Low earth orbit space situation awareness satellite optical payload parameter design evaluation platform

Abstract

This invention discloses a design and evaluation platform and method for optical payload parameters of low-Earth orbit space situational awareness satellites. The platform includes: an orbit modeling module, an attitude and solar orientation modeling module, a target and environment modeling module, an optical radiometry modeling module, an imaging and relative motion effect modeling module, a detection criterion and simulation scheduling module, a performance index evaluation module, and a result output module. These functional modules interact through a unified data interface, forming an integrated simulation evaluation platform. This invention integrates eight functional modules to construct a complete simulation chain. The unified data interface interaction solves the problem of fragmented models in traditional tools. The integrated modeling method tightly couples multiple physical processes, ensuring the physical consistency of the evaluation results, improving the credibility of the simulation results, and allowing direct use for engineering demonstration and scheme review. The platform has stronger autonomy and engineering portability, enhancing the physical consistency and engineering credibility of the evaluation results.

Description

Technical Field

[0001] This invention relates to the field of optical payload evaluation technology for low-Earth orbit space situational awareness (SSA) satellites, and particularly to a design and evaluation platform and method for optical payload parameters of low-Earth orbit space situational awareness satellites, applicable to the scheme demonstration, index evaluation and payload design stages of low-Earth orbit (LEO) satellite and space debris detection missions. Background Technology

[0002] With the rapid growth of low Earth orbit (LEO) satellite constellations, the number of effective spacecraft and debris in the 200–1,200 km orbital altitude range has increased significantly, especially in the 300–900 km altitude range, where target density is highly concentrated and the risk of space collisions has increased significantly. This places higher demands on space situational awareness systems for the continuous detection, identification, and cataloging of LEO targets.

[0003] In existing technologies, low-Earth orbit (LEO) target detection mainly relies on radar or ground-based optical systems. However, space-based optical payloads, due to their advantages such as wide coverage, fast response, and significant geometric advantages, are gradually becoming an important technological direction for LEO situational awareness. However, in engineering practice, the performance of optical payloads is affected by a combination of factors, including orbital parameters, attitude pointing, radiation conditions, target size, and relative motion, making it difficult to conduct a systematic evaluation using simple analytical formulas or single simulation tools.

[0004] Existing simulation evaluation methods typically suffer from the following shortcomings: First, simulation tools are highly dependent on external orbital mechanics or astronomical libraries, resulting in poor engineering portability; second, models for orbit, attitude, radiometrics, and imaging effects are fragmented, making it difficult to form a unified evaluation framework; third, there is a lack of an index system oriented towards the configuration of optical payload parameters, making it difficult to directly guide scheme design; and fourth, the output results are in a single form, making it difficult to directly support engineering demonstration, scheme comparison, and review delivery.

[0005] Therefore, it is necessary to propose a simulation and evaluation platform for optical payload parameters of low-Earth orbit space situational awareness satellites in sun-synchronous dawn-dusk orbits, so as to achieve a systematic, parameterized, and engineering-reliable evaluation of optical payload capabilities. Summary of the Invention

[0006] To address the aforementioned problems, the present invention aims to provide a design and evaluation platform and method for optical payload parameters of low-Earth orbit (LEO) space situational awareness satellites. This addresses the issues of poor engineering portability, fragmented models, and lack of an index system for configuring optical payload parameters in existing LEO space situational awareness satellite performance evaluations. The invention establishes a software evaluation platform and method for modeling, configuring parameters, and assessing the capabilities of optical payloads in Dawn-Dusk (SSO) orbits.

[0007] First aspect: A design and evaluation platform for optical payload parameters of low-Earth orbit space situational awareness satellites, including:

[0008] The orbit modeling module is used to establish a satellite motion model for a sun-synchronous dawn-dusk orbit, and to calculate the satellite's position vector in the inertial coordinate system at any given time by analyzing the motion model.

[0009] The attitude and solar orientation modeling module describes the pointing of the optical payload and is configured so that the optical axis always points in the direction of sunlight incidence.

