Simulation verification test system and method for inter-satellite link of remote sensing satellites in stationary orbit

Abstract

The invention discloses a simulation verification test system for an inter-satellite link of a remote sensing satellite in a stationary orbit. The simulation verification test system comprises an other-satellite terminal simulator, a signal generating and sending module, an inter-satellite channel simulator and a signal receiving and processing module. The astronomical terminal simulator simulates and generates astronomical data; the signal generating and sending module is used for generating the other satellite data into a radio frequency other satellite signal; the inter-satellite channel simulator simulates the time-frequency characteristic of the radio frequency astronomical signal sent to a satellite, and generates the radio frequency astronomical signal with the time-frequency characteristic; the satellite receives and processes an uplink radio frequency other-satellite signal, and outputs the signal to the ground through an inter-satellite link downlink channel; and the ground signal receiving and processing module reanalyzes the radio frequency signal into a baseband signal, and the other-satellite terminal simulator carries out comparison verification on initially generated data and finally reprocessed data. According to the invention, multi-satellite multi-node signal simulation is realized, signal change states during inter-satellite relative motion are simulated, and closed-loop verification of inter-satellite link uplink and downlink data during satellite ground testing is realized.

Description

Technical Field

[0001] The invention relates to a geostationary orbit remote sensing satellite intersatellite link simulation verification test system and method, belonging to the field of aerospace technology. Background Art

[0002] In the past, intersatellite link subsystems were mostly used in navigation, communication and other fields. In recent years, due to the increase in the use scenarios of remote sensing satellites and the significant improvement in the degree of constellation, intersatellite link subsystems have also begun to be deployed on remote sensing satellites on a large scale. At present, the intersatellite link subsystem of remote sensing satellites is mainly used for communication and data transmission between satellites. Compared with the intersatellite link subsystems of traditional communication and navigation satellites, the intersatellite link transmission data flux of remote sensing satellites is high. Geostationary orbit satellites are usually used as relays or hubs, and other satellites (referred to as other satellites) that communicate with them through intersatellite links have more nodes and higher data flux. At the same time, due to the complexity of remote sensing satellite missions and the large relative motion between satellites, the signal transmission characteristics will change. During the ground whole-satellite test, the verification of the intersatellite link of geostationary orbit remote sensing satellites requires the verification of both the data stream and the radio frequency link. Due to the limitations of the ground whole-satellite test, it is impossible to simulate the on-orbit state in reality. Therefore, during the current remote sensing satellite whole-satellite test, the intersatellite link data stream is mostly limited to single-satellite verification, and the radio frequency link is mostly limited to system verification, lacking a more realistic simulation of multi-satellite, multi-node, and on-orbit state. Summary of the invention

[0003] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art and provide a geostationary orbit remote sensing satellite inter-satellite link simulation verification test system and method, which can realize signal simulation of multiple satellites and multiple nodes, simulation of signal change state during relative motion between satellites, and realize closed-loop verification of inter-satellite link uplink and downlink data during satellite ground testing. The technical solution of the present invention is: A geostationary orbit remote sensing satellite intersatellite link simulation verification test system, comprising: a satellite terminal simulator, a signal generation and transmission module, an intersatellite channel simulator, and a signal reception and processing module; The other satellite terminal simulator simulates and generates other satellite data according to the inter-satellite link data format; The other-satellite data is sent to a signal generating and sending module through a network, and the signal generating and sending module generates a radio frequency other-satellite signal from the other-satellite data according to an inter-satellite link communication protocol, and sends the signal to an inter-satellite channel simulator; The intersatellite channel simulator simulates the time-frequency characteristics of the RF other-satellite signal sent to the satellite, simulates the changes in the time-frequency characteristics of the signal during the movement of the other satellite, and sends the RF other-satellite signal with the time-frequency characteristics added to the intersatellite link receiving device of the satellite; The satellite's inter-satellite link receiving device receives and processes the uplink RF signal from other satellites with time-frequency characteristics, and then outputs it to the signal receiving and processing module on the ground through the inter-satellite link downlink channel; The signal receiving and processing module re-interprets the RF signal into a baseband signal according to the inter-satellite link communication protocol, transmits it back to the other-satellite terminal simulator through the network, and compares and verifies the initially generated data with the final reprocessed data through the other-satellite terminal simulator.

[0004] Furthermore, it also includes a time-frequency reference module for performing system time alignment.

[0005] Furthermore, the intersatellite link data format includes a frame synchronization header, a version number, a spacecraft identifier, a virtual channel identifier, a virtual channel frame count, a flag field, an insertion field, valid data, an error control field, and check data; The valid data carries all the valid data information for inter-satellite interaction with geostationary orbit remote sensing satellites.

