CN111555827B

CN111555827B - Method and apparatus for detecting air-to-ground links

Info

Publication number: CN111555827B
Application number: CN202010371976.5A
Authority: CN
Inventors: 丁汀; 郑智明; 王闪闪; 全轶青; 陈实; 姜博文
Original assignee: Commercial Aircraft Corp of China Ltd; Shanghai Aircraft Design and Research Institute Commercial Aircraft Corporation of China Ltd
Current assignee: Commercial Aircraft Corp of China Ltd; Shanghai Aircraft Design and Research Institute Commercial Aircraft Corporation of China Ltd
Priority date: 2020-05-06
Filing date: 2020-05-06
Publication date: 2021-09-03
Anticipated expiration: 2040-05-06
Also published as: CN111555827A

Abstract

The invention provides a method for detecting an air-ground link, which comprises the following steps: the method comprises the steps of receiving a Beidou short message through a first air-ground link, receiving an ADS-C message through a second air-ground link, receiving an ACARS message through a third air-ground link, extracting parameters with the same attribute from the three messages respectively, converting the parameters into a first metering value, a second metering value and a third metering value, establishing a time synchronization mechanism, and comparing the first metering value, the second metering value and the third metering value at the same time point to detect whether the first air-ground link, the second air-ground link and the third air-ground link have faults or not. In addition, the invention also provides a device for executing the method. The invention can directly reflect the real-time communication performance of the air-ground link, can simply, directly and integrally judge the correctness of the transmission data of the triple redundant link, saves the labor and the period cost of engineering research and development work, and improves the accuracy of the test judgment result.

Description

Method and apparatus for detecting air-to-ground links

Technical Field

The present invention relates to wireless communications, and more particularly, to a method and apparatus for detecting an air-to-ground link.

Background

Beidou position information, ADS-C (Automatic Dependent Surveillance-control) downlink report and ACARS (Aircraft communication Addressing and Reporting System) position report in the civil large-scale passenger plane provide necessary position information monitoring data for air traffic control, and the monitoring method is carried out in real time. When the airplane flies in the air, the flight parameters such as the longitude and latitude position, the flight altitude and the like of the airplane can be reported to the ground through the Beidou position information, the ADS-C downlink report and the ACARS position report.

The performance of the air-ground link of the Beidou position information, the ADS-C downlink report and the ACARS position report is an important means for guaranteeing flight safety. The performance of the airborne equipment, the ground system, and the overall communication link all affect the reliability of the overall system. For individual devices and systems, the onboard device should comply with corresponding airworthiness regulations and industry specifications, and the ground system should comply with corresponding specifications, which define the performance standards of the device or system. However, the realization of the end-to-end integral functions of Beidou positioning, ADS-C and ACARS position reporting is not only dependent on the equipment performance of the system, but also closely related to the cross-linking working condition of airborne multiple systems and the performance of air-ground links. A simple method is considered to be developed and used for integrally testing the air-ground link of the civil aviation Beidou positioning system, the ADS-C downlink report and the ACARS position report.

At present, for the function test of the air-ground communication link, whether the link is on or off, whether the message transmission is successfully performed and the receipt is received are usually tested for a single link, and for the original information content of the message transmission, the information or the parameters of the receiving end and the transmitting end can be manually compared only under the necessary condition, so as to judge whether the error code exists. This situation limits the thoroughness of real-time testing to a certain extent, limits testing efficiency, and can only detect a single link at the same time.

Accordingly, there is a need in the art for improved methods and apparatus for detecting air-to-ground links.

Disclosure of Invention

This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

The invention aims to detect the air-ground link of the Beidou positioning system of the civil aircraft in real time in the design test and flight processes of the Beidou positioning system.

According to an aspect of the present invention, there is provided a method for detecting an air-ground link, which may include: a. receiving a Beidou short message through a first air-ground link, extracting a first flight parameter from the Beidou short message, and converting the first flight parameter into a first metering value; b. receiving an ADS-C message through a second air-ground link, extracting a second flight parameter from the ADS-C message, and converting the second flight parameter into a second metering value; c. receiving an ACARS message via a third air-to-ground link, extracting a third flight parameter from the ACARS message, and converting the third flight parameter to a third metric value, wherein the first flight parameter, the second flight parameter, and the third flight parameter are parameters of the same attribute and from the same source; d. establishing a time synchronization mechanism to obtain a first metering value, a second metering value and a third metering value corresponding to the same time point; comparing the first, second and third metering values corresponding to the same point in time to detect whether the first, second and third air-ground links are faulty.

