Satellite and ground microwave laser mixed signal transmission system

Abstract

The invention discloses a satellite and ground microwave laser mixed signal transmission system, and belongs to the field of spaceflight measurement and control. The satellite microwave laser mixed signal transmission system comprises a satellite laser antenna, a satellite laser transceiving link, a satellite laser tracking receiver, a satellite antenna pointing control unit, a satellite radio frequency responder and a satellite radio frequency antenna. The ground microwave laser mixed signal transmission system comprises a ground laser antenna, a ground laser transceiving link, a ground laser tracking receiver, a ground radio frequency antenna, a ground radio frequency receiving link, a ground radio frequency tracking receiver and a ground antenna pointing control unit. According to the invention, high-efficiency and high-precision target tracking can be taken into consideration, the requirement of simultaneous transmission of radio frequency and laser is met, engineering implementation is facilitated, and practical value is achieved.

Description

Technical Field

[0001] The present invention relates to the field of aerospace measurement and control, and in particular to a satellite and ground microwave laser mixed signal transmission system. Background Art

[0002] Future deep space exploration missions will require information exchange between spacecraft Earth orbits, celestial body orbits, and throughout the entire mission cycle, as well as large-capacity mission data transmission. While ensuring signal transmission reliability, data transmission rates must also be taken into account. Traditional radio frequency measurement and control communication systems have the advantages of high transmission reliability and being less susceptible to weather effects. However, due to the long transmission distances and high attenuation of signals in deep space exploration missions, they can only achieve medium and low-rate data transmission, making it difficult to meet the future needs of large-scale data interaction between the earth and the sky. Laser measurement and control communication can achieve ultra-high-speed data transmission and has strong anti-interference capabilities, but the laser beam is extremely narrow, making beam alignment between targets difficult and time-consuming, and signal transmission is easily affected by weather. Combining the advantages of the two measurement and control communication methods, realizing radio frequency / laser fusion intelligent transmission is one of the future research directions in the field of deep space exploration. This method can significantly improve the measurement and control communication capabilities of deep space exploration missions.

[0003] To achieve RF / laser fusion transmission, ground stations must first achieve stable, high-precision tracking of spacecraft during their motion. In conventional deep space exploration missions, ground station antennas use RF beacon signals transmitted by spacecraft to track targets. RF signal beams are relatively wide, making target tracking easier and the technology mature. However, their tracking accuracy is relatively low, failing to meet the requirements for laser beam alignment. Laser capture and tracking technology can theoretically achieve extremely high target tracking accuracy, but the laser beam is extremely narrow, making beam scanning to capture targets over a wide area extremely time-consuming and with a low success rate. Summary of the Invention

[0004] In light of this, the present invention provides a satellite and ground-based microwave laser hybrid signal transmission system. This system can be used for microwave laser dual-link parallel tracking for deep space tracking and control, ensuring both timeliness and accuracy while maintaining target tracking. This system offers low engineering implementation costs and high practical value.

[0005] The object of the present invention is achieved like this:

[0006] A satellite microwave laser mixed signal transmission system, comprising:

[0007] Satellite laser antenna: Receives uplink laser signals from the ground laser antenna and outputs them to the satellite laser transceiver link. In addition, it receives downlink laser signals from the satellite laser transceiver link and transmits them to the ground. Furthermore, it receives the satellite laser antenna pointing adjustment information output by the satellite antenna pointing control unit and adjusts the antenna pointing.

[0008] Satellite laser transceiver link: Receives the uplink laser signal output by the satellite laser antenna and forwards it to the satellite laser tracking receiver via optical fiber. In addition, it generates a downlink laser signal and, under the control of the control signal output by the satellite antenna pointing control unit, selects whether to output it to the satellite laser antenna or stop outputting it.