[0010] The target and environment modeling module is used to describe the physical and orbital characteristics of the detected target and to determine whether the target and payload are in the Earth's shadow area.

[0011] The optical radiation metrology model module is used to calculate the effective photon signal of the target entering the optical payload under given observation conditions, and output the number of effective signal electrons in a single exposure.

[0012] The imaging and relative motion effect model module is used to describe the imaging characteristics of the target being detected on the focal plane;

[0013] The detection criteria and simulation scheduling module is used to sample multiple observation times within the orbital period and determine whether the detection was successful based on preset detection criteria.

[0014] Performance evaluation module; used to statistically analyze the results of multiple simulations to form a capability index system for optical payloads;

[0015] The results output module is used to export simulation evaluation results as structured data files;

[0016] The various functional modules interact through a unified data interface to form an integrated simulation and evaluation platform.

[0017] In one embodiment of the present invention, the

[0018] In the satellite motion model, the satellite undergoes analytical circular orbit motion in the geocentric inertial coordinate system. The satellite orbital altitude is configurable by the user, and the satellite orbital inclination is set to meet the sun synchronization condition.

[0019] In one embodiment of the present invention, the physical and orbital characteristics of the detected target include: target diameter, target albedo, and target orbital height.

[0020] In one embodiment of the present invention, the optical radiation metrology model module calculates the effective photon signal of the detected target entering the optical payload under given observation conditions, including:

[0021] Calculation of the effective scattering cross section of the target, solar irradiance model, optical system aperture and transmittance and quantum efficiency model, and detection exposure time model.

[0022] In one embodiment of the present invention, the imaging and relative motion effect model module includes: a pixel angular resolution model, a target relative angular velocity model, and an imaging trail length model.

[0023] In one embodiment of the present invention, the sampling of each observation time by the detection criterion and simulation scheduling module includes:

[0024] Calculate the relative geometric relationship between the satellite and the target, determine the lighting and ground shadow conditions, calculate the optical signal and signal-to-noise ratio, and calculate the imaging trailing.

[0025] In one embodiment of the present invention, the capability index system includes:

[0026] Trends in detection probability, minimum detectable target size, and detection capability at different orbital altitudes.

[0027] The second aspect: A method for designing and evaluating the optical payload parameters of a low-Earth orbit space situational awareness satellite, including the following steps:

[0028] S1. Start the evaluation platform and initialize the configuration parameters;

[0029] S2. Set the track, load, and target size information, and sample the track period according to the time step;

[0030] S3. Calculate the satellite position, solar direction, and payload orientation at the current moment to generate target parameters;

[0031] S4. Based on the target parameters, if it is determined that the target is in the Earth's shadow area, the detection results are recorded directly.

[0032] S5. If the target is determined to be outside the Earth's shadow area, calculate the laser signal, relative velocity, trailing image, and signal-to-noise ratio (SNR).

[0033] S6. If SNR ≥ threshold and ghosting ≤ threshold, mark as successful detection; otherwise, mark as undetected.

[0034] S7. Record the detection results, and repeat S3-S6 to detect at the next moment.

[0035] S8. Statistical analysis of the detection results, calculation of performance indicators, generation of output files, and termination of the detection.

[0036] Third aspect: An electronic device including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the program, performs the steps of the method provided in the second aspect.

[0037] Fourth aspect: A non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method provided in the second aspect.

[0038] The beneficial effects of this invention are:

[0039] 1. This invention constructs a complete simulation chain by integrating eight functional modules: orbit modeling, attitude and solar orientation modeling, target and environment modeling, optical radiometry, imaging and relative motion effects, detection criteria and simulation scheduling, performance index evaluation, and result output. Each module is implemented using analytical models and interacts through a unified data interface, effectively solving the problem of fragmented models in traditional tools. This integrated modeling method tightly couples multiple physical processes such as orbital mechanics, radiative transfer, and imaging effects, ensuring the physical consistency of the evaluation results and significantly improving the credibility of the simulation results, enabling them to be directly used for engineering demonstration and scheme review. Compared with traditional methods that rely on external astronomical libraries or single simulation tools, this platform has stronger autonomy and engineering portability, achieving unified modeling of multiple physical effects and improving the physical consistency and engineering credibility of the evaluation results.

