Navigation precision test method and system of L-band digital aviation communication system, medium and computer program product

Abstract

The invention provides a navigation precision test method and system of an L-band digital aviation communication system, a medium and a computer program product, relates to the field of civil aviation communication, and solves the limitation problems of high cost, low efficiency, potential safety hazards, complex equipment and the like of the existing test method. The method comprises the following steps: establishing a navigation precision test environment of an L-DACS1 airborne terminal, and presetting flight path data of a virtual aircraft; presetting ground position data, setting signal propagation parameters, and transmitting navigation information to the L-DACS1 airborne terminal through the channel simulator according to the ground position data in combination with the flight path data and the ground-air signal propagation parameters; the L-DACS1 airborne terminal performs navigation calculation and then outputs navigation positioning data, the navigation positioning data is compared with preset flight path data, and the navigation precision of the L-DACS1 airborne terminal is evaluated through a navigation error; according to the invention, navigation precision testing can be smoothly completed in a laboratory environment.

Description

Technical Field

[0001] The present invention relates to the field of civil aviation communication, and particularly to a navigation accuracy testing method, system, medium and computer program product for an L-band digital aeronautical communication system. Background Art

[0002] The next-generation ground-air broadband wireless communication technology, as an innovative direction in the field of aeronautical communication, especially the solution based on the orthogonal frequency division multiplexing (OFDM) technology, has been widely studied in this field. The basic principle of this technology is to build a stable ground-air communication link for radio signals transmitted to the air through ground cellular base stations deployed on flight routes or specific airspaces, so as to provide high-rate and large-bandwidth communication services for aircraft. This innovation not only supports the communication needs of passengers in the cabin of civil airliners such as voice calls and Internet access, but also paves the way for a new generation of modern air traffic management information services, and is an indispensable part of realizing the sky-ground integrated communication network.

[0003] The L-band Digital Aeronautical Communication System (L-DACS), as a highly regarded alternative system for the ground-air data link, aims to meet the stringent requirements of future aeronautical mobile communications. The L-DACS system includes L-DACS1 and L-DACS2; the L-DACS1 system is based on the frequency division duplex (FDD) technology of OFDM and operates in the aeronautical L-band from 960 MHz to 1164 MHz. With its excellent transmission capacity, high spectral efficiency and multi-carrier transmission ability adapted to the aeronautical mobile channel, the L-DACS1 system is an important ground-air broadband communication data link in the future communication infrastructure framework, and is also the first system certified by the International Civil Aviation Organization (ICAO) to truly realize the integration of communication, navigation and surveillance, and has been listed as the preferred solution for aeronautical communication systems in the next two decades and beyond.

[0004] However, whether the navigation accuracy of the L-DACS1 system can meet the relevant requirements of ICAO needs to be confirmed through strict testing and verification. Currently, the traditional method for testing the navigation accuracy of the L-DACS1 system is to deploy ground base stations on a preset flight path and conduct actual flight tests using the airborne terminals carried by aircraft. This method has the following significant disadvantages:

[0005] 1. High cost: Each flight test requires a large amount of resources, including manpower, material resources and financial resources, resulting in high testing costs.

[0006] 2. Low efficiency: Since the testing process depends on actual flights, it is restricted by various factors such as weather, airspace availability and flight scheduling, resulting in low testing efficiency.

[0007] 3. Safety Considerations: Actual flight tests may face flight safety risks, especially when the test system is not yet fully mature.

[0008] Therefore, there is an urgent need for a new test method to effectively reduce test costs, improve test efficiency, ensure safety during the test, accurately evaluate the navigation accuracy of the L-DACS1 system, and ensure its compliance with the ICAO standard requirements. Summary of the Invention

[0009] Based on the current situation in the background art, the object of the present invention is to solve the limitations of the existing test methods, such as high cost, low efficiency, potential safety hazards, and complex equipment. Therefore, a navigation accuracy test method, system, medium, and computer program product for an L-band digital avionics communication system are proposed. The present invention can complete the navigation accuracy test in a laboratory environment, with short time consumption and strong practicability, providing a research basis and data support for the subsequent development of equipment, thus reducing the development cost and cycle of the equipment and promoting the research and development process of the domestic L-DACS1 system with independent intellectual property rights and high reliability.

