Sounding rocket ground telemetry system design method

Abstract

The invention discloses a sounding rocket ground telemetering system design method, which comprises the following steps of: performing simulation calculation on a communication link according to a link standard of sounding rocket data transmission data in combination with trajectory simulation data of a sounding rocket; determining a communication demand and a tracking demand according to trajectory simulation data, selectable site data and rocket-borne antenna transmitting and receiving characteristic data of the sounding rocket; according to a communication demand and a tracking demand, determining an antenna index of the sounding rocket ground telemetry system, and designing an antenna layout scheme; and according to the antenna layout scheme, carrying out simulation analysis on the factors of the sounding rocket ground telemetering system influencing the communication link quality, judging whether the sounding rocket ground telemetering system meets the sounding rocket task requirements or not, and completing the sounding rocket ground telemetering system. The sounding rocket ground telemetering system scheme realized by adopting the design of the invention meets data transmission tracking and receiving requirements of sounding rocket data tasks at the midnight second stage, and realizes reliable communication of sounding rockets under limited site distribution sites.

Description

Technical Field

[0001] The invention belongs to the technical field of ground measurement, control and data transmission of sounding rockets, and in particular relates to a design method for a ground telemetry system of a sounding rocket. Background Art

[0002] Sounding rockets have the characteristics of high flight altitude and short flight time. At the same time, they are affected by factors such as the shielding of the rocket body, the characteristics of the antenna pattern on the rocket, and the limited resources of the station location, so data reception may have potential risks. Currently, there is a lack of research on the design method of the ground telemetry system of sounding rockets in publicly published literature. Sounding rockets can penetrate into the middle and upper atmosphere and conduct vertical detection of the structural components and parameters of each layer of the atmosphere, which is crucial for understanding the changes in the atmospheric environment, the geomagnetic field and other solar-terrestrial physical phenomena. Ground telemetry during the launch of sounding rockets faces unique and complex technical challenges. The high-speed flight trajectory of sounding rockets is constantly changing, and the flight speed and acceleration change rapidly, resulting in unstable communication links and signals that are susceptible to interference. There are concave areas in the rocket antenna pattern, and the shielding of the rocket body itself further increases the difficulty of data transmission. At the same time, the rapid changes in the attitude and position of the sounding rocket place extremely high demands on the accuracy and response speed of the ground tracking system. How to ensure the continuity, integrity and reliability of telemetry data in such a dynamic and complex environment has become a key issue that needs to be solved urgently. This not only involves communication technology, but also requires consideration of ballistic characteristics, antenna design, signal processing and other aspects. Failure to effectively address these challenges will directly affect the success rate of launch missions and the quality of scientific data acquisition. Summary of the invention

[0003] The purpose of the present invention is to overcome the defects of the prior art and propose a design method for a ground telemetry system of a sounding rocket.

[0004] In view of this, the present invention proposes a design method for a sounding rocket ground telemetry system, comprising:

[0005] According to the link standard of the sounding rocket digital transmission data, combined with the ballistic simulation data of the sounding rocket, the communication link is simulated and calculated;

[0006] Determine the communication and tracking requirements based on the sounding rocket's trajectory simulation data, optional site data, and the launch and receiving characteristics of the rocket-borne antenna;

[0007] Determine the antenna specifications of the sounding rocket ground telemetry system and design the antenna layout plan based on communication and tracking requirements;

[0008] According to the antenna layout plan, the factors affecting the communication link quality of the sounding rocket ground telemetry system are simulated and analyzed to determine whether the sounding rocket ground telemetry system meets the sounding rocket mission requirements and complete the sounding rocket ground telemetry system.

[0009] Preferably, the simulation calculation of the communication link includes: the maximum link distance between the sounding rocket and the launch site and the observation station respectively.

[0010] Preferably, the communication requirements include: maximum link distance of optional transmitting sites and / or observation stations, arrow-borne EIRP, data transmission rate, coding method and modulation method.

[0011] Preferably, the number of the observation stations is greater than or equal to one.

[0012] Preferably, the tracking requirements include: the range of azimuth angle θ and pitch angle φ of the sounding rocket and the optional launch site and / or observation station in the ionosphere and thermosphere, azimuth velocity ω and acceleration α, pitch velocity ρ and acceleration β; wherein,

[0013]

[0014] Here, t represents the time.

[0015] Preferably, the antenna indicators of the sounding rocket ground telemetry system include: meeting the signal tracking and reception requirements of the sounding rocket from launch to landing in the sea, and the communication frequency band, maximum data rate, supported communication modulation mechanism and data reception bit error rate all meet the set requirements.

[0016] Preferably, the antenna deployment plan includes: combining the effects of distance, vegetation and terrain on communication channels, and designing the antenna type, deployment location, deployment method, signal capture and tracking method and quantity for each optional site, wherein the antenna types include: wide-beam helical antenna, medium-gain array antenna, high-gain parabolic antenna and parabolic self-tracking antenna, the deployment location is a transmitting site or an observation station, the deployment method is mobile or fixed, and the signal capture and tracking methods include: initial locking, crossing capture and self-tracking.

[0017] Preferably, the simulation analysis of factors affecting the communication link quality of the sounding rocket ground telemetry system according to the antenna layout scheme includes:

[0018] According to the sounding rocket trajectory simulation data and the launch characteristics of the rocket-borne antenna, the signal strength at the ground station receiving antenna during the flight of the sounding rocket is calculated to obtain the link margin of the sounding rocket ground telemetry system.

[0019] According to the characteristics of the antenna pattern on the rocket, it is determined whether the ground station is in the concave area of ​​the rocket antenna during the flight of the sounding rocket;

[0020] According to the sounding rocket trajectory simulation data, determine whether the ground station's line of sight is blocked by the rocket body during the flight of the sounding rocket;

[0021] According to the sounding rocket trajectory simulation data and the characteristics of the rocket-borne antenna pattern, the influence of the sounding rocket attitude change on the ground station tracking reception is analyzed;

[0022] Wherein, the ground station includes a launch site and an observation station.

[0023] Compared with the prior art, the advantages of the present invention are:

[0024] The present invention aims at the sounding rocket mission, and the existing ground telemetry stations cannot realize the full-link tracking mission, so a ground telemetry system scheme design method is proposed. The method of the present invention is used in the two sounding rockets in the ionosphere and thermosphere of the Meridian Project Phase II, and the sounding rocket launch system indicators, rocket trajectory simulation data and optional station sites are used as input. By analyzing the communication and tracking requirements, multiple types of antenna distribution receiving communication arcs are set to cover the full-link tracking reception from pre-launch and rocket erection stage testing, ignition, initial flight, key arcs to landing in the sea, and a ground telemetry system design scheme is proposed. Finally, the system's link margin, antenna concave area, rocket body shielding, attitude control and other influencing factors are simulated and analyzed. The simulation analysis results show that the sounding rocket ground telemetry system scheme designed and implemented by the method of the present invention meets the data transmission tracking and reception requirements of the Meridian Phase II sounding rocket data mission, and realizes reliable communication of sounding rockets under limited station locations. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is the design process of the ground telemetry system of the sounding rocket;

[0026] Figure 2 It is the relationship between ground stations and ballistic surface layout (thermospheric sounding rocket);

[0027] Figure 3 It is the relationship between the ground station and the trajectory layout (ionospheric sounding rocket);

[0028] Figure 4 It is the vertical section pattern of the digital transmission antenna in the form of polar coordinate system;

[0029] Figure 5 It is the angle between the downlink of the Emen station during the ascent phase of the ionospheric sounding rocket and the direction of the rocket tail;

[0030] Figure 6 It is the angle between the downlink of the Emen station in the ascent phase of the thermospheric sounding rocket and the direction of the rocket's tail. DETAILED DESCRIPTION

[0031] The present invention proposes a design method for a sounding rocket ground telemetry system, comprising:

[0032] According to the link standard of the sounding rocket digital transmission data, combined with the ballistic simulation data of the sounding rocket, the communication link is simulated and calculated;

[0033] Determine the communication and tracking requirements based on the sounding rocket's trajectory simulation data, optional site data, and the launch and receiving characteristics of the rocket-borne antenna;

[0034] Determine the antenna specifications of the sounding rocket ground telemetry system and design the antenna layout plan based on communication and tracking requirements;

[0035] According to the antenna layout plan, the factors affecting the communication link quality of the sounding rocket ground telemetry system are simulated and analyzed to determine whether the sounding rocket ground telemetry system meets the sounding rocket mission requirements and complete the sounding rocket ground telemetry system.

[0036] The technical solution of the present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0037] Example

[0038] An embodiment of the present invention provides a design method for a ground telemetry system for a sounding rocket, which can provide a method reference for the design of a ground telemetry system for a sounding rocket.

[0039] This method is adopted, and this embodiment takes the two sounding rockets in the ionosphere and thermosphere of the Meridian Project Phase II as an example. First, according to the rocket trajectory simulation data and the optional station site, the sounding rocket data link communication and tracking requirements are calculated and analyzed as the basis for the ground antenna indicators; secondly, according to the demand analysis results, the ground station antenna type, tracking characteristics, layout method, effective range and other indicators are determined, and the ground telemetry system deployment plan is proposed; finally, according to the proposed ground telemetry system design plan, combined with the rocket trajectory simulation data, the link margin, rocket body shielding and other factors that affect the communication reliability are simulated and analyzed to examine whether the system design meets the mission requirements. The analysis results show that the design of the sounding rocket ground telemetry system proposed in this application meets the data transmission tracking and reception requirements of the Meridian Phase II sounding rocket data mission, and can achieve the full effective tracking and reception of the ground and space segments of the Meridian Phase II sounding rocket, and provide a method reference for the design of sounding rockets for other missions.

[0040] The system construction of a model mission generally includes the stages of mission demonstration, demand analysis, scheme design, test verification, and mission execution. This application takes the Meridian Project Phase II sounding rocket mission as an example, focusing on the needs of ground telemetry system construction in the sounding rocket mission, focusing on the needs analysis, scheme design, and simulation verification stages, converting the ground telemetry system design requirements into the basis for system indicator design, and proposing the key points of simulation verification. Summarize the general design process of the ground telemetry system for sounding rockets as follows: Figure 1As shown. In the demand analysis stage, the focus is on factors such as rocket trajectory, launch and reception characteristics of the onboard antenna, link data format and rate, and optional site, and the communication and tracking requirements of the telemetry system are analyzed; in the scheme design stage, the communication and tracking requirements are used as inputs, as the basis for selecting the antenna indicators of the telemetry system and the antenna layout plan, and the telemetry system scheme design is carried out; finally, through simulation analysis, the factors that affect the quality of the communication link, such as the arrow-to-ground link margin, antenna concave area, rocket body shielding and attitude control, and weather, are analyzed to verify whether the functions and performance of the ground telemetry system meet the mission requirements of the sounding rocket.

[0041] The following takes the telemetry system of the Meridian Project Phase II sounding rocket as an example. Figure 1 The main work carried out in each stage is explained in detail.

[0042] Construction needs analysis

[0043] The construction of the Meridian Project is divided into two phases: Meridian Project Phase I and Meridian Project Phase II. The Meridian Project Phase II started construction in 2019. The Meridian Project Phase II covers two sounding rocket launch missions in the ionosphere and thermosphere. The two sounding rockets in the thermosphere and ionosphere respectively conduct scientific detection of atmospheric characteristics at altitudes of about 210km and 320km. The ground telemetry system is an important part of the Meridian Project Phase II sounding rocket project. It is used to perform telemetry data receiving tasks for the two sounding rocket detection missions: ① System docking test and rehearsal test tasks in the pre-launch phase; ② Tracking and receiving tasks in the rocket flight phase after launch. The ground telemetry system is located in Emen Town and the launch site in Hainan Province. Considering that the guidance time of the sounding rocket is short and it is difficult to achieve precise trajectory control due to the influence of aerodynamics, combined with the characteristics of the short flight time and high altitude of the sounding rocket in this mission, facing the requirements of real-time reception, processing and forwarding of downlink data of the sounding rocket, the technical requirements of the ground telemetry system are analyzed from the two aspects of rocket communication requirements and tracking requirements.

[0044] Communication requirements analysis

[0045] The data transmission of the sounding rocket of the Meridian Project Phase II adopts the CCSDS data link standard, and the communication link is simulated and calculated in combination with the ballistic simulation data of the sounding rocket. There are two locations for the construction of the ground telemetry system, namely Eman Town in Hainan Province and Fuke Launch Site in Hainan Province. Among them, Eman Town is located on the flank of the ballistic surface and in front of the launch point; the launch site can be deployed on the launch site flat, the roof of the building in the site, etc.

[0046] The simulation calculation of the communication link shows that the maximum link distances between the ionospheric sounding rocket and the Emen station and the launch site are approximately 361.6km and 359.7km respectively, and the maximum link distances between the thermospheric sounding rocket and the Emen station and the launch site are 215km and 212km respectively. The relationship between the ground station and the ballistic surface layout is as follows: Figure 2 and Figure 3 Combined with the characteristics of the rocket-borne transmitting antenna, the key parameters of the communication link are shown in Table 1.

[0047] Table 1 Downlink data transmission link characteristics and requirements

[0048]

[0049] Tracking requirements analysis

[0050] Through the simulation data of rocket trajectory, the changes of pitch angle and azimuth angle between ionospheric and thermospheric sounding rockets and ground stations can be analyzed, and based on this, specific index requirements for the dynamic angle tracking capability of ground stations are proposed. The analysis and summary of the requirements for the pitch and azimuth technical indicators of the ionospheric and thermospheric sounding rockets of the Meridian Project Phase II are shown in Table 2. The indicators in the table can be used as the basis for designing and inspecting the relevant indicators of the angle tracking dynamic capability of the launch site and Emen Station.

[0051] Azimuth velocity calculation formula: θ is the range of azimuth angle change within time t;

[0052] Azimuth acceleration calculation formula: Describes the rate of change of the azimuth velocity ω with time t;

[0053] Pitch angular velocity calculation formula: φ is the range of pitch angle variation within time t;

[0054] Pitch angular acceleration calculation formula: Describes the rate of change of the pitch angular velocity ρ with time t.

[0055] Table 2 Analysis of azimuth and elevation requirements of ionospheric and thermospheric sounding rockets

[0056]

[0057] Ground telemetry system design

[0058] In order to achieve the purpose of full-link reception, a fixed antenna with self-tracking function was deployed in Eman Town, and the Eman station was used as the main receiving station during the flight phase. At the same time, considering the impact of distance, vegetation, terrain and other environments on the communication channel, several mobile stations were set up at the launch site, mainly for reception in the initial stage of flight, while ensuring the pre-launch test mission.

[0059] In addition, due to terrain obstruction and environmental factors, the Emen station cannot receive telemetry signals during the horizontal and vertical test phases of the rocket. The rocket needs to reach a certain height after launch to stably track the target. For the sake of safety, the Emen station considers 5° as the stable tracking benchmark. Through simulation calculations, when the ionospheric and thermospheric sounding rockets are launched for about 12.3s and 13.1s respectively, and the altitude is about 3.9km, the Emen station and the rocket can reach an elevation angle of 5°. By splicing the link arc data received by the launch site and the Emen station, the rocket telemetry data can be tracked and received throughout the process, while taking into account the pre-launch test tasks and the key arc reception guarantee during the flight. Combined with the above analysis results of the communication requirements and tracking requirements, the ground telemetry system design plan is shown in Table 3.

[0060] Table 3 Ground telemetry system design

[0061]

[0062] The ground telemetry system includes a total of 4 sets of ground receiving antennas. The launch site is equipped with 3 sets of receiving antennas: 1 set of low-gain wide-beam helical antenna, 1 set of medium-gain digital array antenna and 1 set of high-gain parabolic antenna. The low-gain wide-beam helical antenna is a mobile station, focusing on ensuring the pre-launch and rocket erection stage tests. At the same time, it has a low cost and is suitable for being placed close to the rocket launch point. Its directional pattern coverage performance ensures telemetry reception in the early stage of ignition; the medium-gain all-digital multi-beam broadband array antenna has a medium antenna gain and a relatively narrow directional pattern coverage. It has the advantages of fast tracking speed and strong dynamic adaptability. It focuses on ensuring telemetry reception in the early stage of flight. At the same time, as a mobile station, it also takes into account the pre-launch stage test tasks; the high-gain parabolic antenna has a large gain, which can ensure that the system has sufficient communication margin for long-distance reception. It serves as an external field station backup in the key action arc of the rocket to further ensure telemetry reception. The Emen station is equipped with a set of parabolic self-tracking fixed antennas and a single-pulse tracking system. It has the advantages of real-time and rapidity, as well as overhead tracking capabilities. As the main receiving station during the flight phase, it can achieve large-arc reception from the link pitch angle of about 5° to the rocket's landing in the sea.

[0063] Simulation Analysis

[0064] In order to examine the receiving and tracking capability of the ground telemetry system, the arrow-borne transmitting antenna pattern and trajectory simulation data are combined to analyze the effects of terrain shielding, digital antenna concave area, arrow tail shielding, and arrow body attitude changes. The integrity and reliability of the digital signal tracking and reception of the ground telemetry system are simulated and analyzed.

[0065] Link Margin Analysis

[0066] Combined with the launch system and channel characteristics, the receiving performance of each antenna of the ground telemetry system is analyzed. The EIRP of the launch system on the rocket is -8.5dBW, the data transmission rate is 4096bps, the modulation mode is BPSK, and the coding is RS (255, 223). Combined with the performance of the receiving antenna, the downlink data transmission link margin is calculated. The calculation results are shown in Table 4. The minimum value of the communication link margin is 3.3dB. The results show that each antenna can achieve stable reception. The performance of each antenna of the ground telemetry system has the basic conditions for achieving full-link reception through data splicing.

[0067] Table 4 Calculation of link margin of ground telemetry system

[0068]

[0069] Analysis of the impact of antenna concave area and rocket body shielding

[0070] During the rocket's ascent phase, if the ground station is in the antenna concave area, it will affect the ground station's receiving performance. At the same time, considering the shielding of the rocket body on the communication link, there is a null area of ​​the antenna pattern in the range of about ±5°. Considering that the launch site station only receives telemetry data in the early stage of flight, at this time the angle between the receiving antenna and the rocket body is large, the focus is on the possibility of the Emen station in the field being in the null area. The vertical section pattern of the digital transmission transmitting antenna is shown in Figure 2 According to the rocket trajectory data, the angle between the receiving link of the Emen station and the direction of the rocket tail is simulated and calculated. The simulation results are as follows: Figure 3 and Figure 4 shown.

[0071] Depend on Figure 3 , Figure 4 It can be found that during the flight of the two rockets in the ionosphere and thermosphere, the angle between the receiving link of the Emen station and the arrow tail direction was no less than 5°, and the ground station was not in the zero-sink area, which would not affect the receiving performance.

[0072] Rocket attitude control impact analysis

[0073] The tracking and receiving performance of the ground telemetry system is also affected by the attitude control factors of the sounding rocket. During the reentry phase of the Meridian Project Phase II sounding rocket, the rocket descended from 60km above the ground to 50km without attitude control. The rocket body attitude is expected to flip in the horizontal plane, which may cause the antenna null zone to align with the receiving antenna, which may cause the tracking target to be lost. At this time, in order to ensure that the ground station is not in the null zone of the launch antenna on the rocket, and considering that the rocket without control may shake, the distance between the ground station and the rocket projection point must be within the 70° inclination projection range of the rocket and the vertical ground direction. After calculation, the distance between the ground station and the rocket projection point in the rocket without control is shown in Table 5. The calculation results show that the Emen station is not in the null zone in the rocket without attitude control stage.

[0074] Table 5 Distance between the Emen station ground station and the rocket projection point in the non-attitude control stage of the ionospheric sounding rocket

[0075]

[0076] From the above analysis, it can be seen that according to the design plan and indicators of the ground telemetry system, combined with the characteristics of the onboard launch system, antenna radiation pattern, and rocket trajectory data, calculation and simulation analysis are carried out on the ground station receiving link margin, antenna null zone, and rocket attitude control during the flight phase of the sounding rocket. The results show that the ground telemetry system can track the target signal throughout the entire process and achieve reliable reception.

[0077] It should be noted that the method of the present invention is not limited to the ionospheric and thermospheric sounding rockets of the Meridian Project Phase II, and the above method can be used in various ground telemetry systems of sounding rockets.

[0078] Summarize:

[0079] In this embodiment, the Meridian Project Phase II ionospheric and thermospheric sounding rocket is used as an example to carry out calculation and analysis for the data link tracking and communication requirements of the sounding rocket, and a ground telemetry system design scheme is proposed using the method of the present invention. The simulation analysis results show that the sounding rocket ground telemetry system scheme design proposed based on this method meets the data transmission tracking and reception requirements of the Meridian Phase II sounding rocket data mission, and can provide a method reference for the design of sounding rocket schemes for other missions.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention is described in detail with reference to the embodiments, it should be understood by those skilled in the art that any modification or equivalent replacement of the technical solutions of the present invention does not depart from the spirit and scope of the technical solutions of the present invention and should be included in the scope of the claims of the present invention.

Claims

1. A design method for a sounding rocket ground telemetry system, comprising: According to the link standard of the sounding rocket digital transmission data, combined with the ballistic simulation data of the sounding rocket, the communication link is simulated and calculated; Determine the communication and tracking requirements based on the sounding rocket's trajectory simulation data, optional site data, and the launch and receiving characteristics of the rocket-borne antenna; Determine the antenna specifications of the sounding rocket ground telemetry system and design the antenna layout plan based on communication and tracking requirements; According to the antenna layout plan, the factors affecting the communication link quality of the sounding rocket ground telemetry system are simulated and analyzed to determine whether the sounding rocket ground telemetry system meets the sounding rocket mission requirements and complete the sounding rocket ground telemetry system.

2. The method for designing a sounding rocket ground telemetry system according to claim 1, characterized in that: The simulation calculation of the communication link includes: the maximum link distance between the sounding rocket and the launch site and the observation station respectively.

3. The method for designing a sounding rocket ground telemetry system according to claim 2, characterized in that: The communication requirements include: the maximum link distance of the optional launch site and / or observation station, the arrow-borne EIRP, the data transmission rate, the coding method and the modulation method.

4. The method for designing a sounding rocket ground telemetry system according to claim 2, characterized in that: The number of the observation stations is greater than or equal to one.

5. The method for designing a sounding rocket ground telemetry system according to claim 1, characterized in that: The tracking requirements include: the range of pitch angle φ and azimuth angle θ of the sounding rocket and the optional launch site and / or observation station in the ionosphere and thermosphere, azimuth velocity ω and acceleration α, pitch angle velocity ρ and acceleration β; wherein, Here, t represents the time.

6. The method for designing a sounding rocket ground telemetry system according to claim 1, characterized in that: The antenna indicators of the sounding rocket ground telemetry system include: meeting the signal tracking and reception of the sounding rocket from launch to landing in the sea, and the communication frequency band, maximum data rate, supported communication modulation mechanism and data reception bit error rate all meet the set requirements.

7. The method for designing a sounding rocket ground telemetry system according to claim 1, characterized in that: The antenna deployment plan includes: combining the influence of distance, vegetation and terrain on communication channels, and designing the antenna type, deployment location, deployment method, signal capture and tracking method and quantity for each optional site respectively, wherein the antenna types include: wide beam helical antenna, medium gain array antenna, high gain parabolic antenna and parabolic self-tracking antenna, the deployment location is a transmitting site or an observation station, the deployment method is mobile or fixed, and the signal capture and tracking methods include: initial locking, crossing capture and self-tracking.

8. The method for designing a sounding rocket ground telemetry system according to claim 1, characterized in that: The method of simulating and analyzing the factors affecting the quality of the communication link of the ground telemetry system of the sounding rocket according to the antenna layout scheme includes: According to the sounding rocket trajectory simulation data and the launch characteristics of the rocket-borne antenna, the signal strength at the ground station receiving antenna during the flight of the sounding rocket is calculated to obtain the link margin of the sounding rocket ground telemetry system. According to the characteristics of the antenna pattern on the rocket, it is determined whether the ground station is in the concave area of ​​the rocket antenna during the flight of the sounding rocket; According to the sounding rocket trajectory simulation data, determine whether the ground station's line of sight is blocked by the rocket body during the flight of the sounding rocket; According to the sounding rocket trajectory simulation data and the characteristics of the rocket-borne antenna pattern, the influence of the sounding rocket attitude change on the ground station tracking reception is analyzed; Wherein, the ground station includes a launch site and an observation station.

Images