Dual-antenna satellite navigation terminal system and its on-board autonomous switching method and system

Abstract

The present invention provides a dual-antenna satellite navigation terminal system and its on-orbit autonomous switching method and system, including a satellite navigation receiver, a navigation preamplifier, a microwave switch, a ground-facing navigation antenna, and a sky-facing navigation antenna. The microwave switch performs channel switching between the ground-facing navigation antenna and the sky-facing navigation antenna. The present invention can be applied to a large elliptical frozen orbit satellite, and can realize dual-antenna autonomous switching navigation and positioning in the perigee arc segment and the apogee arc segment, ensuring the correctness and integrity of the navigation and positioning and orbit determination results of the large elliptical frozen orbit satellite during the entire on-orbit flight period.

Description

Technical Field

[0001] The present invention relates to the field of satellite navigation. Specifically, it relates to a dual-antenna satellite navigation terminal system applicable to a large elliptical frozen orbit, and in particular to a dual-antenna satellite navigation terminal system, an on-board autonomous switching method and system thereof. Background Art

[0002] A large elliptical frozen orbit is a special staying orbit. This orbit has been in use for a long time, starting from the 1960s. It has been widely used in fields such as communication, remote sensing, and environmental exploration. It has the characteristic of "quasi-stationary" relative to the mid-high latitude regions. It can not only improve the spatial relative position similar to that of a geostationary orbit but also improve the space-ground relative relationship with targets in the mid-high latitude regions, and is widely used by Russia and the United States. For a large elliptical frozen orbit with a period of about 12 hours and a critical inclination of 63.4°, the orbital altitude is about 1500 km to 38850 km. The orbital altitudes of BDS / GPS / GLONASS navigation satellites are about 20000 km. Currently, for low-orbit satellite navigation antennas, they are generally installed on the satellite's sky-facing surface to receive the zenith direct signals of BDS / GPS / GLONASS navigation satellites for navigation positioning and orbit determination; for geostationary orbit satellite navigation antennas, they are generally installed on the satellite's ground-facing surface to receive the BDS / GPS / GLONASS navigation signals from the opposite side of the earth (i.e., "leaked navigation satellite signals") for navigation positioning and orbit determination. Since satellites operating in a large elliptical frozen orbit need to continuously experience the changes of high, medium, and low orbits every day, it is no longer possible to rely on a single navigation antenna facing the ground or the sky to achieve the navigation positioning and orbit determination functions of large elliptical frozen orbit satellites.

[0003] In the Chinese patent document with the publication number CN105607077A, a spaceborne dual-mode four-frequency GNSS navigation receiver design is disclosed, which uses a single navigation antenna to input mixed signals and can provide precise orbit determination services for the space operation of low-orbit spacecraft. However, the single-antenna spaceborne GNSS navigation receiver design proposed in this patent document is not applicable to spacecraft in large elliptical orbits.

[0004] In the Chinese patent document with the publication number CN103675861A, a satellite autonomous orbit determination method based on spaceborne GNSS multi-antennas is disclosed. The measured pseudorange observations of multiple GNSS antennas are used to perform real-time filtering and correction on the orbit prediction values obtained by a high-precision mechanical model to obtain high-precision satellite orbit information. However, this patent document only proposes an autonomous orbit determination algorithm, which can be applied to high-precision orbit determination for space missions such as space stations and high-resolution earth observation satellites, and is not applicable to spacecraft in large elliptical orbits. Summary of the Invention

[0005] Aiming at the defects in the prior art, the purpose of the present invention is to provide a dual-antenna satellite navigation terminal system, an on-board autonomous switching method and system thereof.

[0006] A dual-antenna satellite navigation terminal system provided by the present invention includes: a satellite navigation receiver, a navigation preamplifier, a microwave switch, a ground-oriented navigation antenna, and a sky-oriented navigation antenna. The microwave switch switches channels between the ground-oriented navigation antenna and the sky-oriented navigation antenna. The satellite navigation receiver broadcasts satellite flight data. The navigation preamplifier receives navigation signals from the ground-oriented navigation antenna and the sky-oriented navigation antenna, amplifies the navigation signals, and then transmits them to the satellite navigation receiver.

[0007] Preferably, the satellite navigation receiver supports multiple mode compatibility combinations or multiple different frequency point compatibility combinations.

[0008] Preferably, the multiple mode compatibility combinations include any one or any combination of BDS, GPS, and GLONASS.

[0009] Preferably, the multiple different frequency point compatibility combinations include the L1 and L2 bands of GPS, the B1, B2, and B3 bands of BDS, and the G1 and G2 bands of GLONASS.

