A test method for navigation enhancement system

Abstract

An embodiment of the present invention discloses a testing method for a navigation enhancement system, which is characterized by including: S10: performing interface matching testing and functional and performance index testing on a navigation enhancement payload device, a satellite-borne navigation monitoring receiver, and a satellite-borne rubidium clock; S20: performing testing on a navigation enhancement terminal; S30: synchronizing the time of the navigation enhancement payload device, the satellite-borne navigation monitoring receiver, the navigation enhancement terminal, the channel simulator, and the navigation data center; S40: performing interface, functional, performance, and full-process testing on the navigation enhancement payload device, the ground-based navigation enhancement terminal, the navigation data center, the navigation signal simulator, and the channel simulator to verify the correctness of the navigation enhancement system signal and information link design, signal generation, and data processing.

Description

Technical Field

[0001] The present invention relates to the field of low-orbit satellites, and more specifically, to a testing method for a navigation enhancement system. Background Art

[0002] With the rapid development of low-orbit satellite internet constellations, navigation augmentation based on low-orbit satellites (LEO) has become a research hotspot. LEO navigation augmentation systems can enhance the positioning accuracy of high-orbit navigation satellites. They can also serve as space-based monitoring stations to monitor the signal integrity of medium- and high-orbit navigation satellites, improving the accuracy of satellite orbit determination and clock error estimation. LEO satellites, due to their low orbital altitude, easily enhance signals to the Earth, improving positioning in interference, obstruction, and complex environments. This LEO navigation augmentation system can also serve as a backup navigation positioning and timing method when medium- and high-orbit navigation satellites are interfered with or denied.

[0003] The simulation verification system is a key link in verifying the rationality of the low-orbit navigation augmentation system design. However, how to verify the correctness of the signal and information flow between the low-orbit navigation augmentation satellite and ground equipment, test and verify the functions and performance of the on-board payload, and conduct closed-loop simulation verification of the positioning accuracy and backup navigation capabilities that the entire low-orbit navigation augmentation system can achieve are still issues to be solved. Summary of the Invention

[0004] In view of this, a first embodiment of the present invention provides a method for testing a navigation enhancement system, comprising:

[0005] S10: Conduct interface matching test and function and performance index test on navigation enhancement payload, onboard navigation monitoring receiver and onboard rubidium clock;

[0006] S20: Navigation enhancement terminal for testing;

[0007] S30: Synchronizing the time of the navigation enhancement payload device, the onboard navigation monitoring receiver, the navigation enhancement terminal, the channel simulator and the navigation data center;

[0008] S40: Conduct interface, function, performance and full-process tests on the navigation enhancement payload device, ground navigation enhancement terminal, navigation data center, navigation signal simulator and channel simulator to verify the correctness of the navigation enhancement system signal and information link design, signal generation and data processing.

[0009] In a specific embodiment, the S10 includes:

[0010] The onboard rubidium clock provides a reference frequency signal for the navigation enhancement payload device and the navigation monitoring receiver.

[0011] The navigation monitoring receiver receives the navigation signal simulator signal for positioning and timing.

[0012] The navigation enhancement payload device performs time synchronization with the time information through the 1PPS output by the satellite-borne navigation monitoring receiver.

[0013] In a specific embodiment, the S20 includes:

[0014] The navigation data center generates a low-orbit satellite simulation ephemeris,

[0015] The navigation signal simulator generates a low-orbit satellite simulation signal based on the ephemeris data and sends the signal to the navigation enhancement terminal.

[0016] The navigation enhancement terminal is tested for functions and performance indicators based on the low-orbit satellite simulation signal.

[0017] In a specific embodiment, when performing S30, the navigation signal simulator sends a GNSS signal simulating a low-orbit satellite trajectory to the onboard monitoring receiver, and sends a GNSS signal simulating a ground user trajectory to the navigation enhancement terminal and the channel simulator.

[0018] In a specific embodiment, the method further comprises:

[0019] S50: Connecting the navigation enhancement payload device to the payload interface matching device, and controlling the navigation enhancement payload device and transmitting and receiving data.

[0020] In a specific embodiment, the transmitting antenna of the navigation enhancement payload device and the receiving antenna of the navigation enhancement terminal are placed in a microwave dark box.