[0006] Furthermore, when the signal generation and sending module generates a radio frequency other-satellite signal, if there are other-satellite data of multiple satellites, the radio frequency other-satellite signal of the corresponding satellite is sent out at a specified time according to the inter-satellite link communication protocol, and the time interval is based on the provisions of the inter-satellite link communication protocol.

[0007] Furthermore, the terminal simulator of the other satellite sends the signal of the inter-satellite link in the inter-satellite link data format, can cache various types of business data, realize the framing and deframing of the information format, and realize the comparison between the data sent to the other satellite and the data transmitted by the satellite.

[0008] Furthermore, the signal generation and transmission module encodes, scrambles and modulates the baseband data to generate an intermediate frequency signal, and completes the up-conversion of the intermediate frequency signal of the intersatellite link to a radio frequency signal.

[0009] Furthermore, the intersatellite channel simulator simulates the time-frequency characteristics of the radio frequency other-satellite signal sent to the satellite, and simulates the change of the time-frequency characteristics of the signal during the movement of the other-satellite, specifically: The intersatellite channel simulator calculates the receiving and transmitting status at a specified time based on the coordinates or ephemeris of the receiving and transmitting targets and the satellite attitude, and simulates the physical environment of space; calculates the arrival frequency and arrival time information of the signals received by the geostationary orbit remote sensing satellite from other satellites based on the relevant information; and generates high-precision relative distance and relative speed data between satellites for dynamic signal simulation.

[0010] Furthermore, the signal receiving and processing module completes the down-conversion of the intersatellite link radio frequency signal to the intermediate frequency signal, completes the capture, tracking, demodulation, descrambling, and decoding of the received signal, and reprocesses it into baseband data.

[0011] In a second aspect, the present invention further proposes a test method based on the geostationary orbit remote sensing satellite inter-satellite link simulation verification test system, comprising the following steps: According to the preset inter-satellite link data format, simulate and generate other satellite data; According to the inter-satellite link communication protocol, the satellite data is generated into a radio frequency satellite signal; Simulate the time-frequency characteristics of the radio frequency satellite signal sent to the satellite, simulate the changes in the time-frequency characteristics of the signal during the movement of the satellite, and generate the radio frequency satellite signal with the time-frequency characteristics added; The satellite receives and processes the uplink RF signal from other satellites with time-frequency characteristics, and then outputs it to the ground through the downlink channel of the intersatellite link; On the ground, the RF signal is re-interpreted into a baseband signal according to the inter-satellite link communication protocol, and the satellite data initially generated by the simulation is compared and verified with the final re-interpreted baseband signal.

[0012] Furthermore, during the entire working process, a time-frequency reference device is used to align the system time, and data is sent and received on time according to the intersatellite link communication protocol.

[0013] The beneficial effects of the present invention compared with the prior art are: (1) The present invention realizes a more realistic simulation verification of the uplink and downlink inter-satellite links when there are multiple satellites and multiple nodes in the geostationary orbit remote sensing satellite and the relative motion between the satellites is large.

[0014] (2) The present invention is capable of performing closed-loop verification on inter-satellite uplink and downlink channels, and can effectively verify the correctness of uplink and downlink channel data.

[0015] (3) The present invention reduces the manual judgment process and improves the testing efficiency through automated testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a flow chart of the geostationary orbit remote sensing satellite intersatellite link simulation verification test method of the present invention; Figure 2 It is a principle block diagram of the geostationary orbit remote sensing satellite intersatellite link simulation verification test system of the present invention; Figure 3 This is a schematic diagram of the intersatellite link data format. DETAILED DESCRIPTION

[0017] The specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

[0018] like Figure 2As shown, the present invention proposes a geostationary orbit remote sensing satellite intersatellite link simulation verification test system, including: a satellite terminal simulator, a signal generation and transmission module, an intersatellite channel simulator, a signal receiving and processing module, and a time-frequency reference module; The other satellite terminal simulator simulates and generates other satellite data according to the inter-satellite link data format; The other-satellite data is sent to a signal generating and sending module through a network, and the signal generating and sending module generates a radio frequency other-satellite signal from the other-satellite data according to an inter-satellite link communication protocol, and sends the signal to an inter-satellite channel simulator; The intersatellite channel simulator simulates the time-frequency characteristics of the RF other-satellite signal sent to the satellite, simulates the changes in the time-frequency characteristics of the signal during the movement of the other satellite, and sends the RF other-satellite signal with the time-frequency characteristics added to the intersatellite link receiving device of the satellite; The satellite's inter-satellite link receiving device receives and processes the uplink RF signal from other satellites with time-frequency characteristics, and then outputs it to the signal receiving and processing module on the ground through the inter-satellite link downlink channel; The signal receiving and processing module re-interprets the RF signal into a baseband signal according to the inter-satellite link communication protocol, transmits it back to the other-satellite terminal simulator through the network, and compares and verifies the initially generated data with the final reprocessed data through the other-satellite terminal simulator.