[0040] 2. This invention's platform can output key performance indicators such as detection probability, minimum detectable target size, and detection capability variation trends at different orbital altitudes, forming a quantifiable and comparable evaluation system. For example, through orbital altitude scanning analysis and target size sensitivity analysis, the platform can clearly reveal the quantitative relationship between optical payload parameters (such as aperture and focal length) and detection capability. This structured output overcomes the shortcomings of traditional evaluation methods, which produce results in a single format and are difficult to directly guide design. It provides direct and reliable data support for payload parameter selection and system scheme optimization, effectively accelerating the scheme demonstration process and forming a quantitative and reproducible optical payload performance indicator system, directly supporting engineering design decisions.

[0041] 3. This invention's platform is specifically designed for sun-synchronous twilight orbits. Its attitude modeling module pre-sets the optical payload's optical axis to always point towards the direction of sunlight incidence, fully utilizing the unique continuous illumination conditions of this orbit. This configuration greatly improves the visibility of low-Earth orbit targets, making it particularly suitable for detecting high-density debris zones in the 700–900 km altitude range. Through detailed modeling of key effects such as imaging trailing and shadow zone criteria, the platform can accurately simulate detection scenarios under sun-aligned conditions. The evaluation results are closer to actual mission requirements, providing a highly targeted simulation evaluation capability for optical payload configuration in low-Earth orbit situational awareness missions. Targeted optimization of twilight orbit detection scenarios significantly improves the accuracy of low-Earth orbit target detection performance evaluation. Attached Figure Description

[0042] Figure 1This is a schematic diagram of the optical load parameter simulation and evaluation platform of the present invention;

[0043] Figure 2 This is a flowchart illustrating the optical load parameter simulation and evaluation method of the present invention;

[0044] Figure 3 This is a graph showing the probability assessment results of orbital height scanning in this invention;

[0045] Figure 4 This is a graph showing the probability assessment results of the minimum detectable size of the present invention;

[0046] Figure 5 The screenshot shows the parameter settings and evaluation results of the evaluation platform of this invention.

[0047] Figure 6 The screenshot shows the parameter settings and evaluation results of the evaluation platform of this invention.

[0048] Figure 7 This is a schematic diagram of the structure of the electronic device of the present invention. Detailed Implementation

[0049] Embodiments of the present invention are described in detail below. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar symbols denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0050] This invention discloses a design and evaluation platform and method for optical payload parameters of low-Earth orbit space situational awareness satellites. To make the purpose, technical solution and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments.

[0051] Example 1:

[0052] This embodiment discloses a design and evaluation platform for optical payload parameters of a low-Earth orbit space situational awareness satellite, such as... Figure 1 As shown, the evaluation platform includes: orbit modeling module, attitude and solar direction modeling module, target and environment modeling module, optical radiometric modeling module, imaging and relative motion effect modeling module, detection criterion and simulation scheduling module, performance index evaluation module, and result output module. All functional modules interact through a unified data interface to form an integrated simulation evaluation platform.

[0053] Among them, the orbit modeling module is used to establish a satellite motion model of a sun-synchronous dawn-dusk orbit, and to achieve high-precision orbit simulation based on the principles of orbital mechanics.

[0054] The satellite's position vector in the inertial coordinate system at any given time is calculated by analyzing the satellite motion model. The satellite orbit is a near-circular orbit, which balances practicality and computational efficiency. The specific configuration supports flexible customization.

[0055] By analyzing the satellite motion model, the orbital altitude can be configured by the user, allowing them to freely set the altitude according to mission requirements and adapt to different low-Earth orbit detection scenarios. The orbital inclination is set to meet the sun synchronization condition, ensuring that the angle between the satellite's orbital plane and the ecliptic plane remains constant, achieving stable observations during dawn and dusk. The satellite performs near-circular orbital motion in an analytically formed orbital system within the geocentric inertial coordinate system.