[0021] In a specific embodiment, the navigation enhancement payload device, the onboard navigation monitoring receiver, the navigation signal simulator and the onboard rubidium clock are placed in a microwave darkroom.

[0022] The beneficial effects of the present invention are as follows:

[0023] The present invention proposes a testing method for a navigation augmentation system. The method uses a navigation signal simulator to synchronously simulate satellite trajectories and ground user trajectories, thereby ensuring consistency with a real satellite on-orbit scene and signal and time uniformity between the satellite and the ground. The method uses simulated ground station observation data and observation data calculated in real time by a navigation monitoring receiver to simulate the system's operating conditions when the satellite is on-orbit in the most realistic way. Signals and information transmission from transmission to reception can be processed in a closed loop and in real time, thereby testing the functions and performance of equipment within the system to the greatest extent possible. The accuracy of the navigation augmentation system can be tested through closed-loop simulation. Navigation augmentation information is generated through data processing, broadcast through a payload device, and received by a ground terminal through high-precision positioning processing, thereby testing the service accuracy of the navigation augmentation system. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 A schematic flow chart showing a method for testing a navigation enhancement system according to an embodiment of the present invention is shown;

[0026] Figure 2 A block diagram of a satellite payload subsystem test according to an embodiment of the present invention is shown;

[0027] Figure 3 A navigation enhancement terminal test block diagram according to an embodiment of the present invention is shown;

[0028] Figure 4 A block diagram showing a time system connection relationship according to an embodiment of the present invention is shown;

[0029] Figure 5 Shows the testing of a navigation enhancement system according to one embodiment of the present invention;

[0030] Figure 6 A schematic diagram of a peripheral interface of a navigation enhancement payload device according to one embodiment of the present invention is shown;

[0031] Figure 7 The low-orbit satellite enhanced GNSS mode according to one embodiment of the present invention is shown;

[0032] Figure 8 The low-orbit satellite backup navigation and positioning mode according to one embodiment of the present invention is shown;

[0033] Figure 9The following illustrates a mode in which a satellite-borne receiver autonomously generates low-orbit satellite ephemeris according to an embodiment of the present invention. DETAILED DESCRIPTION

[0034] To make the technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0035] like Figure 1 As shown, an embodiment of the present invention provides a method for testing a navigation enhancement system, comprising:

[0036] S10: Conduct interface matching test and function and performance index test on navigation enhancement payload, onboard navigation monitoring receiver and onboard rubidium clock;

[0037] like Figure 2 As shown in Figure 1, this phase involves integration testing of the navigation augmentation payload, onboard navigation monitoring receiver, and miniaturized onboard rubidium clock. This phase also includes testing the interface compatibility between the various components / units of the onboard payload subsystem, which consists of the navigation augmentation payload, onboard navigation monitoring receiver, and miniaturized onboard rubidium clock, as well as testing the subsystem's functionality and performance indicators.

[0038] Specifically, the S10 includes: the satellite-borne rubidium clock provides a reference frequency signal for the navigation enhancement payload device and the navigation monitoring receiver,

[0039] The navigation monitoring receiver receives the navigation signal simulator signal for positioning and timing.

[0040] The navigation enhancement payload device performs time synchronization with the time information through the 1PPS output by the satellite-borne navigation monitoring receiver.

[0041] S20: Navigation enhancement terminal for testing;

[0042] like Figure 3 As shown, this stage is an independent simulation and test, mainly used for terminal testing, simulation analysis, demonstration verification, etc. Specifically, the S20 includes: the navigation data center is responsible for system data simulation, generating low-orbit satellite simulation ephemeris, almanac, error model data, etc.

[0043] The navigation signal simulator generates a low-orbit satellite simulation signal based on the ephemeris data and sends it to the navigation enhancement terminal. Before docking with the payload, it verifies the functions and performance indicators of the navigation enhancement terminal in advance, and can be used to verify the independent navigation and positioning capabilities of single and multiple low-orbit satellites.

[0044] The navigation enhancement terminal is tested for functions and performance indicators based on the low-orbit satellite simulation signal.