[0010] An on-board autonomous switching method for a dual-antenna satellite navigation terminal system provided by the present invention includes the following steps:

[0011] Step S1: The satellite navigation receiver continuously receives navigation satellite signals to complete real-time calculation, performs real-time orbit determination or orbit extrapolation for the entire period of the satellite's in-orbit flight. The satellite navigation receiver periodically broadcasts the orbit determination data through a serial data bus. The orbit determination broadcast data includes real-time / extrapolation flags, whole-second time, and the corresponding six orbital elements.

[0012] Step S2: The integrated electronic computer periodically receives the orbit determination broadcast data of the satellite navigation receiver, monitors the real-time / extrapolation flags in the orbit determination broadcast data. If the real-time / extrapolation flag switches from real-time orbit determination to orbit extrapolation, a variable is set for timing accumulation. If the real-time / extrapolation flag switches from orbit extrapolation to real-time orbit determination, the count value is cleared. The integrated electronic computer calculates the orbital altitude through the semi-major axis and eccentricity of the orbit in the orbit determination broadcast data.

[0013] Step S3: When the timing after the real-time / extrapolation flag switches from real-time orbit determination to orbit extrapolation exceeds a preset time, and the calculated orbital altitude exceeds a preset altitude, an on-board autonomous switch is made between the ground-oriented navigation antenna and the sky-oriented navigation antenna. When the timing after the real-time / extrapolation flag switches from real-time orbit determination to orbit extrapolation does not exceed the preset time, or the orbital altitude does not exceed the preset altitude, return to Step S2.

[0014] Preferably, the serial data bus includes a data communication bus with the 1553B or CAN standard protocol, and the serial data bus is configured with single, dual or multi-redundant buses.

[0015] Preferably, the integrated electronic computer is a computer with data management functions.

[0016] A on-board autonomous switching system of a dual-antenna satellite navigation terminal system provided by the present invention includes the following modules:

[0017] Module M1: The satellite navigation receiver continuously receives navigation satellite signals to complete real-time calculation, performs real-time orbit determination or orbit extrapolation for the entire period of the satellite's on-orbit flight. The satellite navigation receiver periodically broadcasts the orbit determination data through the serial data bus. The orbit determination broadcast data includes real-time / extrapolation flags, whole-second time, and the corresponding six orbital elements.

[0018] Module M2: The integrated electronic computer periodically receives the orbit determination broadcast data of the satellite navigation receiver, monitors the real-time / extrapolation flags in the orbit determination broadcast data. If the real-time / extrapolation flag switches from real-time orbit determination to orbit extrapolation, a variable is set for timing and accumulation. If the real-time / extrapolation flag switches from orbit extrapolation to real-time orbit determination, the count value is cleared. The integrated electronic computer calculates the orbit altitude based on the semi-major axis and eccentricity of the orbit in the orbit determination broadcast data.

[0019] Module M3: When the timing after the real-time / extrapolation flag switches from real-time orbit determination to orbit extrapolation exceeds the preset time, and after calculating that the orbit altitude exceeds the preset altitude, an on-board autonomous switch between the ground navigation antenna and the skyward navigation antenna will be performed. When the timing after the real-time / extrapolation flag switches from real-time orbit determination to orbit extrapolation does not exceed the preset time, or the orbit altitude does not exceed the preset altitude, Module M2 is executed.

[0020] Preferably, the serial data bus includes a data communication bus with the 1553B or CAN standard protocol, and the serial data bus is configured with single, dual or multi-redundant buses.

[0021] Preferably, the integrated electronic computer is a computer with data management functions.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The present invention can be applied to satellites in highly elliptical frozen orbits, and can achieve dual-antenna autonomous switching navigation and positioning in the perigee arc segment and the apogee arc segment.

[0024] 2. The present invention adopts the technical scheme of dual-antenna / single preamplifier, and adopts the method of on-board autonomous switching microwave switch, relying on on-board autonomous switching without ground intervention.

[0025] 3. The system solution of the present invention is simple and reliable, which can ensure the correctness and integrity of the navigation and positioning and orbit determination results of the large elliptical frozen orbit satellite during the entire on-orbit flight period. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] By reading the following detailed description of the non-limiting embodiments with reference to the accompanying drawings, other features, objects, and advantages of the present invention will become more apparent:

[0027] Figure 1 It is a schematic structural diagram of the dual-antenna satellite navigation terminal system according to an embodiment of the present invention;

[0028] Figure 2 It is a flowchart of the on-board autonomous switching method of the dual-antenna satellite navigation terminal system according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several changes and improvements can still be made. These all belong to the protection scope of the present invention.