[0056] The module employs an analytical satellite motion model to accurately analyze the satellite orbit in a geocentric inertial coordinate system. It can quickly calculate the satellite's position vector and velocity parameters at any given time, providing fundamental data support for subsequent calculations of the relative geometric relationship between the satellite and the target, and determination of detection conditions, thus ensuring the geometric accuracy of the entire simulation process.

[0057] The attitude and solar orientation modeling module describes the pointing of the optical payload and is configured so that the optical axis always points in the direction of sunlight incidence.

[0058] The sun's direction is approximately fixed in inertial space. This attitude configuration satisfies the continuous illumination detection scenario under dawn / dusk orbit conditions, which is beneficial for improving the illumination visibility of low-Earth orbit targets.

[0059] The attitude and solar orientation modeling module focuses on the accurate modeling of satellite attitude and solar orientation, providing a stable pointing reference and illumination support for optical payload detection. The optical payload's attitude configuration adopts an optical axis tracking design, meaning that the payload's optical axis always points in real time towards the direction of sunlight incidence. This configuration works in conjunction with the sun-synchronous twilight orbit to maximize the use of natural light resources, ensuring that the target area receives continuous and stable illumination during the typical observation period of the twilight orbit. This significantly improves the visibility of low-Earth orbit targets and reduces the impact of insufficient illumination on detection performance.

[0060] In terms of solar orientation modeling, considering that the distance between the sun and the satellite is much greater than the satellite orbit scale, the solar orientation is approximated as a fixed direction in inertial space. By pre-setting the solar azimuth vector parameters, the modeling accuracy is ensured while simplifying the calculation, providing a reliable solar orientation input for subsequent modules such as optical radiation measurement and illumination condition determination.

[0061] The target and environment modeling module, which includes two sub-modules, the target modeling module and the environment modeling module, is used to describe the physical and orbital characteristics of the target being detected and to determine whether the target and payload are in the shadow area. It comprehensively covers the simulation requirements of the characteristics of the detected object and the external environmental conditions, and provides complete scene input for the simulation of the detection process.

[0062] The target modeling submodule focuses on the core physical and orbital characteristics of the target being detected, supporting fine-grained simulation configuration of key parameters: it allows for customizable target diameters to accommodate targets of varying sizes, from small space debris to large satellites; it supports setting target albedo parameters to simulate the differences in solar radiation reflection capabilities of targets made of different materials; and it allows for configuring target orbital altitudes to recreate the target motion characteristics at different low Earth orbit altitudes, achieving accurate reproduction of diverse target scenarios. It enables modeling and simulation of target diameter, target albedo, and target orbital altitude.

[0063] The environmental modeling submodule is primarily responsible for determining lighting conditions. Its core function is to determine whether the satellite payload and target are within the Earth's shadow. The module employs a mature cylindrical shadow model from engineering applications, treating sunlight as parallel light. By calculating the spatial geometric relationship between the Sun, Earth, and satellite, it accurately determines whether the target and payload are obscured by the Earth, thereby determining the effective lighting conditions at the current observation time. This provides crucial environmental data for subsequent optical signal calculations and feasibility assessments.

[0064] The optical radiation metrology model module is used to calculate the effective photon signal of the target entering the optical payload under given observation conditions, and outputs the number of effective signal electrons in a single exposure.

[0065] The optical radiation metrology model module is the core module for realizing the quantization of optical detection signals. Through multi-physics process modeling, it accurately calculates the number of effective signal electrons entering the optical payload in a single exposure.

[0066] The core modeling process of the optical radiometric model module covers four key steps: First, the effective scattering cross section of the target is calculated, and the target's ability to scatter solar radiation is determined by combining the target's size, shape, and albedo parameters; second, a solar irradiance model is constructed, incorporating the solar constant and atmospheric attenuation correction factor to accurately describe the intensity of solar radiation reaching the target surface; third, an optical system characteristic model is established, comprehensively considering core parameters such as the optical system aperture, transmittance, and detector quantum efficiency to quantify the transmission and conversion efficiency of the optical system for radiation signals; finally, combined with the detector exposure time model, the total number of photons received by the detector within a set exposure time is calculated and converted into the effective signal electron count output.

