bearing offset.
- the bearing offset is stored in memory 325 .
- step S 505 based on the generated bearing offset, it is determined if there is an antenna failure. This determination may be done in several ways. One way to determine if there is an antenna failure is to simply compare the bearing offset generated in step S 504 to a predetermined error threshold. For example, an absolute bearing offset value of greater than 20 degrees would signify an antenna failure, however any suitable error threshold may be used.
- Another way to determine if there is an antenna failure is to compare the currently calculated bearing offset with bearing offsets that have been previously stored in memory 325 .
- an increase in bearing offset from consecutively generated bearing offsets may indicate an antenna failure.
- the error threshold between consecutive bearing offsets may be any suitable value. For example, a change in bearing offset of 20 degrees may be used to indicate an antenna failure.
- a current bearing offset may be beneficial to compare to bearing offsets generated further back in time. For example, it may beneficial to compare the current bearing offset to the previously generated bearing offset, as well as the bearing offsets generated from fifth, tenth, and twentieth previously calculated bearing offsets. This would allow for detection of antenna failure in the situation of gradual antenna failure. In such situations, any two consecutive bearing offsets may not produce a difference that is greater than an error threshold (e.g., 20 degrees). However, the current bearing offset may be considerably greater or less than bearing offsets generated further back in time. Comparison to these older bearing offsets would then allow for detection of such a gradual antenna failure.
- an error threshold e.g. 20 degrees
- Determination of an antenna failure need not be limited to the comparison of individual bearing offsets, but may also include a comparison made between averages of bearing offsets. For instance, a running average of current bearing offsets may be compared to a running average of bearing offsets generated at a point further back in time. As one example, a running average of the twenty most current bearing offsets (t 0 to t ⁇ 19 ) may be compared to a running average of twenty bearing offsets that were previously generated (e.g. t ⁇ 100 to t ⁇ 119 ). A difference between the current and previously calculated running averages that is greater than some predetermined error threshold (e.g. 20 degrees) would indicate an antenna failure. As such, by comparing a current running average of bearing offsets against a previously generated running average, the determination of antenna failures would include a “filtering” capability so that an antenna failure would not be determined based on a single bad bearing offset or “glitch.”
- some predetermined error threshold e.g. 20 degrees
- the 360 degree azimuth coverage of the antenna can be broken into any number of segments. In such cases, only bearing offsets (or averages of bearing offsets) generated from bearings determined to be in a certain segment will be compared to each other for the purposes of detecting antenna failures.
- bearing offsets may be separated into four equal groups as there are generally four antenna quadrants in conventional directional antennas.
- bearing offsets may be separated in eight equal groups about the 360 degree azimuth coverage to reflect the eight regions of antenna response of a conventional directional antenna (see FIG. 6 ). However, any grouping of bearing offsets for comparison may be used.
- the method for detecting antenna failures may be implemented in circuitry, firmware, and/or software.
- any conventional circuitry may be used (e.g., multiple redundant microprocessors, application specific integrated circuits).
- the circuitry may include conventional logic circuit(s), controller(s), microprocessor(s), and state machine(s) in any combination.
- the method may be implemented as a software program stored in memory 325 and executed by processor 324 or by any conventional method utilizing software.
Abstract
Description
- 1. Field of the Invention
- The present invention relates to the detection of antenna failures, and more particularly to an apparatus, method, and computer-executable program for detecting antenna failures in directional antennas.
- 2. Background of the Invention
- Conventional directional antennas, such as a Traffic Alert Collision Avoidance System (TCAS) directional antenna, are used in commercial, military, and private aircraft applications to detect and warn of potential collisions with other air traffic. Typically, such directional antenna systems include some apparatus for detecting failures in the antenna. For example, conventional directional antennas may employ internal test circuitry that is used to detect failures in the antenna and to ensure that the cables are correctly attached.
-
FIG. 1 shows an example of a layout of such a circuit. The schematic of this circuitry is shown inFIG. 2 . The function of the test circuitry is centered on four resistors that can be sensed by a computer unit. Each resistor has a different resistance value so that each channel of the directional antenna has a unique DC characteristic for ease in detection and isolation of failure. However, these resistors are isolated by the use of capacitors so that each channel can be sensed independently. As such, when one of the capacitors or solder joints fails as an open circuit, detection by a DC continuity check becomes difficult. This results in an undetected failure mode of the antenna. The result of this undetected capacitor or solder joint failure is radiation pattern degradation. Such degradation can be the cause of traffic being displayed in the wrong location on the pilot's display. While the bearing of an intruder aircraft is not used to determine any resolution advisory information, the pilot's confidence in a system possibly displaying incorrect information may be eroded. - Other solutions for antenna failure detection have made use of detecting the voltage standing wave ratio (VSWR) of the antenna ports and characterizing what VSWR values relate to a failed capacitor (open circuit). Unfortunately, VSWR detectors typically have large indeterminate zones where they are not reliable in detecting an out of specification VSWR. In addition, as VSWR detectors are typically located in a computer unit (which is typically further isolated from the antenna by a cable with 2-3 dB attenuation), even more uncertainty is added.