[0045] S30: Synchronizing the time of the navigation enhancement payload device, the onboard navigation monitoring receiver, the navigation enhancement terminal, the channel simulator and the navigation data center;

[0046] like Figure 4 As shown in the figure, the navigation augmentation system joint debugging test needs to ensure the time synchronization of the navigation augmentation payload, satellite-borne navigation monitoring receiver, navigation augmentation terminal (ground monitoring station), channel simulator, and navigation data center. Among them, the satellite-borne navigation monitoring receiver, navigation augmentation terminal (ground monitoring station), and channel simulator interface matching equipment can all receive simulated GNSS satellite navigation signals through line feeding or receive signals output by the multi-carrier navigation signal simulator through air feeding, thereby ensuring system time synchronization.

[0047] Because the onboard navigation monitoring receiver and ground equipment (navigation enhancement terminal, channel simulator) require different carrier trajectories, the present invention uses a navigation signal simulator to send GNSS signals simulating low-orbit satellite trajectories to the onboard monitoring receiver, and sends GNSS signals simulating ground user trajectories to the navigation enhancement terminal and channel simulator, which not only meets the simulation conditions of the equipment but also ensures system time synchronization;

[0048] Before the test, a fixed scenario can be simulated. The simulation start time, ephemeris, satellite trajectory, and ground station position are all fixed. The test is repeatable. Before each test, it is only necessary to adjust the navigation signal simulator time to a time earlier than the simulation start time.

[0049] S40: Conduct interface, function, performance and full-process tests on the navigation enhancement payload device, ground navigation enhancement terminal, navigation data center, navigation signal simulator and channel simulator to verify the correctness of the navigation enhancement system signal and information link design, signal generation and data processing.

[0050] This stage is carried out indoors, such as Figure 5 As shown, a system cascade adjustment test is carried out, and test equipment such as navigation enhancement payload, ground navigation enhancement terminal, navigation data center, navigation signal simulator and channel simulator are connected to the test system to test the system interface, equipment functions and performance, and the entire system process. The correctness of the navigation enhancement system signal and information link design is verified, the correctness of signal generation and data processing is verified, and the navigation enhancement system functions and performance indicators are tested.

[0051] In an optional embodiment, the transmitting antenna of the navigation enhancement payload device and the receiving antenna of the navigation enhancement terminal are placed in a microwave darkroom.

[0052] In another optional embodiment, all equipment is tested in a microwave darkroom, for example, the navigation enhancement payload, onboard navigation monitoring receiver, navigation signal simulator and onboard rubidium clock are placed in a microwave darkroom.

[0053] The navigation data center can use the host computer simulation method. The orbit determination, clock estimation and low-orbit satellite ephemeris data are simulated in advance, synchronized with the simulation time of the navigation signal simulator, and sent to the payload at a fixed period. The data center simulation equipment is manually synchronized with the simulator time, and the startup time delay is within 2s.

[0054] The GNSS navigation signal simulator adopts dual-user output. One channel simulates the GNSS navigation signal received by the ground terminal (and outputs it to the channel simulator at the same time), and the other channel simulates the GNSS navigation signal received by the satellite-borne navigation receiver.

[0055] The low-orbit satellite navigation signal output by the payload transmitter is sent to the channel simulator after passing through the attenuator, and the signal size is controlled by the adjustable attenuator at the output end.

[0056] Payload interface matching equipment is used to simulate the satellite platform, connect to the payload interface, and perform operations such as controlling the payload and sending and receiving data.

[0057] In a specific embodiment, the method further comprises:

[0058] S50: Connecting the navigation enhancement payload device to the payload interface matching device, and controlling the navigation enhancement payload device and transmitting and receiving data.

[0059] like Figure 6 As shown in the figure, during the joint test of the navigation augmentation system, only the navigation augmentation payload participates in the satellite. It is necessary to develop the navigation augmentation payload interface matching equipment, power supply system and necessary tooling, simulate the interface between the satellite platform and the navigation augmentation payload, and ensure the safety and normal operation of the navigation augmentation payload during the system joint debugging.

[0060] The test method provided in this implementation can be verified in the low-orbit satellite enhanced GNSS mode, the low-orbit satellite backup navigation positioning mode, and the low-orbit satellite ephemeris autonomously generated by the onboard receiver mode. The first category is as follows: Figure 7 In the low-orbit satellite augmented GNSS service mode shown, the onboard navigation monitoring receiver transmits the GNSS observation data to the ground gateway station via the satellite communication link. The navigation data center combines the data from the ground monitoring station, processes the precise orbit, clock error, pseudorange and carrier correction data, and injects the data to the low-orbit satellite navigation augmentation payload through the gateway station, generating a navigation augmentation signal and broadcasting it to the ground. After receiving the GNSS signal and the low-orbit satellite navigation signal, the navigation augmentation terminal performs high-precision precise single-point positioning. At the same time, the ground navigation monitoring receiver monitors the quality of the navigation signal broadcast from the low orbit.