According to another aspect of the present invention, there is provided an apparatus for detecting an air-ground link, which may include: the Beidou short message module is used for receiving a Beidou short message through a first air-ground link, extracting a first flight parameter from the Beidou short message, and converting the first flight parameter into a first metering value; the ADS-C message module is used for receiving the ADS-C message through a second air-ground link, extracting a second flight parameter from the ADS-C message and converting the second flight parameter into a second metering value; an ACARS message module for receiving an ACARS message via a third air-to-ground link, extracting a third flight parameter from the ACARS message, and converting the third flight parameter into a third metric value, wherein the first flight parameter, the second flight parameter, and the third flight parameter are parameters of the same attribute and from the same source; the time synchronization module is used for establishing a time synchronization mechanism to obtain a first metering value, a second metering value and a third metering value corresponding to the same time point; and the detection module is used for comparing the first metering value, the second metering value and the third metering value corresponding to the same time point to detect whether the first air-ground link, the second air-ground link and the third air-ground link have faults or not.

According to yet another aspect of the present invention, another apparatus for detecting an air-to-ground link is provided, which may include: a memory; and a processor coupled to the memory, wherein the processor is configured to: receiving a Beidou short message through a first air-ground link, extracting a first flight parameter from the Beidou short message, and converting the first flight parameter into a first metering value; receiving an ADS-C message through a second air-ground link, extracting a second flight parameter from the ADS-C message, and converting the second flight parameter into a second metering value; receiving an ACARS message via a third air-to-ground link, extracting a third flight parameter from the ACARS message, and converting the third flight parameter to a third metric value, wherein the first flight parameter, the second flight parameter, and the third flight parameter are parameters of the same attribute and from the same source; establishing a time synchronization mechanism to obtain a first metering value, a second metering value and a third metering value corresponding to the same time point; and comparing the first, second and third metering values corresponding to the same point in time to detect whether the first, second and third air-ground links have a fault.

According to another aspect of the invention, there is provided a computer readable medium having a computer program stored thereon, the computer program being executable by a processor to perform the steps of: receiving a Beidou short message through a first air-ground link, extracting a first flight parameter from the Beidou short message, and converting the first flight parameter into a first metering value; receiving an ADS-C message through a second air-ground link, extracting a second flight parameter from the ADS-C message, and converting the second flight parameter into a second metering value; receiving an ACARS message via a third air-to-ground link, extracting a third flight parameter from the ACARS message, and converting the third flight parameter to a third metric value, wherein the first flight parameter, the second flight parameter, and the third flight parameter are parameters of the same attribute and from the same source; establishing a time synchronization mechanism to obtain a first metering value, a second metering value and a third metering value corresponding to the same time point; and comparing the first, second and third metering values corresponding to the same point in time to detect whether the first, second and third air-ground links have a fault.

By adopting the method and the device, the real-time communication performance of the Beidou position information communication system can be directly reflected through the difference comparison and analysis of the Beidou position information, the ADS-C information and the ACARS information, the correctness and the completeness of the transmission data of the triple redundant link can be simply, directly and integrally judged, the labor and the period cost of engineering research and development work are saved, the accuracy of a test judgment result is improved, and the economic effect of model engineering is greatly supported.

These and other features and advantages will become apparent upon reading the following detailed description and upon reference to the accompanying drawings. It is to be understood that both the foregoing general description and the following detailed description are explanatory only and are not restrictive of aspects as claimed.

Drawings

So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only some typical aspects of this invention and are therefore not to be considered limiting of its scope, for the description may admit to other equally effective aspects.

Fig. 1 illustrates three air-to-ground links for transmitting beidou short messages, ADS-C messages, and ACRARS messages, respectively, according to one embodiment of the invention.

Fig. 2 illustrates a flow diagram of a method for detecting an air-to-ground link in accordance with one embodiment of the present invention.

Fig. 3 illustrates a block diagram of an apparatus for detecting an air-to-ground link, in accordance with one embodiment of the present invention.