- In view of the foregoing, the present invention provides an apparatus, method, and computer-executable program for detecting antenna failures in directional antennas. In particular, the present invention compares a bearing calculated from received positional data concerning a target aircraft to the bearing of the target aircraft determined using the directional antenna. If the calculated bearing and the determined bearing differ by greater than a predetermined amount it is determined that there is an antenna failure. In this way, bearing information determined by the directional antenna is compared against another source of positional data in order to determine if the antenna is functioning properly. As such, antenna failures may be detected more precisely and with better confidence.
- According to one embodiment, the invention provides a method of detecting a failure of a directional antenna. The method comprises the steps of receiving positional data concerning a target, calculating a bearing to the target with the received positional data, determining a bearing of the target utilizing directional reception, generating an offset bearing, the offset bearing being the difference between the calculated bearing and the determined bearing, and informing of an antenna failure in the case that the bearing offset is greater than a predetermined error threshold.
- According to another embodiment, the invention provides a method that comprises the steps of receiving a plurality of positional data points concerning a target, calculating a plurality of bearings to the target with the received positional data points, and determining a plurality of bearings of the target utilizing directional reception. The method further includes the steps of generating a plurality of bearing offsets, the bearing offsets being the difference between the calculated bearings and the determined bearings, and informing of an antenna failure in the case that a current bearing offset differs from a previously generated bearing offset by an amount greater than a predetermined error threshold. The current bearing offset and the previously generated bearing offset may be consecutively generated bearing offsets or the previously generated bearing offset may have been calculated further back in time. In addition, rather than comparing single bearing offsets, a running average of current bearing offsets may be compared to a running average of previously generated bearing offsets.
- The above-described method may be carried out with a program stored on a computer-readable medium or with an apparatus, as will be discussed in more detail below.
- It is to be understood that the descriptions of this invention herein are exemplary and explanatory only and are not restrictive of the invention as claimed.
-
FIG. 1 depicts a circuit layout of a conventional antenna failure detection circuit. -
FIG. 2 depicts a schematic of a conventional antenna failure detection circuit. -
FIG. 3 depicts the typical operating environment of the invention. -
FIG. 4 depicts a block diagram of the apparatus according to one embodiment of the invention. -
FIG. 5 depicts a flowchart showing the method steps according to one embodiment of the invention. -
FIG. 6 is a graph of a conventional directional antenna pattern. - Reference will now be made in detail to the present exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings.
- The present invention provides an apparatus, method, and computer-executable program for detecting antenna failures in directional antennas.
FIG. 3 depicts a typical operating environment for the invention.Host aircraft 100 includes adirectional antenna system 300 which includesdirectional antenna 310.Host aircraft 100 is typically a commercial airliner or military aircraft, but may be any type of aircraft.Directional antenna system 300 anddirectional antenna 310 are used for, among other things, determining the bearing of other aircraft, such astarget aircraft 200. Preferably,directional antenna system 300 is a Traffic Alert Collision Avoidance System (TCAS), however this invention is applicable to any type of directional antenna system. Bearings to targetaircraft 200 are determined by sending aninterrogation 110 and receiving areply 120 utilizing thedirectional antenna system 300. Additionally,positional data 210 concerningtarget aircraft 200 may be received byhost aircraft 100 fromtarget aircraft 200 or from some other source, such asground station 250. - In general, the present invention utilizes received
positional data 210 concerningtarget aircraft 200 to calculate a bearing to that aircraft. This calculated bearing is then compared to a bearing that is determined usingdirectional antenna system 300. If the difference between these two bearings is greater than some predetermined amount, it is determined thatdirectional antenna 310 has failed. -
FIG. 4 depicts one embodiment of an apparatus according to the invention. Thedirectional antenna system 300 includes adirectional antenna 310, acomputer unit 320, and an informingunit 330.Directional antenna system 300 may also optionally includeadditional communication links 340, including adata link 341, aVHF communication link 342, aGPS data link 344, and/or an ADS-B communication link 345. Communication among and betweencomputer unit 320, informingunit 330, andcommunication links 340 is handled viabus 329. -