[0009] Satellite laser tracking receiver: Receives the uplink laser signal output by the satellite laser transceiver link, performs optical signal recognition, and then calculates the optical signal deviation and outputs it to the satellite antenna pointing control unit;

[0010] Satellite antenna pointing control unit: divided into two working stages:

[0011] The first stage is the laser capture stage: a control signal is output to the satellite laser transceiver link to control the laser transceiver link to stop outputting the downlink laser signal until the uplink laser signal is received. The laser transceiver link is then controlled to output the downlink laser signal, and then the second stage is entered.

[0012] The second stage is the laser tracking stage: based on the optical signal deviation output by the satellite laser tracking receiver, the satellite laser antenna pointing control signal is calculated and output to the satellite laser antenna, which controls the satellite laser antenna to adjust its pointing direction in real time to achieve optical signal tracking.

[0013] Satellite RF beacon: generates and outputs downlink RF signals;

[0014] Satellite RF antenna: receives the downlink RF signal output by the satellite RF beacon and transmits it to the ground.

[0015] A ground-based microwave laser mixed signal transmission system, comprising:

[0016] Ground laser antenna: The ground laser antenna receives the downlink laser signal transmitted by the satellite laser antenna and outputs it to the ground laser transceiver link. In addition, it receives the uplink laser signal output by the ground laser transceiver link and transmits it to the satellite. In addition, it receives the ground laser antenna pointing control signal output by the ground antenna pointing control unit to adjust the antenna pointing.

[0017] Ground laser transceiver link: Receives downlink laser signals from the ground laser antenna and forwards them to the ground laser tracking receiver via optical fiber. In addition, it generates uplink laser signals and outputs them to the ground laser antenna.

[0018] Ground laser tracking receiver: Receives the downlink laser signal output by the ground laser transceiver link, performs optical signal recognition, and then calculates the optical signal deviation and outputs it to the ground antenna pointing control unit;

[0019] Ground RF antenna: Receives downlink RF signals from the satellite RF antenna and outputs them to the ground RF receiving link. In addition, it receives the ground RF antenna pointing control signal from the ground antenna pointing control unit to adjust the antenna pointing direction.

[0020] Ground RF receiving link: Receives the RF beacon signal output by the ground RF antenna, completes signal amplification, filtering, and down-conversion, and generates an intermediate frequency beacon signal output to the ground RF tracking receiver;

[0021] Ground RF tracking receiver: Receives the intermediate frequency beacon signal output by the ground RF receiving link, completes angle error demodulation, generates angle error information and outputs it to the ground antenna pointing control unit;

[0022] Ground antenna pointing control unit: controls the pointing direction of the ground laser antenna and ground RF antenna.

[0023] Furthermore, the ground antenna pointing control unit is divided into four working stages:

[0024] The first stage, the RF tracking stage, receives the angular error information output by the ground RF tracking receiver, generates a ground RF antenna pointing control signal and outputs it to the ground RF antenna. This controls the ground RF antenna in real time to adjust its pointing direction, track the target, and limit the pointing error of the ground laser antenna to within the scanning range. This then transitions to the second stage.

[0025] The second stage is the laser capture stage: the control signal is output to the ground laser transceiver link to control the laser transceiver link to output the uplink laser signal. At the same time, the pointing control signal is output to the ground laser antenna to control the ground laser antenna to scan within the specified range until the downlink laser signal is received. The scanning stops and then enters the third stage.

[0026] The third stage is the laser tracking stage: based on the optical signal deviation output by the ground laser tracking receiver, a ground laser antenna pointing control signal is calculated and output to the ground laser antenna. The ground laser antenna is controlled in real time to adjust its pointing direction and track the target, which then transitions to the fourth stage.

[0027] The fourth phase, parallel tracking, involves simultaneous microwave and laser tracking. The RF antenna adjusts its direction based on the angular error information, and the laser antenna adjusts its direction synchronously with the RF antenna to track the downlink laser signal.