Fig. 4 illustrates a block diagram of an apparatus supporting air-to-ground link detection in accordance with one embodiment of the present invention.

Detailed Description

The present invention will be described in detail below with reference to the attached drawings, and the features of the present invention will be further apparent from the following detailed description.

According to the invention, Beidou position information, ACARS position information and ADS-C position information issued by an airplane are subjected to difference comparison, and the attribute of difference data is judged; a time synchronization trigger mechanism is established through a time synchronizer to ensure the time consistency of the ACARS position information, the ADS-C position information and the Beidou position information. And judging the correctness and the accuracy of the flight parameters of the three redundant links according to the comparison result, thereby detecting the performance of the air-ground link of the system.

Fig. 1 illustrates three air-to-ground links for transmitting beidou short messages, ADS-C messages, and ACRARS messages, respectively, according to one embodiment of the invention. When the aircraft 100 flies in the air, the flight parameters of the aircraft 100, such as the longitude and latitude position, the flight altitude, the airspeed and the like, can be reported to the ground receiving station 120 through the Beidou short message, the ADS-C downlink message and the ACARS downlink message respectively. The three messages may be simultaneously transmitted to ground receiving station 120 over three different air-to-ground links, respectively. For example, the on-board equipment on the aircraft 100 may generate beidou short messages containing various flight parameters and send to the ground receiving station 120 over the first air-to-ground link 130. The first air-to-ground link 130 may include a first portion connecting the aircraft 100 and the beidou satellite 110 and a second portion connecting the beidou satellite 110 and the ground receiving station 120. Thus, the first air-to-ground link 130 may be considered a satellite communication link. In addition, the onboard equipment on the aircraft 100 may generate ADS-C downlink messages containing various flight parameters in accordance with the D0-242 specification and transmit to the ground receiving station 120 via the second air-to-ground link 140. The onboard equipment on the aircraft 100 may also generate ACARS downlink messages containing various flight parameters in accordance with the ARINC618/ARINC620 specification and transmit to the ground receiving station 120 via the third air-to-ground link 150. In one embodiment of the present invention, the second air-ground link 140 and the third air-ground link 150 may be communication links employing Very High Frequency (VHF) communication.

As mentioned above, in the prior art, for the function test of the air-ground communication link, it is usually tested whether the link is on or off, whether the message transmission is successful and the receipt is received for the individual link, and for the original information content of the message transmission, the information or parameters of the receiving end and the sending end can only be manually compared if necessary, so as to determine whether there is an error code. This situation limits the thoroughness of real-time testing to a certain extent, limits testing efficiency, and can only detect a single link at the same time. In the present invention, by comparing the differences of the flight parameters contained in the beidou short message, the ADS-C message and the ACRARS message respectively transmitted through the air-

ground links

130, 140 and 150, the correctness of the data transmission of the air-ground links can be simply and directly judged to determine whether one or more of the air-ground links has a fault.

Fig. 2 illustrates a flow diagram of a method 200 for detecting an air-to-ground link in accordance with one embodiment of the present invention. For example, method 200 may be implemented within at least one processor (e.g., processor 420 of fig. 4), which may be located in a ground station computer system, a remote server, or any other suitable device. Of course, in various aspects of the invention, the method 200 may be implemented by any suitable apparatus capable of performing the relevant operations.

At step 210, the method 200 may include receiving a beidou short message via a first air-to-ground link, extracting a first flight parameter from the beidou short message, and converting the first flight parameter to a first metering value. The first air-ground link may be the first air-ground link 130 shown in fig. 1. The beidou short message may include various flight parameters (e.g., aircraft identification number, aircraft position, altitude, airspeed, etc.) collected by the onboard equipment of the aircraft (e.g., sensors, beidou positioning system receivers, computers, etc.) and the time at which the collection was performed (e.g., a timestamp). In one embodiment, the first flight parameter may be one of an aircraft identification number, an aircraft position, a flight altitude, and an airspeed. The first flight parameter may be converted to a first metric value, and the first metric value corresponds to a timestamp indicative of a time at which the first flight parameter was acquired. For example, when the first flight parameter is an aircraft identification number, the aircraft identification number may be converted to a metric value a 1; when the first flight parameter is aircraft position, the aircraft position may be converted to metric b 1; when the first flight parameter is altitude, the altitude may be converted to a metric c 1; or when the first flight parameter is airspeed, the airspeed may be converted to a metric d 1. In one embodiment, the conversion operation may be implemented by encoding.