Directional antenna 310 is preferably a TCAS directional antenna, however, as discussed above, the present invention is applicable for use with any type of directional antenna.Directional antenna 310 is coupled to thedirectional antenna system 300 for use byreceiver 321 and/ortransmitter 322. For example,directional antenna 310 may include an assembly mounted outside the fuselage (e.g., attached to the fuselage ofhost aircraft 100 and coupled todirectional antenna system 300 by one or more cables) on the top and/or the bottom of the fuselage. An antenna assembly mounted on the top of the fuselage may be used in conjunction with or in place of a second antenna assembly on the bottom of the fuselage.Directional antenna 310 andreceiver 321 may cooperate for directional reception. For example,directional antenna 310 may include any conventional directional antenna and/or elements that may be operated for directional reception (e.g., amplitude monopulse or phase monopulse reception). One such technique for directional reception is described in “Systems and Methods for Determining Bearing” by Mark D. Smith (U.S. patent application Ser. No. 10/889,983 filed Jul. 12, 2004) which is hereby incorporated by reference. - As one example of directional reception,
FIG. 6 illustrates the radiation pattern of a conventional directional antenna of the type used in an amplitude monopulse system. Such an antenna typically detects in four quadrants. The signals illustrated were measured on a four foot diameter flat ground plane. This radiation pattern is desired for performance of the antenna on all aircraft. As shown, the performance of the antenna in each of the four quadrants representing aft 600,port 610, fore 620, andstarboard 630 is virtually identical. To determine the bearing of a target, a conventional directional antenna system may use a model based on the radiation pattern ofFIG. 6 . When a target is detected viainterrogation 110 andreply 120, the bearing of the target is calculated by determining which beam ofbeams -
Directional antenna 310 may also be used to receivepositional data 210 from other target aircraft.Positional data 210 may include information such as altitude, latitude, and longitude (e.g., absolute coordinates), or relative position to another object or vehicle (e.g., relative position of a follower aircraft in a formation). Typically,positional data 210 is in the form of an Automatic Dependent Surveillance Broadcast (“ADS-B”) squitter, however the positional data may be in any format. A squitter is an unsolicited transmission of information. ADS-B squitters are typically transmitted periodically via an omni-directional antenna. - Alternatively,
positional data 210 may be received through one or more additional communication links 340. For example,receiver 321 and/orprocessor 324 may determine positional data from messages received in any of the following ways: (a) on any conventional data link, such as data link 341 (e.g., a network among formation members, station keeping equipment); (b) in a conventional air traffic control system MODE S format; (c) in Automatic Dependent Surveillance Broadcast (ADS-B) format, either throughdirectional antenna 310 or an alternative ADS-B communication link 345; (d) in a transponder format; or (e) viaVHF communication link 342. - In addition to positional data concerning target aircrafts, it is also beneficial to determine the position of
host aircraft 100. In this regard, any conventional locator may be used, such asGPS data link 344. Other implementations may include a subsystem cooperative with GLONASS satellites, a subsystem cooperative with the well known LORAN system, and/or an inertial navigation system. - The directional antenna information and the positional data that are received by
directional antenna 310, as well as any positional data concerninghost aircraft 100 andtarget aircraft 200 received bycommunication links 340, are processed bycomputer unit 320.Computer unit 320 includes areceiver 321, atransmitter 322, aprocessor 324, and amemory 325 each of which are connected to each other viabus 329. Bothreceiver 321 andtransmitter 322 are coupled todirectional antenna 310. -
Receiver 321 is configured to receive both transponder replies 120 as well aspositional data 210, such as ADS-B squitters. The received information is transmitted viabus 329 toprocessor 324 for further processing. Operation ofreceiver 321 may be independently controlled or may be controlled byprocessor 324. -
Transmitter 322 is used to transmitdirectional antenna interrogations 110. Operation oftransmitter 322 may be independently controlled or may be controlled byprocessor 324. -
Processor 324 includes any circuit that performs a method that may be recalled from memory and/or performed by logic circuitry. The circuit may include conventional logic circuit(s), controller(s), microprocessor(s), and state machine(s) in any combination. The method may be implemented in circuitry, firmware, and/or software. Any conventional circuitry may be used (e.g., multiple redundant microprocessors, application specific integrated circuits). For example,processor 324 may include an Intel PENTIUM® microprocessor or a Motorola POWIERPC® microprocessor.Processor 324 cooperates withmemory 325 to perform methods for detecting directional antenna failures as discussed herein.Processor 324 provides controls and receives status fromreceiver 321 andtransmitter 322. Use ofantenna 310 byreceiver 321 andtransmitter 322 may be coordinated in any conventional manner byprocessor 324 and/or somewhat independently ofprocessor 324 by each ofreceiver 321 andtransmitter 322. -
Memory 325 is used for storing data and program instructions in any suitable manner.Memory 325 may provide volatile and/or nonvolatile storage using any combination of conventional technology (e.g., semiconductors, magnetics, optics) in fixed and replaceable packaging. For example,memory 325 may include random access storage for working values and persistent storage for program instructions and configuration data. Programs and data may be received by and stored insystem 300 in any conventional manner. -