[0028] In the parallel tracking stage, a decoupled tracking method or a fusion tracking method is adopted; in the decoupled tracking method, the RF antenna and the laser antenna are tracked independently; in the fusion tracking method, the laser tracking information is used to correct the microwave tracking information.

[0029] Furthermore, the ground laser antenna is arranged on the main reflection surface of the ground radio frequency antenna. When the ground radio frequency antenna adjusts its direction, the ground laser antenna adjusts its direction simultaneously with the ground radio frequency antenna.

[0030] Compared with the background technology, the present invention has the following advantages:

[0031] (1) The present invention designs two signal transmission links, radio frequency and laser. The radio frequency signal has a wide beam, which is used to achieve rapid target capture and tracking; the laser signal has a narrow beam, which is responsible for achieving large-bandwidth data transmission, thereby achieving the complementary advantages of radio frequency and laser transmission;

[0032] (2) The radio frequency antenna and the laser antenna in the ground system of the present invention adopt a synchronous pointing design. When the radio frequency antenna adjusts its pointing direction to track the target, the laser antenna also adjusts its pointing direction synchronously, thereby achieving rapid and rough alignment of the laser beam.

[0033] (3) The radio frequency antenna and the laser antenna in the ground system of the present invention have autonomous tracking capabilities. When the two are tracking in parallel, they can operate in either a decoupled tracking mode or a fusion tracking mode, which is flexible and takes into account both timeliness and tracking accuracy.

[0034] (4) In terms of engineering implementation, the present invention only requires the addition of an antenna pointing control unit to the ground system on the basis of a conventional system for unified management of microwave tracking and laser tracking; and the addition of a radio frequency beacon machine to the satellite system for radio frequency beacon signal transmission. The system is simple to implement, low-cost, and has high engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a principle block diagram of an embodiment of the present invention.

[0036] Figure 2 It is a complete workflow diagram of an embodiment of the present invention. DETAILED DESCRIPTION

[0037] The present invention will be described in further detail below with reference to the accompanying drawings.

[0038] A satellite microwave laser mixed signal transmission system, such as Figure 1 The onboard system includes:

[0039] Satellite laser antenna 1: Receives the uplink laser signal transmitted by the ground laser antenna and outputs it to the satellite laser transceiver link. In addition, it receives the downlink laser signal output by the satellite laser transceiver link and transmits it to the ground. In addition, it receives the satellite laser antenna pointing adjustment information output by the satellite antenna pointing control unit and adjusts the antenna pointing.

[0040] Satellite laser transceiver link 2: Receives the uplink laser signal output by the satellite laser antenna and forwards it to the satellite laser tracking receiver via optical fiber. In addition, it generates a downlink laser signal and, under the control of the control signal output by the satellite antenna pointing control unit, selects whether to output it to the satellite laser antenna or stop outputting it.

[0041] Satellite laser tracking receiver 3: Receives the uplink laser signal output by the satellite laser transceiver link, performs optical signal recognition, and then calculates the optical signal deviation and outputs it to the satellite antenna pointing control unit;

[0042] Satellite antenna pointing control unit 4: divided into two working stages:

[0043] The first stage is the laser capture stage: a control signal is output to the satellite laser transceiver link to control the laser transceiver link to stop outputting the downlink laser signal until the uplink laser signal is received. The laser transceiver link is then controlled to output the downlink laser signal, and then the second stage is entered.

[0044] The second stage is the laser tracking stage: based on the optical signal deviation output by the satellite laser tracking receiver, the satellite laser antenna pointing control signal is calculated and output to the satellite laser antenna to control the satellite laser antenna to adjust its pointing direction in real time to achieve optical signal tracking;

[0045] Satellite RF beacon: generates and outputs downlink RF signals;

[0046] Satellite RF antenna 6: receives the downlink RF signal output by the satellite RF beacon and transmits it to the ground.