[0067] The entire modeling process strictly follows the laws of optical radiation transmission to ensure the accuracy of signal calculations and provide a reliable data foundation for subsequent signal-to-noise ratio analysis.

[0068] The Imaging and Relative Motion Effects Model Module is used to describe the imaging characteristics of the target being detected on the focal plane.

[0069] The imaging and relative motion effect model module includes: a pixel angular resolution model, a target relative angular velocity model, and an imaging trail length model. By modeling the trail effect, the impact of target relative motion on the signal-to-noise ratio and detection criteria is incorporated into the simulation process.

[0070] The imaging and relative motion effect model module focuses on simulating the imaging characteristics of the target on the load focal plane, emphasizing the image quality features and the detection effects caused by relative motion.

[0071] The imaging and relative motion effect model module comprises three core models: a pixel angular resolution model, which calculates the spatial resolution capability of the payload and determines the smallest resolvable target detail by combining parameters such as the focal length of the optical system and the pixel size of the detector; a target relative angular velocity model, which calculates the relative angular velocity of the satellite and the target in inertial space in real time based on their orbital parameters, reflecting the target's motion characteristics in the field of view; and an imaging trail length model, which calculates the trail length formed by the target on the focal plane based on the relative angular velocity and exposure time, while also incorporating a Gaussian point spread model to simulate the energy distribution characteristics of the trail. Through refined modeling of these imaging effects, the impact of target relative motion on imaging quality, signal-to-noise ratio, and detection criteria is comprehensively incorporated into the simulation process, making the simulation results more closely resemble actual detection scenarios.

[0072] The detection criteria and simulation scheduling module is used to sample multiple observation times within the orbital period and determine whether the detection was successful based on preset detection criteria.

[0073] The steps performed at each observation time include: calculating the relative geometric relationship between the satellite and the target; determining the illumination and shadow conditions; calculating the optical signal and signal-to-noise ratio; calculating the imaging trail; and determining whether the detection was successful based on preset detection criteria, including a signal-to-noise ratio threshold and a trail length threshold.

[0074] The detection criteria and simulation scheduling module is responsible for the scheduling and control of the simulation process and the judgment of detection results, realizing automated simulation and judgment throughout the entire orbital period. In terms of simulation scheduling, the module supports flexible sampling of observation times within the satellite's orbital period, and the sampling interval can be adjusted according to the simulation accuracy requirements, ensuring detailed coverage of detection during critical periods while maintaining simulation efficiency. Regarding the execution of detection criteria, five core steps are completed sequentially for each sampling time: calculating the relative geometric relationship between the satellite and the target based on orbit and target parameters to determine the detection angle and distance; calling the results from the environmental modeling module to judge the current lighting and shadow conditions and select effective detection time periods; calculating the signal-to-noise ratio (SNR) using the signal electron count output from the optical radiometry model combined with system noise parameters; obtaining the trailing shadow length through the imaging and relative motion effect model; and finally, based on preset dual-threshold criteria—the SNR threshold and the trailing shadow length threshold—a comprehensive judgment is made on whether the target was successfully detected at that moment, forming the judgment result for a single observation.

[0075] The performance evaluation module is used to perform statistical analysis on the results of multiple simulations to form a capability index system for optical payloads.

[0076] The capability index system includes, but is not limited to: detection probability; minimum detectable target size; and the trend of detection capability variation at different orbital altitudes. This index system can be directly used for comparative evaluation between different payload parameters and orbital schemes.

[0077] The performance evaluation module constructs a comprehensive optical payload capability index system through statistical analysis of multiple simulation results, providing a quantitative basis for scheme evaluation.