Directional antenna system 300 also includes an informingunit 330. Informingunit 330 provides information to a flight crew member in audio and/or visual format. For example, informingunit 330 presents, among other things, bearing to each of several targets as determined bycomputer unit 320. Informingunit 330 may include any conventional display (e.g., a VSI/TRA display).Computer unit 320 provides suitable signals to informingunit 330 for the display of bearing. Informingunit 330 may also issue traffic advisories and/or resolution advisories as directed bycomputer 320. In addition, informingunit 330 issues a warning ifcomputer 320 determines that there is a directional antenna failure. The warning may be either audible or visual. In addition to the warning,computer unit 320 will typically disable any display of directional reception on informingunit 330 in the case that an antenna failure has been detected. -
FIG. 5 depicts an embodiment of the method used to detect a directional antenna failure. The process for checking for an antenna failure is triggered by the receipt of positional data in step S501. For example, the positional data may be received bydirectional antenna 310 in the form of an ADS-B squitter fromtarget aircraft 200. The ADS-B squitter may include information such as altitude, latitude, and longitude (e.g., absolute coordinates). Alternatively, similar information may be received over data link 341 orVHF communication link 342. These communication links may be used in situations where the target aircraft does not have an ADS-B transponder. Instead, the target aircraft may transmit positional data over a general data link or a VHF communication link. In addition, positional data of target aircrafts may also be transmitted from a ground station to data link 341 orVHF communication link 342. ADS-B squitters may also be received via a separate ADS-B communication link 345 in addition to or in place ofdirectional antenna 310. - Next, in step S502,
processor 324 receives the positional data of the target aircraft and calculates a bearing to the target aircraft. The bearing is calculated from the received positional data and the positional data of the host aircraft. As discussed above, the host aircraft's positional data may be determined, for example, with information received via aGPS data link 344.Positional data 210 concerning the target aircraft as well as the host aircraft's positional data are transmitted toprocessor 324 viabus 329.Processor 324 utilizes the positions of each of the aircrafts to calculate a bearing, represented, for example, as an angular measurement in a plane, to the target aircraft. This bearing is referred to as the “calculated bearing.” - In step S503, a bearing to the target aircraft (i.e., the aircraft for which the positional data was received) is determined using
directional antenna 310. As explained above, directional reception may be achieved using any conventional manner. Typically, the resulting bearing is represented as an angular measurement in a plane. This bearing is referred to as the “determined bearing.” - In step S504, the bearing calculated from the positional data is compared to the bearing determined by the directional antenna. The bearings are subtracted to generate a bearing offset. The bearing offset is stored in
memory 325. - In step S505, based on the generated bearing offset, it is determined if there is an antenna failure. This determination may be done in several ways. One way to determine if there is an antenna failure is to simply compare the bearing offset generated in step S504 to a predetermined error threshold. For example, an absolute bearing offset value of greater than 20 degrees would signify an antenna failure, however any suitable error threshold may be used.
- However, as one would typically expect some error in both the directional antenna determination of bearing and in the calculation of bearing from two pieces of positional data, more accuracy for determining antenna failure may be achieved by looking at a historical record of bearing offsets rather than just one bearing offset. In this regard, another way to determine if there is an antenna failure is to compare the currently calculated bearing offset with bearing offsets that have been previously stored in
memory 325. For example, an increase in bearing offset from consecutively generated bearing offsets may indicate an antenna failure. As before, the error threshold between consecutive bearing offsets may be any suitable value. For example, a change in bearing offset of 20 degrees may be used to indicate an antenna failure. - In addition to determining antenna failures from consecutive bearing offsets, it may also be beneficial to compare a current bearing offset to bearing offsets generated further back in time. For example, it may beneficial to compare the current bearing offset to the previously generated bearing offset, as well as the bearing offsets generated from fifth, tenth, and twentieth previously calculated bearing offsets. This would allow for detection of antenna failure in the situation of gradual antenna failure. In such situations, any two consecutive bearing offsets may not produce a difference that is greater than an error threshold (e.g., 20 degrees). However, the current bearing offset may be considerably greater or less than bearing offsets generated further back in time. Comparison to these older bearing offsets would then allow for detection of such a gradual antenna failure.