[0019] Time-frequency reference module, used for system time alignment The following is a detailed introduction to each module: a) Other terminal emulators The inter-satellite link signals are sent according to the inter-satellite link data format, which can cache various types of business data, realize the framing and deframing of the information format, and realize the comparison between the data sent to other satellites and the data transmitted by the satellite.

[0020] b) Intersatellite channel simulator Calculate the receiving and transmitting status at a specified time based on the coordinates or ephemeris of the receiving and transmitting targets and the satellite attitude, and simulate the space physical environment (such as time delay). Calculate the arrival frequency and arrival time information of the received signal based on the relevant information. Generate high-precision relative distance and relative speed data between satellites for dynamic signal simulation. Support time management and perform local time maintenance as required.

[0021] c) Signal generation and transmission module The baseband data is framed, encoded, scrambled and modulated to generate an intermediate frequency signal, and the up-conversion of the intermediate frequency signal of the intersatellite link to the radio frequency signal is completed. Considering the power adaptability of each device and the power adaptability of the satellite receiving channel, this part of the equipment may have attenuators and power amplifiers.

[0022] d) Signal receiving and processing module Complete the down-conversion of intersatellite link RF signals to intermediate frequency signals, complete the capture, tracking, demodulation, descrambling, decoding, and deframing of received signals, and reprocess them into baseband data. Considering the power adaptability of each device, this part of the equipment may have attenuators and power amplifiers.

[0023] e) Time-frequency benchmark The time and frequency equipment provides 10MHz clock signal and internal second pulse signal output to maintain the time synchronization of each device in the system; it can accept external pulse signal trigger, and at the same time keep synchronization with external devices by receiving external second pulse signal; it can receive the navigation signal output by the navigation simulator and analyze the time to achieve the unification of system equipment and star time.

[0024] Based on the above-mentioned geostationary orbit remote sensing satellite inter-satellite link simulation verification test system, the present invention proposes a test method as follows Figure 1 As shown, including: Step 1: The satellite terminal simulator generates satellite data according to the inter-satellite link communication protocol and data format.

[0025] The data of other stars of one or more stars can be generated according to the data format requirements.

[0026] like Figure 3 The figure shows the intersatellite link data format, which complies with the AOS (Advanced Orbit System) frame format of CCSDS (International Consultative Committee for Space Data Systems). It includes frame synchronization header, version number, spacecraft identification, virtual channel identification, virtual channel frame count, flag field, insertion field, valid data, error control field, and check data. The valid data area carries various valid data information for intersatellite interaction with geostationary orbit remote sensing satellites.

[0027] Step 2: Send the satellite data to the signal generation module, which generates the satellite signal from the satellite data according to the inter-satellite link communication protocol.

[0028] If there are other satellite data from multiple satellites, the signals of the corresponding satellites need to be sent out at the specified time according to the inter-satellite link communication protocol, and the time interval shall be based on the provisions of the inter-satellite link communication protocol.

[0029] Step 3: The intersatellite channel simulator simulates the time-frequency characteristics of the signal sent to the satellite by the other satellite, simulates the change of the time-frequency characteristics of the signal during the movement of the other satellite, and sends the signal to the satellite intersatellite link receiving device; Step 4: The satellite inter-satellite link receives the uplink signal from other satellites, processes it according to the inter-satellite link data format, and outputs it to the ground signal receiving and processing module through the inter-satellite link downlink channel; Step 5: The ground signal receiving and processing module re-interprets the RF signal into baseband data according to the inter-satellite link communication protocol, and transmits it back to the other-satellite terminal simulator through the network. The other-satellite terminal simulator compares and verifies the initially generated data with the final reprocessed data.

[0030] Parts of the present invention that are not described in detail belong to common knowledge among those skilled in the art.