[0078] The indicator system is designed around the core requirements of detection performance and mainly includes: detection probability, which statistically analyzes the percentage of successful target detections under a given scenario, reflecting the overall detection reliability of the payload; minimum detectable target size, which determines the smallest target diameter that the payload can identify under a given detection probability by traversing simulations of targets of different sizes; and the trend of detection capability changes at different orbital altitudes, analyzing the changing patterns of indicators such as detection probability and minimum detectable target size under different satellite orbital altitude configurations. In addition, auxiliary indicators such as detection performance under different lighting conditions and the impact of system noise on detection can be added. This indicator system supports multi-dimensional comparative analysis and can be directly used to determine the performance advantages and disadvantages between different combinations of optical payload parameters and different orbital schemes, providing clear optimization directions for engineering design.

[0079] The results output module is used to export simulation evaluation results into structured data files for subsequent analysis, archiving, and engineering verification.

[0080] The results output module is responsible for standardizing and outputting intermediate data and final evaluation results during the simulation process, meeting the needs of subsequent analysis, archiving, and engineering verification. The output includes structured data files and visualized results reports. The structured data files cover all data, including satellite orbital parameters, target characteristic parameters, signal electron count at each time point, signal-to-noise ratio, trailing length, detection judgment results, and performance index statistics. These are stored in a common data format for easy secondary analysis and data sharing. The visualized reports present the simulation results intuitively through charts and graphs, including detection probability curves, comparison charts of minimum detectable target sizes, and trend charts of detection performance changes under different conditions, making the evaluation results easier to understand and apply. The output results ensure both data completeness and accuracy while also considering practicality and readability, providing strong support for engineering decision-making.

[0081] The various functional modules interact through a unified data interface to form an integrated simulation and evaluation platform.

[0082] This assessment platform is used as follows: Figure 5and Figure 6 As shown in the figure, the left side of the figure shows the user parameter settings, and the right side shows the evaluation result data visualization. The parameter settings on the left mainly include satellite orbit parameter design, optical payload parameter design, space target simulation parameters, etc. The evaluation results include the distribution curve of space target detectability probability with orbital altitude, the distribution curve of space target detectability probability with target diameter, the distribution curve of space target coverage with orbital altitude, etc.

[0083] Based on the modular architecture of the evaluation platform in this embodiment, the challenges of complex evaluation processes, high coupling, and poor engineering applicability of optical payloads for low-Earth orbit (LEO) space situational awareness satellites are resolved. A simulation model of the LEO satellite optical payload suitable for sun-synchronous twilight orbits is constructed; the detection capabilities of space situational awareness satellites under different orbital parameter conditions are evaluated using orbital altitude as the primary variable; modeling of detection scenarios for the optical payload under sunlight-directed pointing conditions is achieved; simulation of detection of LEO satellites and debris targets with diameters ≥1 cm to >1 m is supported; a quantifiable and comparable optical payload performance index system is constructed; and data and results that can be directly applied to engineering demonstrations and scheme reviews are output.

[0084] Example 2:

[0085] Based on the evaluation platform structure of Embodiment 1, this embodiment discloses a method for designing and evaluating the optical payload parameters of a low-Earth orbit space situational awareness satellite, such as... Figure 2 As shown, the steps include:

[0086] S1. Start the evaluation platform and initialize the configuration parameters.

[0087] The simulation and evaluation platform for optical payload parameters of the low-Earth orbit space situational awareness satellite is launched, and the platform's preset basic algorithm model and data interface protocol are loaded. Core configuration parameters are initialized, including general environmental parameters such as inertial coordinate system, Earth's average radius, and solar constant; system operating parameters such as simulation calculation accuracy threshold, data storage path, and log recording switch are set; default parameter configurations for each functional module are initialized, and the data interaction channels between modules are established to ensure the platform enters a ready state.

[0088] S2. Set the track, load, and target size information, and sample the track period according to the time step.

[0089] Orbit parameter settings: Input the satellite orbit type (e.g., sun-synchronous dawn-dusk near-circular orbit), configure the user-defined orbit altitude, and the system will automatically calculate the orbit inclination that meets the sun-synchronous conditions; it supports importing satellite two-line report files to improve orbit simulation accuracy and reduce orbit drift error.