At step 220, the method 200 may include receiving an ADS-C message via a second air-to-ground link, extracting a second flight parameter from the ADS-C message, and converting the second flight parameter to a second metric. The second air-ground link may be the second air-ground link 140 shown in fig. 1. The ADS-C message may include various flight parameters (e.g., aircraft identification number, aircraft latitude and longitude position, altitude, airspeed, etc.) collected by the onboard equipment of the aircraft and the time at which the collection was performed (e.g., a timestamp). In one embodiment, the second flight parameter may be one of an aircraft identification number, an aircraft position, a flight altitude, and an airspeed. The second flight parameter may be converted to a second metric value, and the second metric value corresponds to a timestamp indicative of a time at which the second flight parameter was acquired. For example, when the second flight parameter is an aircraft identification number, the aircraft identification number may be converted to a metric value a 2; when the second flight parameter is aircraft position, the aircraft position may be converted to metric b 2; when the second flight parameter is altitude, the altitude may be converted to a metric c 2; or when the second flight parameter is airspeed, the airspeed may be converted to a metric d 2. In one embodiment, the conversion operation may be implemented by encoding.

At step 230, the method 200 may include receiving an ACARS message via a third air-to-ground link, extracting a third flight parameter from the ACARS message, and converting the third flight parameter to a third metric value. The third air-ground link may be the third air-ground link 150 shown in fig. 1. The ACARS message may include various flight parameters (e.g., aircraft identification number, aircraft latitude and longitude position, altitude, airspeed, etc.) collected by an onboard device of the aircraft and the time at which the collection was performed (e.g., a timestamp). In one embodiment, the third flight parameter may be one of an aircraft identification number, an aircraft position, a flight altitude, and an airspeed. The third flight parameter may be converted to a third metric value, and the third metric value corresponds to a timestamp indicating a time at which the third flight parameter was acquired. For example, when the third flight parameter is an aircraft identification number, the aircraft identification number may be converted to a metric value a 3; when the third flight parameter is aircraft position, the aircraft position may be converted to metric b 3; when the third flight parameter is altitude, the altitude may be converted to a metric c 3; or when the third flight parameter is airspeed, the airspeed may be converted to a metric d 3. In one embodiment, the conversion operation may be implemented by encoding.

In the present invention, steps 210, 220 and 230 may be performed simultaneously, and the first, second and third flight parameters are parameters of the same nature and from the same source (e.g., the same sensor). For example, the first, second, and third flight parameters are all aircraft identification numbers, all aircraft positions, all flight altitudes, or all airspeeds. In other words, the first, second, and third metering values correspond to the same flight parameter from the same source transmitted via the three air-to-ground links, respectively.

In an optional step, the first, second and third metering values obtained by

steps

210, 220 and 230 may be stored in a database for subsequent use. The ground transmission of data can adopt local area network and other modes. Alternatively, the first, second and third metering values may not be stored in a database, but used directly in the next processing step.

At step 240, the method 200 may include establishing a time synchronization mechanism to obtain a first metric value, a second metric value, and a third metric value corresponding to the same point in time. The time synchronization mechanism is established in this step to ensure that the first, second and third metering values are equalTime synchronization of the magnitudes. That is, it is ensured that the first, second and third metric values represent the same information meaning and are data sensed by the same on-board sensor at the same time. For example, the first metric value, the second metric value, and the third metric value each represent the aircraft at time t₁The flying height of (a) so that the comparison is comparable. In one embodiment, the time synchronization mechanism may be implemented by time stamps corresponding to the first, second and third metering values, respectively.