Claims

1. A geostationary orbit remote sensing satellite intersatellite link simulation verification test system, characterized in that include: Other satellite terminal simulator, signal generation and transmission module, intersatellite channel simulator, signal reception and processing module; The other satellite terminal simulator simulates and generates other satellite data according to the inter-satellite link data format; The other-satellite data is sent to a signal generating and sending module through a network, and the signal generating and sending module generates a radio frequency other-satellite signal from the other-satellite data according to an inter-satellite link communication protocol, and sends the signal to an inter-satellite channel simulator; The intersatellite channel simulator simulates the time-frequency characteristics of the RF other-satellite signal sent to the satellite, simulates the changes in the time-frequency characteristics of the signal during the movement of the other satellite, and sends the RF other-satellite signal with the time-frequency characteristics added to the intersatellite link receiving device of the satellite; The satellite's inter-satellite link receiving device receives and processes the uplink RF signal from other satellites with time-frequency characteristics, and then outputs it to the signal receiving and processing module on the ground through the inter-satellite link downlink channel; The signal receiving and processing module re-interprets the RF signal into a baseband signal according to the inter-satellite link communication protocol, transmits it back to the other-satellite terminal simulator through the network, and compares and verifies the initially generated data with the final reprocessed data through the other-satellite terminal simulator.

2. The geostationary orbit remote sensing satellite intersatellite link simulation verification test system according to claim 1, characterized in that: It also includes a time-frequency reference module for system time alignment.

3. The geostationary orbit remote sensing satellite intersatellite link simulation verification test system according to claim 1, characterized in that: The intersatellite link data format includes a frame synchronization header, a version number, a spacecraft identifier, a virtual channel identifier, a virtual channel frame count, a flag field, an insertion field, valid data, an error control field, and check data; The valid data carries all the valid data information for inter-satellite interaction with geostationary orbit remote sensing satellites.

4. The geostationary orbit remote sensing satellite intersatellite link simulation verification test system according to claim 1, characterized in that: When the signal generation and sending module generates the radio frequency other-satellite signal, if there are other-satellite data of multiple satellites, the radio frequency other-satellite signal of the corresponding satellite will be sent out at the specified time according to the inter-satellite link communication protocol, and the time interval shall be based on the provisions of the inter-satellite link communication protocol.

5. The geostationary orbit remote sensing satellite intersatellite link simulation verification test system according to claim 1, characterized in that: The terminal simulator of the other satellite sends the signal of the inter-satellite link in the inter-satellite link data format, can cache various types of business data, realize the framing and deframing of the information format, and realize the comparison between the data sent to the other satellite and the data transmitted by the satellite.

6. The geostationary orbit remote sensing satellite intersatellite link simulation verification test system according to claim 1, characterized in that: The signal generation and transmission module encodes, scrambles and modulates the baseband data to generate an intermediate frequency signal, and completes the up-conversion of the intermediate frequency signal of the intersatellite link to the radio frequency signal.

7. The geostationary orbit remote sensing satellite intersatellite link simulation verification test system according to claim 1, characterized in that: The intersatellite channel simulator simulates the time-frequency characteristics of the radio frequency other-satellite signal sent to the satellite, and simulates the change of the time-frequency characteristics of the signal during the movement of the other satellite, specifically: The intersatellite channel simulator calculates the receiving and transmitting status at a specified time based on the coordinates or ephemeris of the receiving and transmitting targets and the satellite attitude, and simulates the physical environment of space; calculates the arrival frequency and arrival time information of the signals received by the geostationary orbit remote sensing satellite from other satellites based on the relevant information; and generates high-precision relative distance and relative speed data between satellites for dynamic signal simulation.

8. The geostationary orbit remote sensing satellite inter-satellite link simulation verification test system according to claim 1, characterized in that: The signal receiving and processing module completes the down-conversion of the intersatellite link RF signal to the intermediate frequency signal, completes the capture, tracking, demodulation, descrambling and decoding of the received signal, and reprocesses it into baseband data.

9. A test method based on the geostationary orbit remote sensing satellite inter-satellite link simulation verification test system according to any one of claims 1 to 8, characterized in that include: According to the preset inter-satellite link data format, simulate and generate other satellite data; According to the inter-satellite link communication protocol, the satellite data is generated into a radio frequency satellite signal; Simulate the time-frequency characteristics of the radio frequency satellite signal sent to the satellite, simulate the changes in the time-frequency characteristics of the signal during the movement of the satellite, and generate the radio frequency satellite signal with the time-frequency characteristics added; The satellite receives and processes the uplink RF signal from other satellites with time-frequency characteristics, and then outputs it to the ground through the downlink channel of the intersatellite link; On the ground, the RF signal is re-interpreted into a baseband signal according to the inter-satellite link communication protocol, and the satellite data initially generated by the simulation is compared and verified with the final re-interpreted baseband signal.

10. The testing method according to claim 9, characterized in that: During the entire working process, time and frequency reference equipment is used to align the system time, and data is sent and received on time according to the intersatellite link communication protocol.

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