[0061] The second category is Figure 8 In the low-orbit satellite backup navigation and positioning service mode shown in the figure, the low-orbit satellite and the ground support system use satellite-to-ground links and inter-satellite links to achieve time synchronization. The low-orbit satellite uses the inter-satellite link to determine its orbit. The ground support system collects low-orbit satellite navigation signal data through ground monitoring stations, generates low-orbit satellite predicted ephemeris, time deviation and other navigation information, and uplinks it to the low-orbit satellite. The satellite generates and broadcasts navigation signals, and the user receiver receives the low-orbit satellite navigation signals to provide users with PVT information.

[0062] The third category is Figure 9 The satellite-borne navigation monitoring receiver autonomously generates LEO satellite ephemeris data in this mode. In this mode, navigation augmentation data and LEO ephemeris data are not generated by a ground-based navigation data center. Instead, the satellite-borne navigation monitoring receiver autonomously generates LEO satellite ephemeris data through onboard real-time orbit determination and orbit extrapolation.

[0063] The present invention proposes a testing method for a navigation augmentation system. Through a navigation signal simulator, the satellite trajectory and the ground user trajectory are synchronously simulated, which not only ensures the consistency with the actual satellite on-orbit scene, but also ensures the signal and time uniformity between the satellite and the ground; through the simulated ground station observation data and the observation data calculated in real time by the navigation monitoring receiver, the system working conditions when the satellite is in orbit are most realistically simulated, and the signal and information transmission from transmission to reception can be closed-loop processed in real time, so that the equipment functions and performances in the system can be tested to the greatest extent; the accuracy of the navigation augmentation system can be tested by closed-loop simulation, and navigation augmentation information is generated through data processing, broadcast by the payload device, and received by the ground terminal for high-precision positioning processing, so that the service accuracy of the navigation augmentation system can be tested.

[0064] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. A method for testing a navigation enhancement system, characterized in that: include: S10: Conduct interface matching test and function and performance index test on navigation enhancement payload, onboard navigation monitoring receiver and onboard rubidium clock; S20: Navigation enhancement terminal for testing; S30: Synchronizing the time of the navigation enhancement payload device, the onboard navigation monitoring receiver, the navigation enhancement terminal, the channel simulator and the navigation data center; S40: Conducting interface, function, performance, and full-process testing on the navigation augmentation payload, ground navigation augmentation terminal, navigation data center, navigation signal simulator, and channel simulator to verify the correctness of the navigation augmentation system signal and information link design, signal generation, and data processing; The navigation signal simulator is a multi-carrier navigation signal simulator; The S10 includes: The onboard rubidium clock provides a reference frequency signal for the navigation enhancement payload device and the navigation monitoring receiver. The navigation monitoring receiver receives the navigation signal simulator signal for positioning and timing. The navigation enhancement payload device is synchronized with the time information via the 1PPS output by the onboard navigation monitoring receiver; The S20 includes: The navigation data center generates a low-orbit satellite simulation ephemeris, The navigation signal simulator generates a low-orbit satellite simulation signal based on the ephemeris data and sends the signal to the navigation enhancement terminal. Performing function and performance index testing on the navigation augmentation terminal according to the low-orbit satellite simulation signal; When performing S30, the navigation signal simulator sends a GNSS signal simulating a low-orbit satellite trajectory to the onboard navigation monitoring receiver, and sends a GNSS signal simulating a ground user trajectory to the navigation enhancement terminal and the channel simulator.

2. The method according to claim 1, characterized in that The method further comprises: S50: Connecting the navigation enhancement payload device to the payload interface matching device, and controlling the navigation enhancement payload device and transmitting and receiving data.

3. The method according to claim 1, characterized in that The transmitting antenna of the navigation enhancement payload device and the receiving antenna of the navigation enhancement terminal are placed in a microwave dark box.

4. The method according to claim 1, wherein The navigation enhancement payload device, the satellite-borne navigation monitoring receiver, the navigation signal simulator and the satellite-borne rubidium clock are placed in a microwave darkroom.

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