A satellite-borne short message remote control and telemetry transmission system for low-orbit satellites

Abstract

A satellite-borne short message remote control and telemetry transmission system applied to low-orbit satellites relates to the field of satellite communication technology, and solves the problem that traditional low-orbit satellites are limited by the coverage of the ground measurement and control network and cannot perform measurement and control services outside the measurement and control range. The system includes: a data center, a Beidou ground terminal, a Beidou GEO satellite system, a low-orbit satellite, and a ground measurement and control station; the data center generates a remote control command for the satellite, which is sent by the Beidou ground terminal to the Beidou GEO satellite system, and the Beidou GEO satellite system forwards it to the low-orbit satellite through an S-band link; the low-orbit satellite sends out the satellite's telemetry data, which is sent to the Beidou GEO satellite system through an L-band link, and the Beidou GEO satellite system forwards it to the Beidou ground terminal, and finally received by the data center, thereby realizing the measurement and control service. The present invention greatly expands the measurement and control range at the cost of smaller system complexity, power consumption, size, weight, etc.

Description

Technical Field

[0001] The invention relates to the technical field of satellite communications, and is a satellite-borne short message remote control and telemetry transmission system applied to a low-orbit satellite. Background Art

[0002] In current low-orbit satellites, satellite-to-ground tracking and control services are mainly completed by onboard computers, tracking and control transponders, tracking and control antennas, and ground tracking and control stations. The tracking and control transponders can select S-band, X-band, etc. according to the information rate, such as Figure 1 The remote control command is sent by the ground tracking and control station, and finally received by the onboard computer through the tracking and control antenna and tracking and control transponder; the satellite telemetry information is sent by the onboard computer, and finally transmitted to the ground through the tracking and control transponder and tracking and control antenna, and finally received by the ground tracking and control station.

[0003] Figure 2 The maximum coverage of the ground measurement and control network based on the three ground stations of "Kashgar-Jiamusi-Sanya" is shown. According to simulation calculations, the maximum measurement and control time of the ground-orbiting satellite is about 7,000 seconds per day. It can be seen that the coverage is mainly concentrated in the Asia-Pacific region. If it exceeds this coverage, it will be impossible to carry out measurement and control services, inject instructions, receive telemetry data, etc. At the same time, according to the orbital characteristics of low-orbit satellites, the orbital period is usually 1 to 2 hours. If the satellite encounters abnormalities, emergency response and other emergencies outside the measurement and control range, it will take at least 1 to 2 hours for the satellite to re-enter the measurement and control range before it can be processed. This is a great disadvantage for satellite safety and the timeliness of mission execution.

[0004] The existing method to expand the measurement and control range is to use data relay satellites such as Tianlian and Tiantong for relay measurement and control. The working principle is as follows: Figure 3 As shown. Since relay satellites are generally located in geosynchronous orbits 36,000 kilometers above the ground, the coverage area is relatively large, but the number of relay satellites is small. Therefore, when designing the relay tracking and control transponder, the communication distance with the relay satellite is considered to be very large, usually requiring more than 44,000 kilometers. This requires that the transmission power of the relay tracking and control transponder and the gain of the relay tracking and control antenna are much larger than those of traditional tracking and control transponders. Therefore, the power consumption of the relay tracking and control transponder is usually very large, and it places high demands on the power supply capacity, heat dissipation capacity, and attitude pointing capability of the satellite platform. In addition, this method increases the complexity of the system and adds a lot of workload in terms of satellite-to-ground interface docking and ground data interface docking. Summary of the invention

[0005] In order to solve the problems existing in the prior art, the present invention provides a satellite-borne short message remote control and telemetry transmission system applied to low-orbit satellites, which focuses on solving the problem that traditional low-orbit satellites are limited by the coverage of the ground measurement and control network and cannot perform measurement and control services outside the measurement and control range.