- Determination of an antenna failure need not be limited to the comparison of individual bearing offsets, but may also include a comparison made between averages of bearing offsets. For instance, a running average of current bearing offsets may be compared to a running average of bearing offsets generated at a point further back in time. As one example, a running average of the twenty most current bearing offsets (t0 to t−19) may be compared to a running average of twenty bearing offsets that were previously generated (e.g. t−100 to t−119). A difference between the current and previously calculated running averages that is greater than some predetermined error threshold (e.g. 20 degrees) would indicate an antenna failure. As such, by comparing a current running average of bearing offsets against a previously generated running average, the determination of antenna failures would include a “filtering” capability so that an antenna failure would not be determined based on a single bad bearing offset or “glitch.”
- As described above, all individual bearing offsets and averages of bearing offsets, without consideration of which quadrant of the directional antenna received
reply 120, are compared to each other for determination of an antenna failure. However, it may be beneficial to limit comparisons of bearing offsets to offsets that were generated from bearings determined by the directional antenna in a predefined arc of the antenna's coverage. In this way, the 360 degree azimuth coverage may be split up into smaller sections to cover a smaller segment of the antenna performance, and as such, detection of antenna failures may be pinpointed to specific antenna quadrants. For example, this technique would cover the case where a capacitor failure only affects one beam (i.e. quadrant of the antenna), so that a number of “good” offsets are not averaged with a failed offset, thus failing to detect a failure. - The 360 degree azimuth coverage of the antenna can be broken into any number of segments. In such cases, only bearing offsets (or averages of bearing offsets) generated from bearings determined to be in a certain segment will be compared to each other for the purposes of detecting antenna failures. As one example, bearing offsets may be separated into four equal groups as there are generally four antenna quadrants in conventional directional antennas. As another example, bearing offsets may be separated in eight equal groups about the 360 degree azimuth coverage to reflect the eight regions of antenna response of a conventional directional antenna (see
FIG. 6 ). However, any grouping of bearing offsets for comparison may be used. - As discussed above, the method for detecting antenna failures may be implemented in circuitry, firmware, and/or software. For example, any conventional circuitry may be used (e.g., multiple redundant microprocessors, application specific integrated circuits). The circuitry may include conventional logic circuit(s), controller(s), microprocessor(s), and state machine(s) in any combination. In addition, to hardwired circuitry and/or firmware, the method may be implemented as a software program stored in
memory 325 and executed byprocessor 324 or by any conventional method utilizing software. - Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and embodiments disclosed herein. Thus, the specification and examples are exemplary only, with the true scope and spirit of the invention set forth in the following claims and legal equivalents thereof.
Claims (39)
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/274,067 US7218277B1 (en) | 2005-11-14 | 2005-11-14 | Antenna failure detection |
PCT/US2006/044659 WO2007059308A2 (en) | 2005-11-14 | 2006-11-14 | Antenna failure detection |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/274,067 US7218277B1 (en) | 2005-11-14 | 2005-11-14 | Antenna failure detection |
Publications (2)
Publication Number | Publication Date |
---|---|
US7218277B1 US7218277B1 (en) | 2007-05-15 |
US20070109190A1 true US20070109190A1 (en) | 2007-05-17 |
Family
ID=37909489
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/274,067 Active US7218277B1 (en) | 2005-11-14 | 2005-11-14 | Antenna failure detection |
Country Status (2)
Country | Link |
---|---|
US (1) | US7218277B1 (en) |
WO (1) | WO2007059308A2 (en) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2010012842A1 (en) * | 2008-08-01 | 2010-02-04 | Thales | Improvement to the locating of aircraft by a primary radar by utilizing a secondary radar in s mode |