[0030] The present invention introduces a dual-antenna satellite navigation terminal system. Referring to Figure 1 as shown, the system includes a satellite navigation receiver, a navigation preamplifier, a microwave switch, a ground-facing navigation antenna, and a sky-facing navigation antenna. The microwave switch switches the channels of the ground-facing navigation antenna and the sky-facing navigation antenna. The satellite navigation receiver broadcasts satellite flight data. The navigation preamplifier receives the navigation signals from the ground-facing navigation antenna and the sky-facing navigation antenna, and amplifies the navigation signals and then transmits them to the satellite navigation receiver.

[0031] The satellite navigation receiver supports multiple mode compatibility combinations or multiple different frequency point compatibility combinations. The multiple mode compatibility combinations include any one or any combination of BDS, GPS, and GLONASS. The multiple different frequency point compatibility combinations include the L1 and L2 bands of GPS, the B1, B2, and B3 bands of BDS, and the G1 and G2 bands of GLONASS.

[0032] The integrated electronic computer periodically receives the orbit determination data broadcast by the satellite navigation receiver through the serial data bus, makes an autonomous judgment, and performs on-board autonomous switching of the ground-facing navigation antenna and the sky-facing navigation antenna after meeting certain conditions. Among them, the integrated electronic computer can be other computers with data management functions, and the serial data bus can be a data communication bus that executes any standard protocol such as 1553B or CAN. The bus form can be configured as a single, dual, or multi-redundant bus.

[0033] The present invention also introduces an on-board autonomous switching method for a dual-antenna satellite navigation terminal system, as Figure 2 shown. This method includes the following steps:

[0034] Step S1: The satellite navigation receiver continuously receives BDS / GPS / GLONASS navigation satellite signals to complete real-time calculation, performs real-time orbit determination or orbit extrapolation for the entire period of the satellite's on-orbit flight, and periodically broadcasts the orbit determination data through a serial data bus. The orbit determination broadcast data includes information such as real-time / extrapolation flags, whole-second time, and the corresponding six orbital elements, etc.

[0035] Step S2: The integrated electronic computer periodically receives the orbit determination broadcast data of the satellite navigation receiver, monitors the real-time / extrapolation flag in the orbit determination broadcast data. If the real-time / extrapolation flag switches from real-time orbit determination to orbit extrapolation, a variable is set for timing accumulation. If the real-time / extrapolation flag switches from orbit extrapolation to real-time orbit determination, the count value is cleared; the integrated electronic computer calculates the orbital altitude H through the semi-major axis a of the orbit, orbital eccentricity e, and true anomaly f, etc. in the orbit determination broadcast data.

[0036] The calculation formula for the orbital altitude H is as follows:

[0037]

[0038] Step S3: If the timing exceeds a certain time (the in-orbit injection number can be modified) after the real-time / extrapolation flag switches from real-time orbit determination to orbit extrapolation, and the calculated orbital altitude exceeds a certain altitude (the in-orbit injection number can be modified), then an on-board autonomous switching between the ground navigation antenna and the skyward navigation antenna will be performed. Otherwise, it will enter Step S2.

[0039] Those skilled in the art know that in addition to implementing the system and its various devices, modules, and units provided by the present invention in the form of pure computer-readable program code, the method steps can be logically programmed to enable the system and its various devices, modules, and units provided by the present invention to be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers, etc. to achieve the same functions. Therefore, the system and its various devices, modules, and units provided by the present invention can be considered as a hardware component, and the devices, modules, and units included therein for implementing various functions can also be regarded as the structure within the hardware component; the devices, modules, and units for implementing various functions can also be regarded as either software modules for implementing the method or the structure within the hardware component.

[0040] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0041] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Without conflict, the embodiments of the present application and the features in the embodiments can be arbitrarily combined with each other.