Advantageously, the time reference of the time synchronization mechanism in step 240 may be the least common multiple of the time interval of the beidou short message, the time interval of the ADS-C message and the time interval of the ACARS message. In practice, the time intervals for sending the Beidou short message, the ADS-C message and the ACARS message may be different. For example, the sampling interval for the information in the big dipper short message may be 1 second (i.e., flight parameters are acquired once per second), the sampling interval for the information in the ADS-C message may be 2 seconds (i.e., flight parameters are acquired once every 2 seconds), and the sampling interval for the information in the ACARS message may be 4 seconds (i.e., flight parameters are acquired once every 4 seconds). The time reference of the time synchronization mechanism should be the least common multiple of the three, i.e. 4 seconds, so as to ensure that each first measurement value has the corresponding second measurement value and the third measurement value that can be compared, thereby further ensuring the comparability of the first measurement value, the second measurement value and the third measurement value compared in step 250.

Finally, in step 250, the method 200 may include comparing the first, second, and third metric values corresponding to the same point in time to detect whether the first, second, and third air-ground links have a fault. Since the first, second and third metric values corresponding to the same point in time represent the same flight parameter from the same source at the same time, it can be determined that the data difference must come from transmission via different air-to-ground links. Therefore, the real-time transmission performance of each air-ground link can be directly reflected through the difference comparison and analysis of the first metering value, the second metering value and the third metering value. For example, if the first metric value, the second metric value, and the third metric value are the same, it may be determined that none of the first air-to-ground link, the second air-to-ground link, and the third air-to-ground link are faulty. Alternatively, if the first metric value is different from the second metric value and the second metric value is equal to the third metric value, it may be determined that the first air-to-ground link is faulty. If the first metric value is equal to the second metric value and different from the third metric value, it may be determined that the third air-to-ground link is faulty. If the first metric value is equal to the third metric value and different from the second metric value, it may be determined that the second air-to-ground link is faulty. If the first metric value is different from the second metric value and the third metric value and the second metric value is also different from the third metric value, it may be determined that a fault exists with at least two air-to-ground links.

In a preferred embodiment of the present invention, if it is determined through the comparison in step 250 that the first air-ground link, the second air-ground link, and/or the third air-ground link has a failure, a failure report may be displayed via the display module to indicate that the corresponding air-ground link has a failure. For example, if it is determined that the first air-to-ground link has failed, a failure report indicating that the first air-to-ground link has failed may be displayed via the display module. Thus, the staff can know which air-to-ground link(s) is/are faulty and take corresponding measures to resolve the fault. The display module may be, for example, any display device installed at a ground station computer, a remote server, or any other suitable device.

Typically, the movement of the aircraft is a mechanical movement, and this mechanical movement is generally continuous, which means that the first metric values associated with the Beidou short messages should be continuous, the second metric values associated with the ADS-C messages should be continuous, and the third metric values associated with the ACARS messages should also be continuous. In practice, due to the influence of the environment factor of the burst (e.g., the environment noise of the burst, etc.), interference may be generated on data transmission, thereby causing inaccuracy of the data received within a certain period of time. In the present invention, the variation curve (i.e., the first fitted curve) may be obtained by, for example, fitting a plurality of first metric values, and the first metric values deviating from the variation curve are regarded as singular points and are not used for the comparison in step 250. Similarly, the second fitted curve and the third fitted curve may be obtained by fitting the plurality of second metric values and the plurality of third metric values, respectively. In one embodiment, the fitting operation may employ a quadratic or cubic fitting method. The quadratic fitting and cubic fitting method is simple and easy to implement, and simultaneously, the necessary fitting precision requirement is also ensured. After the first fitted curve, the second fitted curve, and the third fitted curve are obtained, first, second, and third metric values corresponding to the same time point on the first, second, and third fitted curves may be obtained, and the corresponding three air-ground links may be detected by comparing the first, second, and third metric values. In this way, the difference due to the non-air-ground link itself can be eliminated, so that the performance of the air-ground link can be detected more accurately.

In a preferred embodiment of the present invention, the states of the first fitted curve, the second fitted curve, and the third fitted curve may be displayed and the detection result may be displayed through a display module. The display module may be, for example, any display device installed at a ground station computer, a remote server, or any other suitable device. Displaying the detection result may include displaying a conclusive error prompt (e.g., displaying an error prompt indicating that a particular air-to-ground link has a failure when the particular air-to-ground link has been detected to have a failure).

Fig. 3 is a block diagram of an apparatus 300 for detecting an air-to-ground link according to one embodiment of the invention. All of the functional blocks of the apparatus 300 (including the respective units in the apparatus 300) may be implemented by hardware, software, or a combination of hardware and software. Those skilled in the art will appreciate that the functional modules depicted in fig. 3 may be combined into a single functional block or divided into multiple sub-functional blocks.