US20100124164A1 (en) * | 2008-11-19 | 2010-05-20 | Harris Corporation | Code division multiple access based contingency transmission |
US20110001654A1 (en) * | 2009-07-03 | 2011-01-06 | Airbus Operations (Sas) | Process and a device for detecting aircrafts circulating in an air space surrounding an airplane |
US20110267216A1 (en) * | 2010-04-28 | 2011-11-03 | Smith Mark D | Systems and methods for providing antenna calibration |
EP2799895A1 (en) * | 2013-05-02 | 2014-11-05 | The Boeing Company | Device, system and methods using angle of arrival measurements for ads-b authentication and navigation |
US10288722B2 (en) * | 2014-10-03 | 2019-05-14 | Kustom Signals, Inc. | Traffic radar system with automated tuning fork test feature |
Families Citing this family (18)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2898686B1 (en) * | 2006-03-14 | 2008-05-23 | Thales Sa | AIRCRAFT EQUIPMENT FOR PREVENTING COLLISION RISK |
CN101933237A (en) * | 2008-02-01 | 2010-12-29 | Nxp股份有限公司 | Power supply control in a wireless receiver |
JP2010206357A (en) * | 2009-03-02 | 2010-09-16 | Fujitsu Ltd | Radio transmitting and receiving apparatus |
WO2012021547A2 (en) | 2010-08-10 | 2012-02-16 | Aviation Communication & Survellance Systems Llc | Systems and methods for providing spoof detection |
US20160286510A1 (en) * | 2014-10-31 | 2016-09-29 | Telefonaktiebolaget L M Ericsson (Publ) | Methods and systems for synchronizing a communication node in a communication network |
EP3356850B1 (en) * | 2015-09-28 | 2022-12-21 | Aviation Communication & Surveillance Systems LLC | Distributed antenna array systems and methods |
US10470114B2 (en) | 2016-06-30 | 2019-11-05 | General Electric Company | Wireless network selection |
US10318451B2 (en) | 2016-06-30 | 2019-06-11 | Ge Aviation Systems Llc | Management of data transfers |
US10467016B2 (en) | 2016-06-30 | 2019-11-05 | General Electric Company | Managing an image boot |
US10200110B2 (en) | 2016-06-30 | 2019-02-05 | Ge Aviation Systems Llc | Aviation protocol conversion |
US10444748B2 (en) | 2016-06-30 | 2019-10-15 | Ge Aviation Systems Llc | In-situ measurement logging by wireless communication unit for communicating engine data |
US10764747B2 (en) | 2016-06-30 | 2020-09-01 | Ge Aviation Systems Llc | Key management for wireless communication system for communicating engine data |
US10681132B2 (en) | 2016-06-30 | 2020-06-09 | Ge Aviation Systems Llc | Protocol for communicating engine data to wireless communication unit |
US10529150B2 (en) | 2016-06-30 | 2020-01-07 | Aviation Systems LLC | Remote data loading for configuring wireless communication unit for communicating engine data |
US10819601B2 (en) | 2016-06-30 | 2020-10-27 | Ge Aviation Systems Llc | Wireless control unit server for conducting connectivity test |
US10712377B2 (en) | 2016-06-30 | 2020-07-14 | Ge Aviation Systems Llc | Antenna diagnostics for wireless communication unit for communicating engine data |
US20190075507A1 (en) * | 2017-09-06 | 2019-03-07 | Jiejun Kong | Radio-Rate-Transformer: A Practical and Legal Radio Combo Transforming VHF/UHF Radio Communication to Gigahertz Broadband Radio Communication |
US11115792B2 (en) | 2017-06-15 | 2021-09-07 | Jiejun Kong | Vehicular high-speed network system |
Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5191349A (en) * | 1990-08-08 | 1993-03-02 | Honeywell Inc. | Apparatus and method for an amplitude monopulse directional antenna |
US6329947B2 (en) * | 1999-10-12 | 2001-12-11 | Mark D. Smith | System for processing directional signals |
US6480522B1 (en) * | 1997-12-18 | 2002-11-12 | At&T Wireless Services, Inc. | Method of polling second stations for functional quality and maintenance data in a discrete multitone spread spectrum communications system |
US20030093187A1 (en) * | 2001-10-01 | 2003-05-15 | Kline & Walker, Llc | PFN/TRAC systemTM FAA upgrades for accountable remote and robotics control to stop the unauthorized use of aircraft and to improve equipment management and public safety in transportation |
US6690321B1 (en) * | 2002-07-22 | 2004-02-10 | Bae Systems Information And Electronic Systems Integration Inc. | Multi-sensor target counting and localization system |
US6792058B1 (en) * | 2000-07-12 | 2004-09-14 | Lockheed Martin Corporation | Digital receiving system for dense environment of aircraft |