[0010] The present invention adopts the following technical solutions to achieve the object:

[0011] A navigation accuracy test method for an L-band digital avionics communication system, the method comprising the following steps:

[0012] S1. Based on a channel simulator, build a navigation accuracy test environment for the L-DACS1 airborne terminal;

[0013] S2. Preset the flight trajectory data of a virtual aircraft and input it into the channel simulator;

[0014] S3. Preset multiple ground position data and input it into the channel simulator, and set the signal propagation parameters in the channel simulator at the same time;

[0015] S4. For each ground position data, combine the flight trajectory data of the virtual aircraft at the current moment with the ground-air signal propagation parameters, and transmit navigation information to the L-DACS1 airborne terminal through the channel simulator;

[0016] S5. The L-DACS1 airborne terminal receives the navigation information, performs navigation calculations, and outputs navigation positioning data;

[0017] S6. Compare the navigation positioning data output by the L-DACS1 airborne terminal with the preset flight trajectory data in the channel simulator to determine the navigation error; evaluate the navigation accuracy of the L-DACS1 airborne terminal through the navigation error.

[0018] Specifically, in step S1, the navigation accuracy test environment consists of a channel simulator, the L-DACS1 airborne terminal under test, and multiple L-DACS1 ground base stations; each L-DACS1 ground base station is equipped with a computer for simulation to preset ground position data and transmit the data to the channel simulator; the L-DACS1 airborne terminal is used to receive the navigation information generated after being processed by the channel simulator under simulation conditions and perform navigation calculations; the channel simulator is used to simulate the real environment of ground-air propagation by setting signal propagation parameters and transmit the generated navigation information to the L-DACS1 airborne terminal.

[0019] Specifically, in step S2, the channel simulator is equipped with a computer for simulation. After presetting and generating the flight trajectory data of the virtual aircraft through computer software, it is input into the channel simulator; the preset flight trajectory data includes position information, speed information, direction and attitude information, and time information.

[0020] Preferably, in step S3, a total of 4 ground position data are preset, corresponding to 4 different L-DACS1 ground base stations; the geographical coordinates of each L-DACS1 ground base station are preset and the base station antenna direction corresponding to the geographical coordinates is configured. After the presetting and configuration are completed, the relevant data are imported into the channel simulator.

[0021] Specifically, the model of the channel simulator is Spirent Vertex; when importing the preset 4 ground position data into this model of channel simulator, the 3D Geometric Channel Model Setting function is enabled, and the geographical coordinates and base station antenna direction of each L-DACS1 ground base station are imported in sequence; after the signal propagation parameters are set, the channel mode of this model of channel simulator is set to SISO, and the A→B and B→A options presented on the interactive page are selected to enable the channel two-way communication function.

[0022] Specifically, in step S3, according to the requirements of the ground-air signal propagation environment required for the test, the categories of the set signal propagation parameters include path loss, multipath effect, and Doppler frequency shift.

[0023] Preferably, in step S4, before transmitting the navigation information to the L-DACS1 airborne terminal, the carrier power and frequency of the transmitted signal are synchronously adjusted through the computer for simulation equipped with the channel simulator to make it consistent with the output signals of multiple L-DACS1 ground base stations transmitting ground position data.

[0024] The present invention also provides a computer device system, including a memory, a processor, and a computer program stored on the memory. The processor executes the computer program to implement the steps of the navigation accuracy test method for the foregoing L-band digital aviation communication system.

[0025] The present invention also provides a computer-readable storage medium, on which a computer program / instructions are stored. When the computer program / instructions are executed by a processor, the steps of the navigation accuracy test method for the foregoing L-band digital aviation communication system are implemented.

[0026] The present invention also provides a computer program product, including a computer program / instructions. When the computer program / instructions are executed by a processor, the steps of the navigation accuracy test method for the foregoing L-band digital aviation communication system are implemented.