[0006] The technical solution adopted by the present invention to solve the technical problem is as follows:

[0007] A satellite-borne short message remote control and telemetry transmission system applied to a low-orbit satellite, the system comprising: a data center, a Beidou ground terminal, a Beidou GEO satellite system, a low-orbit satellite and a ground measurement and control station; the data center generates a ground remote control instruction of the satellite, which is sent by the Beidou ground terminal to the Beidou GEO satellite system, and the Beidou GEO satellite system forwards it to the low-orbit satellite through an S-band link; the low-orbit satellite sends out the satellite's on-board telemetry data, which is sent to the Beidou GEO satellite system through an L-band link, and the Beidou GEO satellite system forwards it to the Beidou ground terminal, and finally received by the data center, thereby realizing measurement and control services.

[0008] Preferably, the low-orbit satellite includes: an onboard computer, an onboard short message terminal and a short message antenna; the Beidou GEO satellite system forwards the ground remote control instructions to the short message terminal through the S-band link via the short message antenna, and the onboard computer receives the information sent by the short message terminal through the CAN bus; the onboard telemetry information is sent by the onboard computer through the CAN bus, and after being received by the onboard short message terminal, it is sent to the Beidou GEO satellite system through the L-band link by the short message antenna.

[0009] Preferably, the low-orbit satellite includes: a tracking and control transponder and a tracking and control antenna; the data center generates remote control instructions for the satellite, which are sent by the ground tracking and control station and sent to the tracking and control transponder via the tracking and control antenna, and the onboard computer receives the information sent by the tracking and control transponder via the CAN bus; the satellite telemetry information is sent by the onboard computer, transmitted to the ground via the CAN bus through the tracking and control transponder, and the tracking and control antenna, and finally received by the ground tracking and control station.

[0010] Preferably, the Beidou GEO satellite system includes N satellites, where N≥1.

[0011] The beneficial effects of the present invention are:

[0012] 1. Incorporate the satellite-borne Beidou short message terminal into the measurement and control subsystem, and use the short message communication function of the Beidou system to transmit the satellite's remote control commands and telemetry information, expand the measurement and control range of low-orbit satellites, ensure the timely upload of important commands and the timely download of important telemetry information, and ensure the safety of the satellite and the timeliness of mission execution.

[0013] 2. When the satellite is outside the coverage of the ground measurement and control network, the onboard short message terminal can temporarily replace the measurement and control transponder, power off the entire measurement and control transponder or only turn off the transmission function of the measurement and control transponder, reducing the power consumption of the measurement and control subsystem. When the satellite enters the coverage of the ground measurement and control network, the onboard short message terminal can be used to turn on the measurement and control transponder and then carry out conventional measurement and control services.

[0014] 3. The present invention greatly expands the scope of measurement and control at the cost of lower system complexity, power consumption, size, weight, etc. The present invention has achieved a reasonable solution, is easy to implement, and can meet the application needs of the growing measurement and control business of low-orbit satellites. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Working diagram of traditional satellite tracking and control subsystem

[0016] Figure 2 The largest coverage of the domestic ground measurement and control network

[0017] Figure 3 Relay measurement and control working diagram

[0018] Figure 4 Working diagram of the modified measurement and control subsystem

[0019] Figure 5 L-beam coverage diagram

[0020] Figure 6 S-beam coverage diagram

[0021] Figure 7 Effective coverage of BeiDou-2 system short message service

[0022] Figure 8 Schematic diagram of short message communication involving multiple GEO satellites