[0047] A ground-based microwave laser hybrid signal transmission system, such as Figure 1 The ground system is shown as follows, including:

[0048] Ground laser antenna 7: The ground laser antenna and ground RF antenna are synchronously controlled to ensure that the optical axis and electrical axis are aligned. The ground laser antenna receives the downlink laser signal transmitted by the satellite laser antenna and outputs it to the ground laser transceiver link. In addition, it receives the uplink laser signal output by the ground laser transceiver link and transmits it to the satellite. In addition, it receives the ground laser antenna pointing control signal output by the ground antenna pointing control unit to adjust the antenna pointing.

[0049] In this embodiment, the ground laser antenna is deployed on the main reflective surface of the ground radio frequency antenna. When the ground radio frequency antenna adjusts its direction, the ground laser antenna also adjusts its direction. At the same time, the ground laser antenna uses a fast reflector adjustment mechanism to quickly adjust the beam within a small range, which is used to achieve beam velocity scanning and tracking.

[0050] Ground laser transceiver link 8: Receives downlink laser signals from the ground laser antenna and forwards them to the ground laser tracking receiver via optical fiber. In addition, it generates uplink laser signals and outputs them to the ground laser antenna.

[0051] Ground laser tracking receiver 9: receives the downlink laser signal output by the ground laser transceiver link, performs optical signal recognition, and then calculates the optical signal deviation and outputs it to the ground antenna pointing control unit;

[0052] Ground RF antenna 10: Receives downlink RF signals from the satellite RF antenna and outputs them to the ground RF receiving link. Also, it receives the ground RF antenna pointing control signal from the ground antenna pointing control unit and adjusts the antenna pointing direction.

[0053] Ground RF receiving link 11: Receives the RF beacon signal output by the ground RF antenna, completes signal amplification, filtering, and down-conversion, and generates an intermediate frequency beacon signal output to the ground RF tracking receiver;

[0054] Ground RF tracking receiver 12: receives the intermediate frequency beacon signal output by the ground RF receiving link, completes angle error demodulation, generates angle error information and outputs it to the ground antenna pointing control unit;

[0055] Ground antenna pointing control unit 13: controls the pointing of the ground laser antenna and ground radio frequency antenna, and is divided into four working stages:

[0056] The first stage, the RF tracking stage, receives the angular error information output by the ground RF tracking receiver, generates a ground RF antenna pointing control signal and outputs it to the ground RF antenna to control the ground RF antenna in real time to adjust its pointing direction, track the target, and limit the pointing error of the ground laser antenna to the scannable range. This then transitions to the second stage.

[0057] The second stage is the laser capture stage, which outputs a control signal to the ground laser transceiver link to control the laser transceiver link to output an uplink laser signal. At the same time, it outputs a pointing control signal to the ground laser antenna to control the ground laser antenna to scan within a specified range until it receives a downlink laser signal. The scanning stops and then enters the third stage.

[0058] The third stage is the laser tracking stage. Based on the optical signal deviation output by the ground laser tracking receiver, a ground laser antenna pointing control signal is calculated and output to the ground laser antenna to adjust the pointing direction of the ground laser antenna in real time to track the target. This then transitions to the fourth stage.

[0059] In the fourth stage, the parallel tracking stage, microwave tracking and laser tracking are carried out simultaneously. The RF antenna adjusts its pointing direction according to the angular error information. While the laser antenna adjusts its pointing direction synchronously with the RF antenna, it has the ability to autonomously adjust its pointing direction in a small range to track the downlink laser signal. During parallel tracking, either decoupled tracking or fusion tracking can be selected. In the decoupled tracking mode, the RF antenna and laser antenna track independently. In the fusion tracking mode, the laser tracking information can be used to correct the microwave tracking information to improve the microwave tracking accuracy.