[0027] In summary, due to the adoption of the present technical solution, the beneficial effects of the present invention are as follows:

[0028] By using a channel simulator, the present invention can accurately simulate the ground-air data propagation environment in the real world. Only by adjusting the parameters of the channel simulator can the propagation conditions be quickly switched, so as to comprehensively and accurately evaluate the navigation performance of the L-DACS1 airborne terminal in a complex environment. This method greatly improves the flexibility and efficiency of the test and avoids the delays caused by environmental factors in traditional flight tests.

[0029] Traditional test methods usually require the aircraft to conduct actual flights, and the cost of each test can be as high as hundreds of thousands of yuan. In contrast, the present invention can complete the test in a laboratory environment, only using standard computers and supporting electronic instruments, and there are mature products available in the market for these devices. Therefore, the present invention can significantly reduce the investment in manpower, material resources, and financial resources, and greatly reduce the overall cost of the test.

[0030] Based on the mature theories of flight trajectory modeling and channel parameter setting, the present invention ensures the effectiveness and reliability of the test method. Under laboratory conditions, by generating and importing specific flight trajectories and base station coordinates, the relative position relationship between the aircraft and the L-DACS1 ground base station can be accurately reproduced, making the test results closer to the actual situation and improving the accuracy and authenticity of the test.

[0031] Through the efficient test method of the present invention, the R & D team can quickly obtain a large amount of effective test data, providing strong support for the optimization and iteration of subsequent equipment. This not only shortens the R & D cycle of related equipment but also speeds up the transformation from prototype to commercialization, contributing to the popularization and application of the L-DACS1 system in the field of aviation communication. Description of the Drawings

[0032] Figure 1 It is a schematic diagram of the overall process of the method of the present invention;

[0033] Figure 2 It is a schematic diagram of the navigation accuracy test architecture of the embodiment of the present invention;

[0034] Figure 3 It is a schematic diagram of the connection between the channel simulator and the computer;

[0035] Figure 4 It is a schematic diagram of the interface for the channel simulator to import ground base station information;

[0036] Figure 5 It is a schematic diagram of the channel mode selection interface of the channel simulator;

[0037] Figure 6 It is a schematic diagram of the setting interface for the signal propagation parameters of the channel simulator;

[0038] Figure 7 It is a schematic diagram of the setting interface for the carrier power and frequency of the channel simulator. Detailed implementation manners

[0039] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated herein can be arranged and designed in various different configurations.

[0040] Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0041] Embodiment 1

[0042] As Figure 1 shown, a method for testing the navigation accuracy of an L-band digital aeronautical communication system, the overall steps of the method can be summarized as follows:

[0043] S1. Based on the channel simulator, build a navigation accuracy test environment for the L-DACS1 airborne terminal;

[0044] S2. Preset the flight trajectory data of the virtual aircraft and input it into the channel simulator;

[0045] S3. Preset multiple ground position data and input it into the channel simulator, and at the same time set the signal propagation parameters in the channel simulator;

[0046] S4. For each ground position data, in combination with the flight trajectory data of the virtual aircraft at the current moment and the ground-air signal propagation parameters, the navigation information is transmitted to the L-DACS1 airborne terminal through the channel simulator.

[0047] S5. The L-DACS1 airborne terminal receives the navigation information, performs navigation calculations, and outputs navigation positioning data.

[0048] S6. Compare the navigation positioning data output by the L-DACS1 airborne terminal with the preset flight trajectory data in the channel simulator to determine the navigation error; evaluate the navigation accuracy of the L-DACS1 airborne terminal through the navigation error.

[0049] In this embodiment, the details of each step will be specifically introduced in the order of the above steps.

[0050] Generally speaking, this embodiment will use 4 L-DACS1 ground base stations as signal sources, as shown in Figure 2 , simulate the propagation process of the transmitted signal in the real ground-air environment through the channel simulator, and then input the signal to the L-DACS1 airborne terminal under test; after the L-DACS1 airborne terminal calculates the positioning information, compare it with the preset data to achieve the test of the navigation accuracy.