The device 300 may include a beidou short message module 310, an ADS-C message module 320, an ACARS message module 330, a time synchronization module 340, and a detection module 350. Each of these components may be in communication with each other (e.g., via one or more buses).

The beidou short message module 310 may be configured to receive a beidou short message via the first air-to-ground link, extract a first flight parameter from the beidou short message, and convert the first flight parameter into a first metering value.

The ADS-C message module 320 may be configured to receive the ADS-C message via the second air-to-ground link, extract a second flight parameter from the ADS-C message, and convert the second flight parameter into a second metric.

The ACARS module 330 may be configured to receive an ACARS message via a third air-to-ground link, extract a third flight parameter from the ACARS message, and convert the third flight parameter to a third metric value. The first, second and third flight parameters are parameters of the same nature and are from the same source.

The time synchronization module 340 may be used to establish a time synchronization mechanism to obtain the first, second, and third metering values corresponding to the same point in time.

The detection module 350 may be configured to compare the first, second, and third metric values corresponding to the same point in time to detect whether the first, second, and third air-ground links have a fault.

Moreover, the apparatus 300 may also optionally include a fitting module for respectively fitting a plurality of first metric values associated with the plurality of beidou short messages, a plurality of second metric values associated with the plurality of ADS-C messages, and a plurality of third metric values associated with the plurality of ACARS messages to obtain a first fitted curve, a second fitted curve, and a third fitted curve. The apparatus 300 may further optionally include a display module for displaying the first fit curve, the second fit curve, and the third fit curve, the detection results, and/or the fault report.

Fig. 4 illustrates a block diagram of an apparatus 400 that supports air-to-ground link detection in accordance with one embodiment of the present invention. The apparatus 400 may include a processor 420, a memory 425, software 430, and a transceiver 435. It should be noted that the apparatus 400 may also include other components not shown. The above components may be in electronic communication via one or more buses, such as bus 410. Processor 420 may include intelligent hardware devices (e.g., a general purpose processor, a Digital Signal Processor (DSP), a Central Processing Unit (CPU), a microcontroller, an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), a programmable logic device, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, processor 420 may be configured to operate a memory array using a memory controller. In other cases, the memory controller may be integrated into the processor 420. Processor 420 may be configured to execute computer programs stored in memory to perform various functions (e.g., functions or tasks to support air-to-ground link detection). Memory 425 may include computer readable media including, but not limited to, Random Access Memory (RAM) and Read Only Memory (ROM). The memory 425 may store computer-readable, computer-executable software 430 including instructions that, when executed, cause the processor to perform various functions described herein. The software 430 may include code for implementing aspects of the present disclosure, including code for supporting air-to-ground link detection. The transceiver 435 may communicate with the aircraft 100 and the beidou satellite 110 (e.g., receiving beidou short messages from the beidou satellite 110, ADS-C messages from the aircraft 100, and/or ACARS messages from the aircraft 100).

Although the various aspects of the present invention have been described thus far with reference to the accompanying drawings, the above-described methods, systems, and apparatuses are merely examples, and the scope of the present invention is not limited to these aspects but only by the appended claims and equivalents thereof. Various components may be omitted or may be replaced with equivalent components. In addition, the steps may also be performed in a different order than described in the present invention. Further, the various components may be combined in various ways. It is also important that as technology develops that many of the described components can be replaced by equivalent components appearing later. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for detecting an air-to-ground link, the method comprising:

a. receiving a Beidou short message through a first air-ground link, extracting a first flight parameter from the Beidou short message, and converting the first flight parameter into a first metering value;

b. receiving a contract-based automatic dependent surveillance (ADS-C) message via a second air-ground link, extracting a second flight parameter from the ADS-C message, and converting the second flight parameter into a second metering value;

c. receiving an aircraft communication addressing and reporting system, ACARS, message via a third air-to-ground link, extracting a third flight parameter from the ACARS message, and converting the third flight parameter to a third metric value, wherein the first flight parameter, the second flight parameter, and the third flight parameter are parameters of the same attribute and from the same source;

d. establishing a time synchronization mechanism to obtain the first, second, and third metering values corresponding to a same point in time; and

e. comparing the first, second, and third metering values corresponding to the same point in time to detect whether the first, second, and third air-ground links are faulty, wherein for the first, second, and third metering values corresponding to the same point in time, it is determined that the first air-ground link is faulty if the first metering value is different from the second metering value and the second metering value is equal to the third metering value.