[0060] Onboard and ground systems work together, such as Figure 2 As shown in the figure, its working process is: it goes through ground RF coarse tracking, ground laser beam scanning, satellite laser capture, ground laser fine tracking, and ground fusion tracking processes in sequence. Specifically, the satellite RF beacon generates a downlink RF signal and transmits it to the ground through the satellite RF antenna. After the ground RF antenna receives the downlink RF signal, it sends it to the ground RF receiving link to complete signal amplification, filtering, and down-conversion to generate an intermediate frequency signal and output it to the ground RF tracking receiver. The ground RF tracking receiver completes the angular error demodulation and sends it to the ground antenna pointing control unit. The ground antenna pointing control unit generates a control signal based on the angular error information to control the ground RF antenna to point to the target, completing the ground RF coarse tracking and controlling the ground laser antenna pointing error within a small range. Subsequently, the ground antenna pointing control unit controls the ground laser transceiver link to generate an uplink laser signal and controls the ground laser antenna to scan within the specified range. The satellite After the laser antenna receives the uplink laser signal, the satellite laser tracking receiver performs optical signal identification. After identifying the uplink laser signal, the satellite antenna pointing control unit controls the laser transceiver link to output the downlink laser signal, and adjusts the satellite laser antenna pointing according to the optical signal deviation to complete the satellite laser capture; Subsequently, the ground laser antenna receives the downlink laser signal. According to the optical signal deviation output by the ground laser tracking receiver, the ground antenna pointing control unit calculates and generates a ground laser antenna pointing control signal, and outputs it to the ground laser antenna to control the ground laser antenna to adjust its pointing in real time and complete ground laser precision tracking; Finally, the ground antenna pointing control unit uses the optical signal deviation information to correct the angular error information, and generates a ground RF antenna pointing control signal based on the correction result and outputs it to the ground RF antenna to control the ground RF antenna to adjust its pointing in real time and carry out ground fusion tracking.

[0061] This invention combines rapid coarse RF tracking with precise laser tracking, enabling parallel tracking of RF and laser dual links. During parallel tracking, either decoupled tracking or fused tracking can be selected. In decoupled tracking, the RF antenna and laser antenna track independently. In fused tracking, laser tracking information can be used to correct microwave tracking information, improving microwave tracking accuracy while maintaining target tracking timeliness.

[0062] At the engineering implementation level, the present invention only requires adding an antenna pointing control unit to the conventional system, which is low-cost and easy to implement, and can meet the requirements for stable and high-precision tracking of spacecraft required for RF / laser fusion intelligent transmission in deep space tracking and control missions.

[0063] In summary, in response to the requirements for stable and high-precision tracking of spacecraft required for RF / laser fusion intelligent transmission in future deep space tracking and control missions, the present invention adopts a method of combining RF fast coarse tracking with laser precise tracking to achieve RF laser dual-link parallel tracking, which ensures tracking accuracy while taking into account the timeliness of target tracking and meets the needs of simultaneous RF and laser transmission.

Claims

1. A satellite microwave laser mixed signal transmission system, characterized in that: include: Satellite laser antenna: Receives uplink laser signals from the ground laser antenna and outputs them to the satellite laser transceiver link. In addition, it receives downlink laser signals from the satellite laser transceiver link and transmits them to the ground. Furthermore, it receives the satellite laser antenna pointing adjustment information output by the satellite antenna pointing control unit and adjusts the antenna pointing. Satellite laser transceiver link: Receives the uplink laser signal output by the satellite laser antenna and forwards it to the satellite laser tracking receiver via optical fiber. In addition, it generates a downlink laser signal and, under the control of the control signal output by the satellite antenna pointing control unit, selects whether to output it to the satellite laser antenna or stop outputting it. Satellite laser tracking receiver: Receives the uplink laser signal output by the satellite laser transceiver link, performs optical signal recognition, and then calculates the optical signal deviation and outputs it to the satellite antenna pointing control unit; Satellite antenna pointing control unit: divided into two working stages: The first stage is the laser capture stage: a control signal is output to the satellite laser transceiver link to control the laser transceiver link to stop outputting the downlink laser signal until the uplink laser signal is received. The laser transceiver link is then controlled to output the downlink laser signal, and then the second stage is entered. The second stage is the laser tracking stage: based on the optical signal deviation output by the satellite laser tracking receiver, the satellite laser antenna pointing control signal is calculated and output to the satellite laser antenna, which controls the satellite laser antenna to adjust its pointing direction in real time to achieve optical signal tracking. Satellite RF beacon: generates and outputs downlink RF signals; Satellite RF antenna: receives the downlink RF signal output by the satellite RF beacon and transmits it to the ground.