[0051] In step S1 of this embodiment, the navigation accuracy test environment consists of a channel simulator, the L-DACS1 airborne terminal under test, and 4 L-DACS1 ground base stations; each L-DACS1 ground base station is equipped with a computer for simulation, which is used to preset the ground position data and transmit the data to the channel simulator; the L-DACS1 airborne terminal is used to receive the navigation information generated after being processed by the channel simulator under the simulation conditions and perform navigation calculations; the channel simulator is used to simulate the real environment of ground-air propagation by setting signal propagation parameters and transmit the generated navigation information to the L-DACS1 airborne terminal.

[0052] In step S2 of this embodiment, the channel simulator is equipped with a computer for simulation. After presetting and generating the flight trajectory data of the virtual aircraft through computer software, it is input into the channel simulator. As shown in Figure 3 , the connection between the channel simulator and the computer can be converted through a USB-RS232 / RJ45 cable.

[0053] The preset flight trajectory data includes position information, speed information, direction and attitude information, and time information. The position information includes longitude and latitude coordinates, which are precise geographical locations and usually the WGS84 coordinate system can be used; altitude, which can be the height relative to sea level or the ground; geographical reference points, including the coordinates of key positions such as the starting point, waypoints, and end point. The speed information includes true airspeed, that is, the speed of the aircraft relative to the air under windless conditions; ground speed, the actual moving speed of the aircraft relative to the ground, taking into account the influence of wind; vertical speed, the rate of climb or descent of the aircraft. The direction and attitude information may include content such as heading angle, pitch angle, roll angle, and yaw angle. The time information involves flight timestamps, which are used to record the time of each data point in the flight trajectory and can be synchronized with other systems; the duration of specific flight phases, such as takeoff, landing, etc.

[0054] In step S3 of this embodiment, a total of 4 ground position data are preset, corresponding to 4 different L-DACS1 ground base stations; for each L-DACS1 ground base station, its own geographical coordinates are preset and the base station antenna direction corresponding to the geographical coordinates is configured. After the presetting and configuration are completed, the relevant data is imported into the channel simulator.

[0055] Here, the 4 different preset L-DACS1 ground base stations may cover different regions, such as cities, mountains, oceans, etc., in order to test the navigation and communication effects in different geographical environments. After the geographical coordinates are determined, when configuring the base station antenna direction, it involves the azimuth angle (horizontal direction) and elevation angle (vertical direction) of the antenna to ensure that the antenna can correctly align with the target area. At the same time, parameters such as the gain and beam width of the antenna are comprehensively considered and preset to simulate various test environments. The interface for presetting and importing the relevant information of the ground base station into the channel simulator can be seen Figure 4 in the schematic diagram.

[0056] In this embodiment, the model of the channel simulator is Spirent Vertex. Spirent Vertex is a high-performance channel simulator manufactured by Spirent Communications. It is designed to simulate complex wireless communication scenarios in a laboratory environment to help verify and optimize the performance of wireless devices and systems. At the same time, the parameter setting function of this channel simulator also supports the requirements of the application scenario of this embodiment.

[0057] When importing the preset 4 ground position data into this model of channel simulator, the 3D Geometric Channel Model Setting function is enabled, and the geographical coordinates and base station antenna directions of each L-DACS1 ground base station are imported in sequence. After the setting of the signal propagation parameters is completed, such as Figure 5As shown, set the channel mode of the channel simulator of this model to SISO, and check the A→B and B→A options presented on the interaction page to enable the channel two-way communication function.

[0058] Also in step S3, according to the requirements of the ground-air signal propagation environment needed for testing, the categories of signal propagation parameters set include path loss, multipath effect, and Doppler shift. Ground-air signal communication is a typical wireless communication. In the process from the transmitter to the receiver, various physical phenomena will be experienced. The simulation of this embodiment simulates it through a channel simulator to evaluate and optimize the performance of the terminal in actual deployment.

[0059] Among them, path loss refers to the phenomenon that the signal naturally attenuates as the distance increases when propagating in free space. In long-distance communication, the signal strength decreases with the square of the distance because the energy is evenly dispersed in the spherical expansion. Path loss can be divided into: free space path loss, which only considers the influence of distance and frequency and does not consider any obstacles or terrain factors; atmospheric absorption: in some frequency bands, especially millimeter waves and higher frequency bands, water vapor and oxygen molecules in the atmosphere will absorb the energy of electromagnetic waves, resulting in additional attenuation; shadow fading caused by obstacles: if there are obstacles between the ground-air signals, it will block the signal propagation and cause a significant decrease in signal strength. The signal propagation parameters of this category can be well set in the channel simulator and reflect the real situation.