2. The method of claim 1, wherein step e further comprises: if the first, second, and third metric values corresponding to the same point in time are the same, then none of the first, second, and third air-to-ground links fail.

3. The method of claim 1, wherein a time reference of the time synchronization mechanism is a least common multiple of a time interval of the Beidou short messages, a time interval of the ADS-C messages, and a time interval of the ACARS messages.

4. The method of claim 1, wherein the parameter of the same attribute comprises one of:

identifying the airplane;

an aircraft position;

a flying height; and

space velocity.

5. The method of claim 1, wherein the method further comprises:

if the first air-to-ground link, the second air-to-ground link, and/or the third air-to-ground link fails, a failure report is displayed via a display module to indicate that the respective air-to-ground link failed.

6. The method of claim 1, wherein the method further comprises, prior to step d: fitting a plurality of first metering values associated with a plurality of Beidou short messages, a plurality of second metering values associated with a plurality of ADS-C messages and a plurality of third metering values associated with a plurality of ACARS messages respectively to obtain a first fitting curve, a second fitting curve and a third fitting curve;

and wherein said step d further comprises: obtaining the first, second, and third metrology values on the first, second, and third fitted curves corresponding to the same time point.

7. The method of claim 6, wherein said fitting is a quadratic or cubic fitting method.

8. The method of claim 6, wherein the first fit curve, the second fit curve, and the third fit curve are displayed via a display module, and wherein detection results are displayed via the display module.

9. An apparatus for detecting an air-to-ground link, the apparatus comprising:

the Beidou short message module is used for receiving a Beidou short message through a first air-ground link, extracting a first flight parameter from the Beidou short message, and converting the first flight parameter into a first metering value;

the contract type automatic dependent surveillance ADS-C message module is used for receiving the ADS-C message through a second air-ground link, extracting a second flight parameter from the ADS-C message and converting the second flight parameter into a second metering value;

an aircraft communication addressing and reporting system, ACARS, message module to receive an ACARS message via a third air-to-ground link, extract a third flight parameter from the ACARS message, and convert the third flight parameter to a third metric value, wherein the first flight parameter, the second flight parameter, and the third flight parameter are parameters of the same attribute and from the same source;

a time synchronization module for establishing a time synchronization mechanism to obtain the first, second and third metering values corresponding to the same time point; and

a detection module to compare the first, second, and third metering values corresponding to a same point in time to detect whether a fault exists with the first, second, and third air-ground links, wherein for the first, second, and third metering values corresponding to a same point in time, it is determined that a fault exists with the first air-ground link if the first metering value is different from the second metering value and the second metering value is equal to the third metering value.

10. An apparatus for detecting an air-to-ground link, the apparatus comprising:

a memory; and

a processor coupled to the memory, wherein the processor is configured to:

receiving a Beidou short message through a first air-ground link, extracting a first flight parameter from the Beidou short message, and converting the first flight parameter into a first metering value;

receiving a contract-based automatic dependent surveillance (ADS-C) message via a second air-ground link, extracting a second flight parameter from the ADS-C message, and converting the second flight parameter into a second metering value;

receiving an aircraft communication addressing and reporting system, ACARS, message via a third air-to-ground link, extracting a third flight parameter from the ACARS message, and converting the third flight parameter to a third metric value, wherein the first flight parameter, the second flight parameter, and the third flight parameter are parameters of the same attribute and from the same source;

establishing a time synchronization mechanism to obtain the first, second, and third metering values corresponding to a same point in time; and

comparing the first, second, and third metering values corresponding to the same point in time to detect whether the first, second, and third air-ground links are faulty, wherein for the first, second, and third metering values corresponding to the same point in time, it is determined that the first air-ground link is faulty if the first metering value is different from the second metering value and the second metering value is equal to the third metering value.

11. A computer-readable medium having a computer program stored thereon, the computer program being executable by a processor to perform the steps of: