Reentry return spacecraft's TT&C, beacon carrier device and its verification system and method

Abstract

The application relates to a control and demonstration device of a reentry return spacecraft, and a verification system and method thereof, and belongs to the technical field of deep space exploration control. The device is carried on a reentry return spacecraft of the earth, receives navigation signals broadcast by a satellite navigation system, realizes spacecraft positioning and speed measurement, establishes a communication link with a Beidou system through a Beidou short message, forms a Beidou short message communication group with multiple ground users, the device and the ground users are group terminals, and the group number and the terminal number distributed by the Beidou system are used for identity identification; the device realizes communication with the ground users through the short message service provided by the Beidou system, including that the device sends spacecraft information to the Beidou system, the group number is explicitly indicated in the format of the spacecraft information, the Beidou system forwards the spacecraft information to all group terminals in the group through a short message outbound signal; after positioning is completed, the device sends spacecraft position information to the group through the Beidou short message service; the ground users send spacecraft remote control to the Beidou system, the terminal number of the device is explicitly indicated in the format of the remote control information, and the Beidou system forwards the spacecraft remote control to the device through a short message outbound signal.

Description

Technical Field

[0001] This invention belongs to the field of deep space exploration telemetry and control technology, specifically relating to the telemetry and control of reentry and return spacecraft, the onboard device for the position indicator, and its verification system and method. Background Technology

[0002] Telemetry and remote control, along with position acquisition, are the main functional requirements of onboard telemetry and control equipment for reentry and return space missions, and are crucial for the successful implementation of the mission. The former enables ground flight control personnel to monitor the status of the probe and issue commands, while the latter provides ground recovery personnel with the accurate position of the spacecraft.

[0003] Currently, only NASA (Stardust and OSIRIS-Rex missions) and JAXA (Hayabusa and Hayabusa-2 missions) have conducted reentry and return missions involving payloads in the tens of kilograms range. Due to limitations in probe resources, these missions all relied on spacecraft sending beacons to guide recovery personnel in the search. There was no communication throughout the reentry and recovery process, and ground control personnel could not monitor or control the spacecraft. Furthermore, the recovery beacons could only indicate the relative position between the spacecraft and the recovery personnel, not the precise location. Therefore, the reliability and timeliness of these missions were relatively low. Summary of the Invention

[0004] The technical problem solved by this invention is to address the shortcomings of traditional methods for communication and positioning of reentry spacecraft via ground-based telemetry, tracking, and recovery equipment. This invention proposes a telemetry, tracking, and positioning device for reentry spacecraft, along with its verification system and method, enabling communication and positioning below the visible elevation angle of the ground station, as well as real-time distribution of the spacecraft's position. This effectively improves mission performance and reliability.

[0005] The solution of this invention is: a telemetry, tracking, and command (TT&C) and positioning device for a reentry spacecraft. This device is mounted on the Earth reentry spacecraft and achieves spacecraft positioning and velocity measurement by receiving navigation signals broadcast by a satellite navigation system. It establishes a communication link with the BeiDou system via BeiDou short message service and forms BeiDou short message communication groups with multiple ground users. Both the device and the ground users are group terminals, identified by group numbers and terminal numbers assigned by the BeiDou system. The device communicates with ground users through the short message service provided by the BeiDou system, including: the device sending spacecraft information to the BeiDou system, with the group number explicitly specified in the information format; the BeiDou system forwarding the spacecraft information to all group terminals within the group via a short message outgoing signal; after completing positioning, the device sending the spacecraft position information to the group via the BeiDou short message service; and ground users sending spacecraft remote control information to the BeiDou system, with the device's terminal number explicitly specified in the remote control information format; the BeiDou system forwarding the remote control information to the device via a short message outgoing signal.

[0006] Preferably, the telemetry, tracking, and positioning equipment of the reentry spacecraft includes an antenna and a reentry communication positioning device; The antenna is used to receive navigation signals and short message signals out of the station and to transmit short message signals into the station. The reentry and return communication positioning device is used to demodulate navigation signals to complete spacecraft positioning and velocity measurement, demodulate short message outgoing signals to obtain information sent from the ground to the spacecraft, and modulate spacecraft telemetry information and positioning and velocity measurement information to generate short message incoming signals and output them.

[0007] Preferably, the antenna adopts a shared transmit and receive design, using a single antenna to receive navigation signals and short message outbound signals, as well as transmit short message inbound signals.

[0008] Preferably, there are two antennas arranged in a dual-antenna array to achieve sufficient airspace coverage and ensure that the number of visible navigation satellites during reentry and recovery meets at least the basic positioning requirements.

[0009] Preferably, the two antennas have the same beam angle, which is determined by the following method: S1.1, Based on the nominal start time of the spacecraft's reentry and return... The earliest time is The latest time is Determine the simulation analysis time. At least including , , ; exist and between, Take the earliest time, Take the latest time.

[0010] S1.2, Based on the nominal rotational speed at the start of spacecraft reentry and return... Minimum speed is Maximum speed is Determine the aerospace rotation speed in the simulation analysis , including at least , , ; S1.3 Determine the simulation set based on different combinations of time and rotational speed. There are a total of m×n simulation conditions, where different simulation conditions correspond to different simulation start times, navigation constellation distributions, and spacecraft reentry and return trajectories; S1.4. Conduct simulations for m×n different operating conditions, using the minimum number of visible stars as the simulation constraint, and determine the minimum beam angles of the two antennas for each operating condition. The simulation results are as follows: The maximum value among them is taken as the antenna beam angle.

[0011] Preferably, the outbound communication frequency of the onboard device ,in, This refers to the amount of data that needs to be sent to the spacecraft per unit of time. The length of the communication message.

[0012] Preferably, the telemetry code rate of the onboard device ,in, This represents the amount of telemetry data that a spacecraft needs to transmit per unit of time.

[0013] Another technical solution of the present invention is: a verification system for the telemetry, tracking and command and position indicator onboard device of a reentry spacecraft, the system including a navigation signal simulator, a short message simulator and a ground test computer for the onboard device under test; The navigation signal simulator dynamically simulates the navigation constellation and its output navigation signals based on the antenna gain diagram and spacecraft trajectory, and outputs satellite navigation signals to the onboard device under test. The short message simulator simulates the BeiDou navigation constellation and its outgoing signals based on the antenna gain diagram and spacecraft orbit, outputs short message outgoing signals to the device under test, and receives short message incoming signals from the device under test. The ground test computer of the device under test receives navigation and positioning information and short message communication information output by the device under test, and completes the performance index test of the device under test.

[0014] Preferably, the performance indicators include navigation signal receiving sensitivity, positioning time accuracy, positioning accuracy, speed measurement accuracy; short message sensitivity, acquisition time, communication frequency, and transmission frequency accuracy.

[0015] Another technical solution of the present invention is: a verification method for the telemetry, tracking and positioning device of a reentry spacecraft. The method involves conducting acquisition performance tests and tracking performance tests under nominal operating conditions and deflection operating conditions, respectively. The nominal operating condition refers to the test trajectory being the reentry and return trajectory of the spacecraft, and the deflection operating condition refers to the test trajectory covering the maximum on-orbit velocity, maximum acceleration, and maximum jerk. The specific steps for capturing performance testing are as follows: S1a. Extract two characteristic arc segments from the test track, one of which covers the maximum on-orbit speed and the other covers the maximum acceleration and maximum jerk. The duration of each characteristic arc segment meets the single-machine cold start capture index test requirements. The S1b, navigation signal simulator, and short message simulator are loaded with the maximum speed characteristic arc segment, and the power is switched on and off at timed intervals by a programmable power supply. The power-on and power-off intervals are matched with the duration of the characteristic arc segment. The acquisition performance test of the device under test is repeated until the number of tests meets the requirements. The test results of the performance indicators are statistically analyzed by the ground test computer of the device under test. The S1c, navigation signal simulator, and short message simulator are loaded with maximum acceleration and maximum jerk characteristic arcs. The power is switched on and off at timed intervals by a programmable power supply, with the power-on and power-off intervals matching the duration of the characteristic arcs. The acquisition performance test of the device under test is repeated until the number of tests meets the requirements. The test results of the performance indicators are statistically analyzed by the ground test computer of the device under test. The tracking performance test process is as follows: the navigation signal simulator and the short message simulator load the test track, and the test track runs repeatedly until the test time meets the test requirements. During this period, the device under test is powered on and the performance index test results are statistically analyzed by the ground test computer of the device under test.

[0016] The advantages of this invention compared to the prior art are: (1) Compared with the existing reentry and return missions of tens of kilograms, the present invention has real-time communication and position marking functions, which solves the problem of ground flight control personnel monitoring and controlling the spacecraft in real time, as well as the problem of ground recovery personnel directly obtaining the spacecraft's position (including speed information).

[0017] (2) This invention utilizes the space-based communication provided by the Beidou short message system to avoid the elevation angle constraint of ground-based measurement and control equipment, realize communication before and after landing, and improve the utilization rate of onboard equipment.

[0018] (3) This invention realizes multi-point communication through the group communication function of the short message system, which has higher task reliability and timeliness compared with traditional point-to-point communication.

[0019] (4) This invention solves the problem that high dynamic scenes cannot be reproduced on a one-to-one scale on the ground. The performance indicators of the device are qualitatively evaluated through semi-physical simulation verification tests. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the link in an embodiment of the present invention.

[0021] Figure 2 This is a block diagram of a reentry return communication positioning device according to an embodiment of the present invention.

[0022] Figure 3 This is a block diagram of the semi-physical simulation verification test connection according to an embodiment of the present invention. Detailed Implementation

[0023] The present invention will be further described below with reference to the embodiments.

[0024] To address the adverse effects of high dynamics on signal reception and processing in reentry and recovery channels, as well as the objective constraints such as limited spacecraft-ground telemetry, tracking, and command (TT&C) resources, this invention proposes an integrated TT&C and positioning system-based onboard equipment and a high-dynamic scenario verification method. This method supports on-orbit missions for reentry and recovery spacecraft, particularly for lightweight return capsules weighing tens of kilograms. While meeting mission requirements, the proposed device and method effectively conserve spacecraft-ground resources and improve mission efficiency and reliability through multi-point communication.

[0025] This invention proposes a high-dynamic reentry and return communication positioning device and verification method, which supports spacecraft to complete self-positioning through a navigation system and transmit data through a space-based (BeiDou short message system) communication channel, thus realizing both communication and positioning functions.

[0026] Using space-based facilities to complete telemetry and control missions avoids ground elevation angle constraints compared to using ground-based facilities, and allows for visibility of the arc segment before and after landing, effectively increasing the working time of onboard equipment.

[0027] In particular, this invention proposes to utilize the BeiDou short message group communication function to achieve multi-point communication, which has higher reliability and timeliness compared to point-to-point communication of ground-based telemetry and control and space-based telemetry and control (such as Tianlian). Furthermore, since ground-based physical testing cannot perfectly replicate the high-speed process of high-dynamic reentry and return, this paper proposes a testing method based on semi-physical simulation verification.

[0028] like Figure 1As shown, this invention provides a telemetry, tracking, and command (TT&C) and positioning device for a reentry and return spacecraft. The device is mounted on the Earth reentry and return spacecraft and achieves spacecraft positioning and velocity measurement by receiving navigation signals broadcast by a satellite navigation system. It establishes a communication link with the BeiDou system via BeiDou short message service and forms BeiDou short message communication groups with multiple ground users. Both the device and the ground users are group terminals, identified by group numbers and terminal numbers assigned by the BeiDou system. The device communicates with ground users through the short message service provided by the BeiDou system, including: the device sending spacecraft information to the BeiDou system, with the group number explicitly specified in the information format; the BeiDou system forwarding the spacecraft information to all group terminals within the group via a short message outgoing signal; after completing positioning, the device sending the spacecraft position information to the group via the BeiDou short message service; and ground users sending spacecraft remote control information to the BeiDou system, with the device's terminal number explicitly specified in the remote control information format; the BeiDou system forwarding the spacecraft remote control to the device via a short message outgoing signal.

[0029] The following section provides a detailed introduction to the device's operating mode, device performance design methods, and device verification methods.

[0030] 1. Device Operation Mode The device proposed in this invention can realize three functions: communication between the reentry and return spacecraft and ground users, spacecraft positioning, and real-time distribution of spacecraft position. The steps for realizing the above functions are as follows: 1) Spacecraft-to-Ground User Communication The device communicates with ground users via the short message service provided by the BeiDou system. Each ground user can be a separate user. The ground users and the device form a BeiDou short message communication group (hereinafter referred to as group terminals), and the BeiDou system assigns a group number as an identification identifier. Group formation, group number assignment, and terminal number allocation are public services of the BeiDou system and are not described in this invention.