[0060] The multipath effect means that when the signal reaches the receiver, in addition to the direct path, there are multiple reflection, refraction, and scattering paths. The signals of each path will have different time delays and phases. When they are superimposed, constructive or destructive interference will occur, resulting in signal strength fluctuations. This phenomenon is particularly obvious in urban environments because buildings and streets will become signal reflectors. By simulating the multipath effect through a channel simulator, the robustness and bit error rate performance of the L-DACS1 airborne terminal in the face of complex environments can be effectively tested, thereby reflecting its navigation performance and evaluating the effectiveness of its own antenna design and signal processing algorithms.

[0061] Doppler shift is a common phenomenon in mobile communication. When the transmitter or receiver moves relative to each other, the received signal frequency will change. The faster the moving speed, the greater the frequency shift. This will cause the offset of the carrier frequency and affect the modulation and demodulation process. The reason for simulating the Doppler shift is to test the performance of the L-DACS1 airborne terminal in a dynamic environment and test the frequency synchronization ability and data transmission stability in ground-air communication. In the test, by changing the settings of the signal propagation parameters, different scenarios can be created to comprehensively evaluate the navigation accuracy of the L-DACS1 airborne terminal. The setting interface of the signal propagation parameters can refer to Figure 6 the schematic diagram.

[0062] In step S4 of this embodiment, as Figure 7 shown, before transmitting navigation information to the L-DACS1 airborne terminal, the carrier power and frequency of the transmitted signal are synchronously adjusted through a computer assigned to the channel simulator for simulation, so that they are consistent with the output signals of 4 L-DACS1 ground base stations transmitting ground position data. Among them, adjusting the power of the transmitted signal is to compensate for propagation loss and ensure sufficient signal strength at the receiving end; ensuring the same operating frequency between the airborne terminal and the ground base station can avoid demodulation errors or synchronization failures caused by frequency offset.

[0063] After all the above details are completed, the output end of the channel simulator can be connected to the signal receiving interface of the L-DACS1 airborne terminal. After ensuring that all connections are correct, the simulation test process can be carried out, and steps S5 and S6 are executed. In step S6, the navigation error can cover position error, speed error, and time error. These error values can help determine the navigation positioning accuracy and stability of the L-DACS1 airborne terminal. Therefore, according to the navigation error, the navigation accuracy of the L-DACS1 airborne terminal can be effectively evaluated. Usually, a threshold can be set in the evaluation process. If the navigation error is within this threshold, it is considered that the terminal meets the accuracy requirements. The method of this embodiment can continuously reproduce the test process of different situations in the laboratory, so as to efficiently achieve the navigation accuracy test of the L-DACS1 airborne terminal.

[0064] In summary, the navigation accuracy test method of the L-band digital aviation communication system proposed by the present invention realizes a significant improvement in test efficiency, a remarkable reduction in cost, and an enhancement in test accuracy through the comprehensive application of the channel simulator in the laboratory environment, providing strong technical support for the research and development and optimization of the L-DACS1 system.

[0065] Embodiment 2

[0066] Based on Embodiment 1, this embodiment provides a computer device system, including a memory, a processor, and a computer program stored on the memory. The processor executes the computer program to implement the steps of the navigation accuracy test method of the L-band digital aviation communication system described in Embodiment 1.

[0067] This embodiment also provides a computer-readable storage medium, on which a computer program / instructions are stored. When the computer program / instructions are executed by the processor, the steps of the navigation accuracy test method of the L-band digital aviation communication system described in Embodiment 1 are implemented.

[0068] This embodiment also provides a computer program product, including computer programs / instructions, which, when executed by a processor, implement the steps of the navigation accuracy test method of the L-band digital avionics communication system described in Embodiment 1.

[0069] In this embodiment, these computer programs / instructions can be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory produce a manufactured article including an instruction device that implements the functions specified in one or more steps of the method.