[0023] Fig. 9 A flow chart of a remote control and telemetry transmission system using a satellite-borne short message terminal. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0025] like Figure 4As shown, a satellite-borne short message remote control and telemetry transmission system applied to a low-orbit satellite, the system comprising: a data center, a Beidou ground terminal, a Beidou GEO satellite system, a low-orbit satellite and a ground measurement and control station; the data center generates a satellite remote control instruction, which is sent by the Beidou ground terminal to the Beidou GEO satellite system, and the Beidou GEO satellite system forwards it to the low-orbit satellite via an S-band link; the low-orbit satellite sends out the satellite telemetry data, which is sent to the Beidou GEO satellite system via an L-band link, and the Beidou GEO satellite system forwards it to the Beidou ground terminal, which is finally received by the data center, thereby realizing measurement and control services. Among them, the low-orbit satellite includes: an onboard computer, an onboard short message terminal and a short message antenna; the Beidou GEO satellite system forwards the ground remote control instructions to the short message terminal through the S-band link via the short message antenna, and the onboard computer receives the information sent by the short message terminal through the CAN bus; the on-board telemetry information is sent by the onboard computer through the CAN bus, and after being received by the onboard short message terminal, it is sent to the Beidou GEO satellite system through the L-band link by the short message antenna.

[0026] Short message communication is provided by the BeiDou-2 5 GEO satellite system. The service area of ​​the RDSS payload of the BeiDou-2 regional system 5 GEO satellite system is as follows: Figure 5 to Figure 7 shown.

[0027] The low-orbit satellite includes: a telemetry transponder and a telemetry antenna; the data center generates satellite remote control instructions, which are sent by the ground telemetry station and sent to the telemetry transponder via the telemetry antenna, and the satellite computer receives the information sent by the telemetry transponder via the CAN bus; satellite telemetry information is sent by the satellite computer, transmitted to the ground via the CAN bus through the telemetry transponder and the telemetry antenna, and finally received by the ground telemetry station. The satellite computer, the satellite short message terminal and the telemetry transponder communicate via the CAN bus.

[0028] In this embodiment, the transmission path of the short message can be specifically divided into two cases:

[0029] (1) Transmission path such as Figure 4 As shown, the satellite-borne short message terminal and the Beidou ground terminal communicate with the same Beidou GEO satellite, and the transmission path is "Beidou ground terminal—Beidou GEO satellite—satellite-borne short message terminal".

[0030] (2) Transmission path such as Figure 8 As shown, the short message data packet needs to be forwarded through multiple Beidou GEO satellites, and the transmission path is "Beidou ground terminal—Beidou GEO satellite 1—…—Beidou GEO satellite N—…—Beidou GEO satellite 2—onboard short message terminal".

[0031] like Fig. 9As shown, a process of a remote control and telemetry transmission system for a satellite-borne short message terminal applied to a low-orbit satellite includes the following steps:

[0032] A: Satellite-borne short message terminal performs measurement and control services;

[0033] When a low-orbit satellite is outside the coverage of the ground measurement and control network, its measurement and control transponder is in the off state, and the measurement and control services are carried out through the short message terminal to realize the functions of remote control uplink and telemetry downlink.

[0034] B: The satellite enters the tracking and control area;

[0035] The ground receives the telemetry data transmitted by the short message, and determines whether the low-orbit satellite has entered the measurement and control area based on the position information of the navigation receiver in the telemetry of the low-orbit satellite. If it is determined that the satellite has entered the measurement and control area, execute step C.

[0036] C: The Beidou ground terminal sends a remote control command to turn on the measurement and control transponder;

[0037] If the ground needs the low-orbit satellite to perform routine tracking and control services, it will send remote control commands (turn on the tracking and control transponder command) to the low-orbit satellite through the Beidou ground terminal when the low-orbit satellite enters the tracking and control area. If there is no need to perform routine tracking and control services, the ground does not need to send commands.

[0038] D: Low-orbit satellites cooperate with ground stations to carry out routine measurement and control services;

[0039] The ground tracking station tracks the low-orbit satellite and completes the functions of uploading remote control commands, receiving telemetry information, and performing ranging and speed measurement through the tracking and control transponder. At the same time, the short message terminal also transmits satellite telemetry through the forwarding of the Beidou GEO satellite system. The two are carried out simultaneously without interfering with each other.

[0040] E: Low-orbit satellite leaves the tracking and control range;

[0041] The ground tracking and control station completed the tracking mission and the low-orbit satellite was out of the tracking and control range.