[0031] Before any group of terminals can communicate, they need to establish a communication link with the BeiDou system (referred to as link establishment). Therefore, communication between group terminals includes two steps: link establishment and sending and receiving information.

[0032] 2) The device communication steps are as follows: (1) Link Establishment. Once the device enters the short message communication service range of the BeiDou system, it selects the optimal communication beam to establish a link with the BeiDou system based on the signal strength of different short message communication beams received. After the link is established, the spacecraft completes information transmission and reception through the device; (2) Spacecraft transmits information. The device transmits spacecraft information to the BeiDou system, specifying the group number in the information format. The BeiDou system forwards this information to all terminals within the group; (3) Spacecraft receiving information. The BeiDou system receives information sent to the device by ground users and forwards the information to the device. The short message terminal number of the device must be clearly specified in the information format.

[0033] 2) Spacecraft positioning The device achieves spacecraft positioning by receiving navigation signals broadcast by navigation systems (such as BeiDou, GPS, GLOASS, and Galileo). The positioning method is a mature technology used in both military and civilian applications, and will not be described in this invention.

[0034] 3) Spacecraft location distribution After the device completes its positioning, it sends the spacecraft's location information to the group via a communication link.

[0035] 4) Device Composition like Figure 2 As shown, the aforementioned onboard device consists of two antennas and a reentry / return communication positioning device. The antennas are used to receive navigation signals and short message signals outbound and to transmit short message signals inbound. The reentry and return communication positioning device is used to demodulate navigation signals to complete spacecraft positioning and velocity measurement, demodulate short message outgoing signals to obtain information sent from the ground to the spacecraft, and modulate spacecraft telemetry information and positioning and velocity measurement information to generate short message incoming signals and output them.

[0036] Considering that the spacecraft may obstruct the antenna gain pattern, a dual-antenna array is adopted to achieve sufficient airspace coverage and ensure that the number of visible navigation satellites during reentry and recovery meets at least the basic positioning requirements.

[0037] The antenna adopts a shared transmit and receive design, using a single antenna to receive navigation signals and short message outbound signals, as well as transmit short message inbound signals.

[0038] The reentry and return communication positioning device possesses navigation and positioning (including velocity measurement) and short message communication functions. The navigation and positioning function involves receiving navigation messages broadcast by the navigation constellation via an antenna to measure the spacecraft's position and velocity. The short message function comprises two parts: link establishment and communication. Once the reentry and return communication positioning device establishes a short message link with the BeiDou satellite, it can transmit spacecraft telemetry information and receive remote control information via the short message link. The spacecraft's position (including velocity) information is also transmitted along with the telemetry information via the short message inbound link.

[0039] Ground users and the device form a BeiDou short message communication group, with the BeiDou system assigning a group number as the group identifier. When ground users send spacecraft remote control information, the destination address is the short message terminal number corresponding to the device; when the device sends spacecraft telemetry and position (including velocity) information, the destination address is the group identifier, and all users within the group can receive the corresponding information.

[0040] 2. Equipment Specification Design Method (1) Antenna coverage design Antenna coverage analysis based on the spacecraft's reentry and return trajectory and navigation constellation distribution requires ensuring a sufficient number of navigation satellites during reentry and recovery. Specifically, at least one satellite should support short message communication; and at least four or five navigation and positioning satellites should be supported. When using a single navigation constellation (such as BeiDou or GPS) for spacecraft positioning, at least four satellites are required. When using a dual navigation constellation (BeiDou and GPS) for joint positioning, at least five satellites are required.

[0041] The specific analysis steps are as follows: S1.1, Based on the nominal start time of the spacecraft's reentry and return... The earliest time is The latest time is Determine the simulation analysis time. At least including , , ; exist and between, Take the earliest time, Take the latest time.

[0042] S1.2, Based on the nominal rotational speed at the start of spacecraft reentry and return... Minimum speed is The maximum speed is That is, the speed range is Determine the aerospace rotation speed in the simulation analysis , including at least , , ; If the spacecraft does not undergo spin reentry, the rotational speed is taken as 0.