US6795772B2 (en) * | 2001-06-23 | 2004-09-21 | American Gnc Corporation | Method and system for intelligent collision detection and warning |
US6799114B2 (en) * | 2001-11-20 | 2004-09-28 | Garmin At, Inc. | Systems and methods for correlation in an air traffic control system of interrogation-based target positional data and GPS-based intruder positional data |
US20060009909A1 (en) * | 2004-07-12 | 2006-01-12 | Aviation Communication & Surveillance Systems Llc | Systems and methods for determining bearing |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2213339A (en) * | 1987-12-02 | 1989-08-09 | Secr Defence | Relative position determination |
US6064335A (en) * | 1997-07-21 | 2000-05-16 | Trimble Navigation Limited | GPS based augmented reality collision avoidance system |
US6542810B2 (en) * | 2000-07-10 | 2003-04-01 | United Parcel Service Of America, Inc. | Multisource target correlation |
US6690917B2 (en) * | 2001-11-15 | 2004-02-10 | Qualcomm Incorporated | System and method for automatic determination of azimuthal and elevation direction of directional antennas and calibration thereof |
EP1389735A1 (en) * | 2002-08-16 | 2004-02-18 | Siemens Aktiengesellschaft | System and method for determining the angle of the relative alignment of an antenna array of a radio system |
US7006032B2 (en) * | 2004-01-15 | 2006-02-28 | Honeywell International, Inc. | Integrated traffic surveillance apparatus |
-
2005
- 2005-11-14 US US11/274,067 patent/US7218277B1/en active Active
-
2006
- 2006-11-14 WO PCT/US2006/044659 patent/WO2007059308A2/en active Application Filing
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5191349A (en) * | 1990-08-08 | 1993-03-02 | Honeywell Inc. | Apparatus and method for an amplitude monopulse directional antenna |
US6480522B1 (en) * | 1997-12-18 | 2002-11-12 | At&T Wireless Services, Inc. | Method of polling second stations for functional quality and maintenance data in a discrete multitone spread spectrum communications system |
US6329947B2 (en) * | 1999-10-12 | 2001-12-11 | Mark D. Smith | System for processing directional signals |
US6792058B1 (en) * | 2000-07-12 | 2004-09-14 | Lockheed Martin Corporation | Digital receiving system for dense environment of aircraft |
US6795772B2 (en) * | 2001-06-23 | 2004-09-21 | American Gnc Corporation | Method and system for intelligent collision detection and warning |
US20030093187A1 (en) * | 2001-10-01 | 2003-05-15 | Kline & Walker, Llc | PFN/TRAC systemTM FAA upgrades for accountable remote and robotics control to stop the unauthorized use of aircraft and to improve equipment management and public safety in transportation |
US6799114B2 (en) * | 2001-11-20 | 2004-09-28 | Garmin At, Inc. | Systems and methods for correlation in an air traffic control system of interrogation-based target positional data and GPS-based intruder positional data |
US6690321B1 (en) * | 2002-07-22 | 2004-02-10 | Bae Systems Information And Electronic Systems Integration Inc. | Multi-sensor target counting and localization system |
US20060009909A1 (en) * | 2004-07-12 | 2006-01-12 | Aviation Communication & Surveillance Systems Llc | Systems and methods for determining bearing |
Cited By (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2934688A1 (en) * | 2008-08-01 | 2010-02-05 | Thales Sa | IMPROVING THE LOCATION OF AIRCRAFT BY PRIMARY RADAR BY OPERATING A SECONDARY RADAR IN MODE S. |
WO2010012842A1 (en) * | 2008-08-01 | 2010-02-04 | Thales | Improvement to the locating of aircraft by a primary radar by utilizing a secondary radar in s mode |
US8169886B2 (en) * | 2008-11-19 | 2012-05-01 | Harris Corporation | Code division multiple access based contingency transmission |
US20100124164A1 (en) * | 2008-11-19 | 2010-05-20 | Harris Corporation | Code division multiple access based contingency transmission |
US20110001654A1 (en) * | 2009-07-03 | 2011-01-06 | Airbus Operations (Sas) | Process and a device for detecting aircrafts circulating in an air space surrounding an airplane |
FR2947639A1 (en) * | 2009-07-03 | 2011-01-07 | Airbus Operations Sas | METHOD AND DEVICE FOR DETECTING CIRCULATING AIRCRAFT IN AN AIRSPACE SURROUNDING AN AIRCRAFT |
US8390505B2 (en) * | 2009-07-03 | 2013-03-05 | Airbus Operations (Sas) | Process and a device for detecting aircrafts circulating in an air space surrounding an airplane |
US20110267216A1 (en) * | 2010-04-28 | 2011-11-03 | Smith Mark D | Systems and methods for providing antenna calibration |