Claims

1. An on-board autonomous switching method for a dual-antenna satellite navigation terminal system, characterized in that It includes the following steps: Step S1: The satellite navigation receiver continuously receives navigation satellite signals to complete real-time calculation, performs real-time orbit determination or orbit extrapolation for the entire period of the satellite's in-orbit flight. The satellite navigation receiver periodically broadcasts the orbit determination data through a serial data bus. The orbit determination broadcast data includes a real-time / extrapolation flag, the whole second time, and the corresponding six orbital elements; Step S2: The integrated electronic computer periodically receives the orbit determination broadcast data from the satellite navigation receiver, monitors the real-time / extrapolation flag in the orbit determination broadcast data. If the real-time / extrapolation flag switches from real-time orbit determination to orbit extrapolation, a variable is set for timing accumulation. If the real-time / extrapolation flag switches from orbit extrapolation to real-time orbit determination, the count value is cleared; The integrated electronic computer calculates the orbit altitude through the semi-major axis and eccentricity of the orbit in the orbit determination broadcast data; Step S3: When the timing after the real-time / extrapolation flag switches from real-time orbit determination to orbit extrapolation exceeds the preset time, and after calculating that the orbit altitude exceeds the preset altitude, an on-board autonomous switch will be made between the ground navigation antenna and the skyward navigation antenna; When the timing after the real-time / extrapolation flag switches from real-time orbit determination to orbit extrapolation does not exceed the preset time, or the orbit altitude does not exceed the preset altitude, return to Step S2.

2. The on-board autonomous switching method of the dual-antenna satellite navigation terminal system according to claim 1, characterized in that: The serial data bus includes a data communication bus with 1553B or CAN standard protocol, and the serial data bus is configured with single, dual, or multi-redundant buses.

3. The on-board autonomous switching method of the dual-antenna satellite navigation terminal system according to claim 1, wherein: The integrated electronic computer is a computer with data management functions.

4. An on-board autonomous switching system for a dual-antenna satellite navigation terminal system, characterized in that, It includes the following modules: Module M1: The satellite navigation receiver continuously receives navigation satellite signals to complete real-time calculation, performs real-time orbit determination or orbit extrapolation for the entire period of the satellite's in-orbit flight. The satellite navigation receiver periodically broadcasts the orbit determination data through a serial data bus. The orbit determination broadcast data includes a real-time / extrapolation flag, the whole second time, and the corresponding six orbital elements; Module M2: The integrated electronic computer periodically receives the orbit determination broadcast data from the satellite navigation receiver, monitors the real-time / extrapolation flag in the orbit determination broadcast data. If the real-time / extrapolation flag switches from real-time orbit determination to orbit extrapolation, a variable is set for timing accumulation. If the real-time / extrapolation flag switches from orbit extrapolation to real-time orbit determination, the count value is cleared; The integrated electronic computer calculates the orbit altitude through the semi-major axis and eccentricity of the orbit in the orbit determination broadcast data; Module M3: When the timing after the real-time / extrapolation flag switches from real-time orbit determination to orbit extrapolation exceeds the preset time, and after calculating that the orbit altitude exceeds the preset altitude, an on-board autonomous switch will be made between the ground navigation antenna and the skyward navigation antenna; When the timing after the real-time / extrapolation flag switches from real-time orbit determination to orbit extrapolation does not exceed the preset time, or the orbit altitude does not exceed the preset altitude, execute Module M2.

5. The on-board autonomous switching system of the dual-antenna satellite navigation terminal system according to claim 4, characterized in that: The serial data bus includes a data communication bus with 1553B or CAN standard protocol, and the serial data bus is configured with single, dual, or multi-redundant buses.

6. The on-board autonomous switching system of the dual-antenna satellite navigation terminal system according to claim 4, characterized in that: The integrated electronic computer is a computer with data management functions.

7. A dual-antenna satellite navigation terminal system, which adopts the on-board autonomous switching method of the dual-antenna satellite navigation terminal system described in any one of claims 1-3, is characterized in that, It includes: A satellite navigation receiver, a navigation preamplifier, a microwave switch, a ground-facing navigation antenna, and a sky-facing navigation antenna. The microwave switch switches channels between the ground-facing navigation antenna and the sky-facing navigation antenna. The satellite navigation receiver broadcasts satellite flight data. The navigation preamplifier receives navigation signals from the ground-facing navigation antenna and the sky-facing navigation antenna, amplifies the navigation signals, and transmits them to the satellite navigation receiver.

8. The dual-antenna satellite navigation terminal system according to claim 7, characterized in that: The satellite navigation receiver supports multiple mode compatibility combinations or multiple different frequency point compatibility combinations.

9. The dual-antenna satellite navigation terminal system according to claim 8, characterized in that: The multiple mode compatibility combinations include any one or any combination of BDS, GPS, and GLONASS.

10. The dual-antenna satellite navigation terminal system according to claim 9, wherein: The multiple different frequency point compatibility combinations include the L1 and L2 bands of GPS, the B1, B2, and B3 bands of BDS, and the G1 and G2 bands of GLONASS.

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