Claims

1. A navigation accuracy test method for an L-band digital aviation communication system, characterized in that: The method comprises the following steps: S1. Build the navigation accuracy test environment of L-DACS1 airborne terminal based on the channel simulator; S2, presetting the flight trajectory data of the virtual aircraft and inputting it into the channel simulator; S3, presetting a plurality of ground position data and inputting them into a channel simulator, and setting signal propagation parameters in the channel simulator; S4. For each ground position data, combined with the flight trajectory data of the virtual aircraft at the current moment and the ground-to-air signal propagation parameters, the navigation information is transmitted to the L-DACS1 airborne terminal through the channel simulator; S5, L-DACS1 airborne terminal receives navigation information, performs navigation calculations and outputs navigation positioning data; S6. Compare the navigation positioning data output by the L-DACS1 airborne terminal with the flight trajectory data preset in the channel simulator to determine the navigation error; and evaluate the navigation accuracy of the L-DACS1 airborne terminal through the navigation error.

2. The navigation accuracy test method of the L-band digital aviation communication system according to claim 1, characterized in that: In step S1, the navigation accuracy test environment is composed of a channel simulator, a L-DACS1 airborne terminal to be tested, and a plurality of L-DACS1 ground base stations; each L-DACS1 ground base station is equipped with a computer for simulation, which is used to preset ground position data and transmit the data to the channel simulator; the L-DACS1 airborne terminal is used to receive the navigation information generated after being processed by the channel simulator under simulation conditions and perform navigation calculations; The channel simulator is used to simulate the real environment of ground-to-air propagation by setting signal propagation parameters, and transmit the processed navigation information to the L-DACS1 airborne terminal.

3. The navigation accuracy test method of the L-band digital aviation communication system according to claim 1, characterized in that: In step S2, the channel simulator is equipped with a computer for simulation. After the flight trajectory data of the virtual aircraft is preset and generated by computer software, it is input into the channel simulator; the preset flight trajectory data includes position information, speed information, direction and attitude information, and time information.

4. The navigation accuracy test method of the L-band digital aviation communication system according to claim 2, characterized in that: In step S3, a total of 4 ground location data are preset, corresponding to 4 different L-DACS1 ground base stations; the geographical coordinates of each L-DACS1 ground base station are preset and the base station antenna direction corresponding to the geographical coordinates is configured. After the preset and configuration are completed, the relevant data is imported into the channel simulator.

5. The navigation accuracy test method of the L-band digital aviation communication system according to claim 4, characterized in that: The model of the channel simulator is Spirent Vertex; when importing the preset 4 ground location data into this model of channel simulator, enable the 3D Geometric Channel Model Setting function, and import the geographical coordinates and base station antenna direction of each L-DACS1 ground base station in turn; after the signal propagation parameters are set, set the channel mode of this model of channel simulator to SISO, and check the A→B, B→A options presented on the interactive page to enable the channel two-way communication function.

6. The navigation accuracy test method of the L-band digital aviation communication system according to claim 1, characterized in that: In step S3, according to the ground-to-air signal propagation environment requirements for the test, the types of signal propagation parameters set include path loss, multipath effect and Doppler frequency shift.

7. The navigation accuracy test method of the L-band digital aviation communication system according to claim 2, characterized in that: In step S4, before transmitting navigation information to the L-DACS1 airborne terminal, the carrier power and frequency of the transmitted signal are synchronously adjusted through a computer used for simulation assigned to a channel simulator to make it consistent with the output signals of ground position data transmitted by multiple L-DACS1 ground base stations.

8. A computer device system, comprising a memory, a processor and a computer program stored in the memory, characterized in that: The processor executes the computer program to implement the steps of the navigation accuracy test method for the L-band digital aviation communication system as described in any one of claims 1-7.

9. A computer-readable storage medium having a computer program / instruction stored thereon, characterized in that: When the computer program / instruction is executed by a processor, the steps of the navigation accuracy test method of the L-band digital aviation communication system described in any one of claims 1-7 are implemented.

10. A computer program product comprising a computer program / instructions, characterized in that: When the computer program / instruction is executed by a processor, the steps of the navigation accuracy test method of the L-band digital aviation communication system described in any one of claims 1-7 are implemented.

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