US9024812B2 (en) * | 2010-04-28 | 2015-05-05 | Aviation Communication & Surveillance Systems Llc | Systems and methods for providing antenna calibration |
EP2799895A1 (en) * | 2013-05-02 | 2014-11-05 | The Boeing Company | Device, system and methods using angle of arrival measurements for ads-b authentication and navigation |
US20140327581A1 (en) * | 2013-05-02 | 2014-11-06 | The Boeing Company | Device, System and Methods Using Angle of Arrival Measurements for ADS-B Authentication and Navigation |
US9476962B2 (en) * | 2013-05-02 | 2016-10-25 | The Boeing Company | Device, system and methods using angle of arrival measurements for ADS-B authentication and navigation |
AU2014200613B2 (en) * | 2013-05-02 | 2017-04-27 | The Boeing Company | Device, system and methods using angle of arrival measurements for ADS-B authentication and navigation |
US10365374B2 (en) | 2013-05-02 | 2019-07-30 | The Boeing Company | Device, system and methods using angle of arrival measurements for ADS-B authentication and navigation |
US10288722B2 (en) * | 2014-10-03 | 2019-05-14 | Kustom Signals, Inc. | Traffic radar system with automated tuning fork test feature |
Also Published As
Publication number | Publication date |
---|---|
US7218277B1 (en) | 2007-05-15 |
WO2007059308A3 (en) | 2007-07-12 |
WO2007059308A2 (en) | 2007-05-24 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7218277B1 (en) | Antenna failure detection | |
EP1794618B1 (en) | Methods and systems of determining bearing when ads-b data is unavailable | |
US7272472B1 (en) | System and method for improving aircraft formation flying accuracy and integrity | |
KR100776548B1 (en) | Method for calculating a bearing of a signal source, system for determining a bearing to a radio signal source and computer for use in aircraft | |
EP2603814B1 (en) | Method for providing spoof detection | |
US6094169A (en) | Multilateration auto-calibration and position error correction | |
US7864096B2 (en) | Systems and methods for multi-sensor collision avoidance | |
US8130135B2 (en) | Bi-static radar processing for ADS-B sensors | |
US20070200761A1 (en) | Method and apparatus for improving ads-b security | |
US20070222666A1 (en) | Collision risk prevention equipment for aircraft | |
WO2007005031A1 (en) | Systems and methods for determining bearing | |
EP2165212A2 (en) | Methods and apparatus for using interferometry to prevent spoofing of ads-b targets | |
US11867796B2 (en) | Secondary radar improving aerial safety via very-long-range ADS-B detection | |
CA3097218A1 (en) | Method and apparatus for ensuring aviation safety in the presence of ownship aircrafts | |
US9100087B2 (en) | Systems and methods for providing surface multipath mitigation | |
EP3989464A1 (en) | Detection of gnss interference using surveillance messages | |
US7551120B1 (en) | Method and a system for filtering tracks originating from several sources and intended for several clients to which they are supplied | |
US8390505B2 (en) | Process and a device for detecting aircrafts circulating in an air space surrounding an airplane | |
CN108154716B (en) | Airborne collision avoidance system architecture and degradation use method and device | |
US20230343231A1 (en) | Ads-b validation using directional antenna |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: AVIATION COMMUNICATION & SURVEILLANCE SYSTEMS, LLC Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SMITH, MARK DEAN;REEL/FRAME:017249/0101 Effective date: 20051107 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
REMI | Maintenance fee reminder mailed | ||
FPAY | Fee payment |
Year of fee payment: 4 |
|
SULP | Surcharge for late payment | ||
AS | Assignment |
Owner name: L-3 COMMUNICATIONS CORPORATION, NEW YORK Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:AVIATION COMMUNICATION & SURVEILLANCE SYSTEMS, LLC;REEL/FRAME:026602/0031 Effective date: 20110119 |
|
REMI | Maintenance fee reminder mailed | ||
FPAY | Fee payment |
Year of fee payment: 8 |
|
SULP | Surcharge for late payment |
Year of fee payment: 7 |
|
MAFP | Maintenance fee payment |
Free format text: PAYMENT OF MAINTENANCE FEE, 12TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1553); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY Year of fee payment: 12 |
|
AS | Assignment |
Owner name: L3 TECHNOLOGIES, INC., FLORIDA Free format text: CHANGE OF NAME;ASSIGNOR:L-3 COMMUNICATIONS CORPORATION;REEL/FRAME:063595/0019 Effective date: 20161231 |