[0043] S1.3 Determine the simulation set based on different combinations of time and rotational speed. There are a total of m×n simulation conditions, where different simulation conditions correspond to different simulation start times, navigation constellation distributions, and spacecraft reentry and return trajectories; S1.4. Conduct simulations for m×n different operating conditions, using the minimum number of visible stars as the simulation constraint, and determine the minimum beam angles of the two antennas for each operating condition. The simulation results are as follows: The maximum value among them is taken as the antenna beam angle.

[0044] (2) Analysis of outbound signals The BeiDou Navigation Short Message Communication System limits the frequency of outbound communication for users ( ), code rate ( ) and message length ( All of these are stipulated. During the device design process, the requirements of the aerospace mission and the relevant regulations of the BeiDou Navigation Short Message System should be considered.

[0045] Based on antenna coverage parameters, antenna layout, and spacecraft surface conditions, complete the antenna optimization design and determine its minimum receiving gain. ); Conducting link budget analysis, using indicators of the BeiDou system navigation and short message communication interfaces, as well as the spacecraft reentry and return trajectory (including spacecraft attitude rotation) and the minimum receiving gain of the antenna (…). ), computing device received power ( ); According to the power received by the device ( ) and remote control error rate requirements (generally taken as 1×10) -5 Determine the highest remote control code rate that the link can support. Based on the inbound code rate specifications stipulated by the BeiDou short message system, the spacecraft inbound remote control code rate is determined. ,Require

[0046] Based on the requirements of the on-orbit mission, determine the amount of data that needs to be sent to the spacecraft per unit time (usually chosen as seconds). In order to obtain the communication frequency .

[0047] (3) Inbound signal analysis The BeiDou Navigation Short Message Communication System limits the frequency of inbound communication with users. ), code rate ( ) and message length ( There are also regulations. During the device design process, the requirements of the space mission and the relevant regulations of the BeiDou Navigation Short Message System must also be considered.

[0048] Based on antenna coverage parameters, antenna layout, and spacecraft surface conditions, complete the antenna optimization design and determine its minimum transmit gain. ); Based on the requirements of the on-orbit mission, determine the amount of telemetry data that the spacecraft needs to transmit per unit time (usually chosen as seconds). In order to obtain the communication frequency ; Based on telemetry data volume (Unit: seconds) and telemetry bit error rate requirement (generally taken as 1×10) -5Link budget analysis was conducted, specifically using indicators of the BeiDou system's short message communication interface, as well as the spacecraft's reentry and return trajectory (including spacecraft rotation) and the minimum transmit gain of the antenna. Average output power of computing device ( ); Based on the outbound code rate specified by the BeiDou short message system, the spacecraft telemetry code rate is determined. ,Require ,in, This refers to the amount of telemetry data that the spacecraft needs to send.

[0049] 3. Device Verification System During spacecraft reentry and return, the mission adaptability verification of the device can be achieved by building a semi-physical simulation verification platform using the reentry and return communication positioning device and navigation signal and short message signal simulators. Both the navigation signal and short message signal simulators are general-purpose ground testing equipment (the former can be a Spirent 9000 series simulator, and the latter can be a Hunan Matrix Electronics GNS8340 simulator). It is important to note that during the semi-physical simulation verification, actual antenna products are not used; instead, the measured gain pattern of the antenna is substituted.

[0050] like Figure 3 As shown, the semi-physical simulation test consists of the device under test (DUT), a navigation signal simulator, a short message simulator, and a ground-based test computer for the DUT. During the test: The navigation signal simulator dynamically simulates the navigation constellation and its broadcast navigation signals based on the antenna gain diagram (measured gain pattern or simulated gain pattern) and the spacecraft trajectory, and outputs the satellite navigation signal to the device under test. The short message simulator dynamically simulates the BeiDou navigation constellation and its outgoing signals based on the antenna gain diagram and spacecraft orbit, outputs short message outgoing signals to the device under test, and receives short message incoming signals from the device under test. The ground-based test computer of the device under test receives navigation and positioning information (including speed) and short message communication information output by the device under test, and completes the performance index test of the device under test.

[0051] The performance indicators include navigation signal receiving sensitivity, positioning time accuracy, positioning accuracy, velocity measurement accuracy; short message sensitivity, acquisition time, communication frequency, and transmission frequency accuracy.