2. A ground-based microwave laser hybrid signal transmission system, characterized in that: include: Ground laser antenna: The ground laser antenna receives the downlink laser signal transmitted by the satellite laser antenna and outputs it to the ground laser transceiver link; In addition, it receives the uplink laser signal output by the ground laser transceiver link and transmits it to the satellite; and receives the ground laser antenna pointing control signal output by the ground antenna pointing control unit to adjust the antenna pointing; Ground laser transceiver link: Receives downlink laser signals from the ground laser antenna and forwards them to the ground laser tracking receiver via optical fiber. In addition, it generates uplink laser signals and outputs them to the ground laser antenna. Ground laser tracking receiver: Receives the downlink laser signal output by the ground laser transceiver link, performs optical signal recognition, and then calculates the optical signal deviation and outputs it to the ground antenna pointing control unit; Ground RF antenna: receives the downlink RF signal output by the satellite RF antenna and outputs it to the ground RF receiving link; In addition, it receives a ground RF antenna pointing control signal output by a ground antenna pointing control unit and adjusts the antenna pointing; Ground RF receiving link: Receives the RF beacon signal output by the ground RF antenna, completes signal amplification, filtering, and down-conversion, and generates an intermediate frequency beacon signal output to the ground RF tracking receiver; Ground RF tracking receiver: Receives the intermediate frequency beacon signal output by the ground RF receiving link, completes angle error demodulation, generates angle error information and outputs it to the ground antenna pointing control unit; Ground antenna pointing control unit: controls the pointing direction of the ground laser antenna and ground RF antenna.

3. The terrestrial microwave laser hybrid signal transmission system according to claim 2, characterized in that: The ground antenna pointing control unit is divided into four working stages: The first stage, the RF tracking stage, receives the angular error information output by the ground RF tracking receiver, generates a ground RF antenna pointing control signal and outputs it to the ground RF antenna. This controls the ground RF antenna in real time to adjust its pointing direction, track the target, and limit the pointing error of the ground laser antenna to within the scanning range. This then transitions to the second stage. The second stage is the laser capture stage: the control signal is output to the ground laser transceiver link to control the laser transceiver link to output the uplink laser signal. At the same time, the pointing control signal is output to the ground laser antenna to control the ground laser antenna to scan within the specified range until the downlink laser signal is received. The scanning stops and then enters the third stage. The third stage is the laser tracking stage: based on the optical signal deviation output by the ground laser tracking receiver, a ground laser antenna pointing control signal is calculated and output to the ground laser antenna. The ground laser antenna is controlled in real time to adjust its pointing direction and track the target, which then transitions to the fourth stage. The fourth phase, parallel tracking, involves simultaneous microwave and laser tracking. The RF antenna adjusts its direction based on the angular error information, and the laser antenna adjusts its direction synchronously with the RF antenna to track the downlink laser signal. In the parallel tracking stage, a decoupled tracking method or a fusion tracking method is adopted; In decoupled tracking mode, the RF antenna and laser antenna are tracked independently; In the fusion tracking mode, the laser tracking information is used to correct the microwave tracking information.

4. The terrestrial microwave laser hybrid signal transmission system according to claim 2, characterized in that: The ground laser antenna is arranged on the main reflection surface of the ground radio frequency antenna. When the ground radio frequency antenna adjusts its direction, the ground laser antenna adjusts its direction simultaneously with the ground radio frequency antenna.

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