[0042] F: Beidou ground terminal sends remote control command to turn off the measurement and control transponder;

[0043] The Beidou ground terminal sends remote control commands (commands to shut down the tracking and control transponder) to low-orbit satellites to reduce the power consumption of the entire satellite.

[0044] G: The satellite-borne short message terminal performs measurement and control services.

[0045] When a low-orbit satellite is outside the coverage of the ground measurement and control network, the satellite measurement and control transponder is in the off state, and the measurement and control services are carried out through the short message terminal to realize the functions of remote control uplink and telemetry downlink.

Claims

1. A satellite-borne short message remote control and telemetry transmission system applied to low-orbit satellites, characterized in that: The system comprises: a data center, a Beidou ground terminal, a Beidou GEO satellite system, a low-orbit satellite and a ground measurement and control station; the data center generates ground remote control instructions for satellites, which are sent by the Beidou ground terminal to the Beidou GEO satellite system, and the Beidou GEO satellite system forwards them to the low-orbit satellite via an S-band link; the low-orbit satellite sends satellite on-board telemetry data, which are sent to the Beidou GEO satellite system via an L-band link, and the Beidou GEO satellite system forwards them to the Beidou ground terminal, which are finally received by the data center, thereby realizing measurement and control services; The low-orbit satellite comprises: an onboard computer, an onboard short message terminal and a short message antenna; the Beidou GEO satellite system forwards the ground remote control command to the short message terminal via the S-band link via the short message antenna, and the onboard computer receives the information sent by the short message terminal via the CAN bus; the onboard telemetry information is sent by the onboard computer via the CAN bus, and after being received by the onboard short message terminal, it is sent to the Beidou GEO satellite system via the L-band link by the short message antenna; The low-orbit satellite comprises: a tracking and control transponder and a tracking and control antenna; the data center generates a remote control command of the satellite, which is sent by the ground tracking and control station and sent to the tracking and control transponder via the tracking and control antenna, and the onboard computer receives the information sent by the tracking and control transponder via the CAN bus; the satellite telemetry information is sent by the onboard computer, transmitted to the ground via the tracking and control transponder via the CAN bus, and the tracking and control antenna, and finally received by the ground tracking and control station; The process of the onboard short message remote control and telemetry transmission system applied to low-orbit satellites includes the following steps: A: Satellite-borne short message terminal performs measurement and control services; When a low-orbit satellite is outside the coverage of the ground measurement and control network, the measurement and control transponder is turned off, and the remote control uplink and telemetry downlink functions are realized through the short message terminal to carry out measurement and control services; B: The satellite enters the tracking and control area; The ground receives the telemetry data transmitted by the short message, and determines whether the low-orbit satellite has entered the measurement and control area according to the position information of the navigation receiver in the telemetry of the low-orbit satellite. If it is determined that the satellite has entered the measurement and control area, step C is executed; C: The Beidou ground terminal sends a command to turn on the tracking and control transponder to the low-orbit satellite to turn on the tracking and control transponder; D: Low-orbit satellites cooperate with ground tracking and control stations to carry out routine tracking and control services; The ground tracking station tracks the low-orbit satellite and completes the uploading of remote control commands, receiving telemetry information, and performing distance and speed measurement functions through the tracking and control transponder. At the same time, the short message terminal also forwards the satellite telemetry through the Beidou GEO satellite system, and the two are carried out simultaneously without interfering with each other. E: The low-orbit satellite leaves the tracking and control range, and the ground tracking and control station completes the tracking mission; F: The Beidou ground terminal sends a command to shut down the tracking and control transponder to the low-orbit satellite, shuts down the tracking and control transponder, and the onboard short message terminal performs tracking and control services.

2. The onboard short message remote control and telemetry transmission system for low-orbit satellites according to claim 1, characterized in that: The BeiDou GEO satellite system includes N satellites, where N≥1.

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