[0052] 4. Device Validation Methods The verification method for the telemetry, tracking, and positioning devices of reentry spacecraft includes conducting acquisition performance tests and tracking performance tests under nominal operating conditions and pull-off operating conditions, respectively.

[0053] The test conditions include the nominal condition and the yaw condition. The spacecraft trajectory used in the nominal condition (test trajectory) is the spacecraft reentry and return trajectory (including spacecraft attitude rotation). The test trajectory in the yaw condition covers the maximum on-orbit velocity, maximum acceleration, and maximum jerk. The maximum on-orbit velocity, maximum acceleration, and maximum jerk involved in the yaw condition are obtained through target simulation during the reentry and return process, and a high-dynamic test trajectory is designed to cover these parameters; this will be referred to as the test trajectory below.

[0054] The pull-off test includes two stages: capture performance test and tracking performance test (burn-in test) to verify whether the device performance indicators meet the usage requirements.

[0055] S1a. Extract two characteristic arc segments from the test track, one of which covers the maximum on-orbit speed and the other covers the maximum acceleration and maximum jerk. The duration of each characteristic arc segment meets the single-machine cold start capture index test requirements. The S1b, navigation signal simulator, and short message simulator are loaded with the maximum speed characteristic arc segment, and the power is switched on and off at timed intervals by a programmable power supply. The power-on and power-off intervals are matched with the duration of the characteristic arc segment. The acquisition performance test of the device under test is repeated until the number of tests meets the requirements. The test results of the performance indicators are statistically analyzed by the ground test computer of the device under test. The S1c, navigation signal simulator, and short message simulator are loaded with maximum acceleration and maximum jerk characteristic arcs. The power is switched on and off at timed intervals by a programmable power supply, with the power-on and power-off intervals matching the duration of the characteristic arcs. The acquisition performance test of the device under test is repeated until the number of tests meets the requirements. The test results of the performance indicators are statistically analyzed by the ground test computer of the device under test. The tracking performance test process is as follows: the navigation signal simulator and the short message simulator load the test track, and the test track runs repeatedly until the test time meets the test requirements. During this period, the device under test is powered on and the performance index test results are statistically analyzed by the ground test computer of the device under test.

[0056] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A telemetry, tracking, and positioning device for a reentry spacecraft, characterized in that, The onboard device is carried on the Earth reentry and return spacecraft. It achieves spacecraft positioning and velocity measurement by receiving navigation signals broadcast by the satellite navigation system. It establishes a communication link with the BeiDou system through BeiDou short message service and forms BeiDou short message communication groups with multiple ground users. Both the onboard device and the ground users are group terminals, and their identities are identified by the group number and terminal number assigned by the BeiDou system. The onboard device communicates with ground users through the short message service provided by the BeiDou system, including: the onboard device sending spacecraft information to the BeiDou system, the spacecraft information format specifying the group number; the BeiDou system forwarding the spacecraft information to all group terminals within the group via short message outbound signal; after the onboard device completes positioning, it sends the spacecraft location information to the group via the BeiDou short message service. Ground users send remote control information for spacecraft to the BeiDou system. The remote control information format clearly specifies the onboard terminal number. The BeiDou system then forwards the remote control information to the onboard device via a short message outbound signal.

2. The telemetry, tracking, and positioning device for a reentry spacecraft according to claim 1, characterized in that, Includes antenna and reentry / return communication positioning device; The antenna is used to receive navigation signals and short message signals out of the station and to transmit short message signals into the station. The reentry and return communication positioning device is used to demodulate navigation signals to complete spacecraft positioning and velocity measurement, demodulate short message outgoing signals to obtain information sent from the ground to the spacecraft, and modulate spacecraft telemetry information and positioning and velocity measurement information to generate short message incoming signals and output them.

3. The telemetry, tracking, and positioning device for a reentry spacecraft according to claim 1, characterized in that, The antenna adopts a shared transmit and receive design, using a single antenna to receive navigation signals and short message outbound signals, as well as transmit short message inbound signals.

4. The telemetry, tracking, and positioning device for a reentry spacecraft according to claim 1, characterized in that, The antenna consists of two pairs, arranged in a dual-antenna array to achieve sufficient airspace coverage and ensure that the number of visible navigation satellites during reentry and recovery meets at least the basic positioning requirements.

5. The telemetry, tracking, and positioning device for a reentry spacecraft according to claim 4, characterized in that, The two antennas have the same beam angle, which is determined by the following method: S1.1, Based on the nominal start time of the spacecraft's reentry and return... The earliest time is The latest time is Determine the simulation analysis time. At least including , , ; exist and between, Take the earliest time, Take the latest time. S1.2, Based on the nominal rotational speed at the start of spacecraft reentry and return... Minimum speed is Maximum speed is Determine the aerospace rotation speed in the simulation analysis , including at least , , ; S1.3 Determine the simulation set based on different combinations of time and rotational speed. There are a total of m×n simulation conditions, where different simulation conditions correspond to different simulation start times, navigation constellation distributions, and spacecraft reentry and return trajectories; S1.

4. Conduct simulations for m×n different operating conditions, using the minimum number of visible stars as the simulation constraint, and determine the minimum beam angles of the two antennas for each operating condition. The simulation results are as follows: The maximum value among them is taken as the antenna beam angle.

6. The telemetry, tracking, and positioning device for a reentry spacecraft according to claim 1, characterized in that, The outbound communication frequency of the onboard device ,in, This refers to the amount of data that needs to be sent to the spacecraft per unit of time. The length of the communication message.

7. The telemetry, tracking, and positioning device for a reentry spacecraft according to claim 1, characterized in that, The telemetry code rate of the onboard device ,in, This represents the amount of telemetry data that a spacecraft needs to transmit per unit of time.

8. The verification system for the telemetry, tracking, and positioning device of a reentry spacecraft according to claim 1, characterized in that, This includes navigation signal simulators, short message simulators, and ground test computers for onboard devices under test; The navigation signal simulator dynamically simulates the navigation constellation and its output navigation signals based on the antenna gain diagram and spacecraft trajectory, and outputs satellite navigation signals to the onboard device under test. The short message simulator simulates the BeiDou navigation constellation and its outgoing signals based on the antenna gain diagram and spacecraft orbit, outputs short message outgoing signals to the device under test, and receives short message incoming signals from the device under test. The ground test computer of the device under test receives navigation and positioning information and short message communication information output by the device under test, and completes the performance index test of the device under test.

9. The verification system for the telemetry, tracking, and positioning device of a reentry spacecraft according to claim 8, characterized in that, The performance indicators include navigation signal receiving sensitivity, positioning time accuracy, positioning accuracy, velocity measurement accuracy; short message sensitivity, acquisition time, communication frequency, and transmission frequency accuracy.

10. A verification method for the telemetry, tracking, and positioning device of a reentry spacecraft based on the system described in claim 8 or 9, characterized in that, Acquisition performance and tracking performance were tested under the nominal operating condition and the pull-off operating condition, respectively. The nominal operating condition refers to the test trajectory being the spacecraft's reentry and return trajectory, while the pull-off operating condition refers to the test trajectory covering the maximum on-orbit velocity, maximum acceleration, and maximum jerk. The specific steps for capturing performance testing are as follows: S1a. Extract two characteristic arc segments from the test track, one of which covers the maximum on-orbit speed and the other covers the maximum acceleration and maximum jerk. The duration of each characteristic arc segment meets the single-machine cold start capture index test requirements. The S1b, navigation signal simulator, and short message simulator are loaded with the maximum speed characteristic arc segment, and the power is switched on and off at timed intervals by a programmable power supply. The power-on and power-off intervals are matched with the duration of the characteristic arc segment. The acquisition performance test of the device under test is repeated until the number of tests meets the requirements. The test results of the performance indicators are statistically analyzed by the ground test computer of the device under test. The S1c, navigation signal simulator, and short message simulator are loaded with maximum acceleration and maximum jerk characteristic arcs. The power is switched on and off at timed intervals by a programmable power supply, with the power-on and power-off intervals matching the duration of the characteristic arcs. The acquisition performance test of the device under test is repeated until the number of tests meets the requirements. The test results of the performance indicators are statistically analyzed by the ground test computer of the device under test. The tracking performance test process is as follows: the navigation signal simulator and the short message simulator load the test track, and the test track runs repeatedly until the test time meets the test requirements. During this period, the device under test is powered on and the performance index test results are statistically analyzed by the ground test computer of the device under test.

Images