[0090] Load parameter settings: Enter the core parameters of the optical load, including optical system aperture, transmittance, quantum efficiency, focal length, detector pixel size, exposure time, etc., to clarify the basic boundaries of load performance.

[0091] Target size setting: Define the diameter parameter of the target to be detected. Multiple target samples of different sizes can be configured at the same time to adapt to diverse detection scenario requirements.

[0092] Orbital period sampling: Set the time step within the orbital period, and generate the observation time sequence within the entire orbital period according to the uniform sampling rule to ensure coverage of key observation periods.

[0093] S3. Calculate the satellite position, sun direction, and payload orientation at the current moment to generate target parameters.

[0094] Satellite position calculation: Based on the analytical motion model of the orbit modeling module, combined with the current sampling time, the precise position vector and velocity parameters of the satellite in the geocentric inertial coordinate system are calculated.

[0095] Calculation of solar direction and load orientation: The solar direction is approximated as a fixed direction in inertial space, and the solar incident direction vector is output; the precise pointing angle of the load at the current moment is calculated according to the attitude configuration that the load optical axis always points to the incident sunlight.

[0096] Target parameter generation: Outputs the target's core parameters such as orbital altitude, diameter, and albedo, and simultaneously calculates the target's position vector in the geocentric inertial coordinate system, providing data support for subsequent geometric relationship analysis.

[0097] S4. Based on the target parameters, if the target is determined to be in the Earth's shadow area, the detection results are recorded directly.

[0098] A cylindrical shadow model of the Earth combined with vector calculation methods is used to determine whether a target is located in the Earth's shadow region. This is achieved by calculating the dot product (Ci) of the target's position vector in the geocentric inertial coordinate system and the solar direction vector. OD ), and the vertical distance from the target to the sunlight (C DM ), compared to the Earth's radius (R) e Determine target visibility: If C OD ≤0 or C DM ≥R e The target is not in the shadow area; if C OD >0 and C DM <R e The target is located in the shadow area.

[0099] If the area is determined to be a shadow area, the detection result at that moment is recorded as not detected, and key data such as the target location and the basis for the shadow determination are stored.

[0100] S5. If the target is determined to be outside the Earth's shadow area, calculate the laser signal, relative velocity, trailing image, and signal-to-noise ratio (SNR).

[0101] Laser signal calculation, combined with the target's effective scattering cross section, solar irradiance, optical system transmittance, and quantum efficiency, calculates the number of effective signal electrons entering the payload in a single exposure.

[0102] Relative velocity calculation, based on the position vectors and velocity parameters of the satellite and the target, solves for the relative angular velocity and linear velocity of the two in inertial space.

[0103] Motion blur calculation calculates the length of the target's shadow on the focal plane based on relative angular velocity and exposure time, combined with pixel angular resolution, to simulate the imaging blur effect caused by motion.

[0104] The signal-to-noise ratio (SNR) is calculated based on the effective signal electron count and system noise (including dark current noise, readout noise, etc.) parameters. The SNR value at the current observation time is calculated using the ratio formula of signal and noise.

[0105] S6. If SNR ≥ threshold and ghosting ≤ threshold, mark as successful detection; otherwise, mark as undetected.

[0106] The system invokes preset detection criterion thresholds. The SNR threshold and the trailing length threshold can be adjusted by the user according to task requirements for a comprehensive dual-condition judgment.

[0107] If the calculated SNR is greater than or equal to the threshold and the trailing shadow is less than or equal to the threshold, the target is considered to have been successfully detected at that moment, and the result is marked as successfully detected; if either condition is not met, the result is marked as not detected, and the specific threshold indicators and calculation data that are not met are recorded.

[0108] S7. Record the detection results, and repeat S3-S6 to detect at the next moment.

[0109] The current detection results, satellite and target position parameters, SNR values, trail length, and ground shadow determination results are stored in the database in a structured format.

[0110] The evaluation platform automatically switches to the next sampling time and repeats the process of S3 parameter calculation - S4 ground shadow determination - S5 physical quantity calculation - S6 detection determination until the detection simulation of all sampling times within the orbital period is completed.

[0111] S8. Statistical analysis of the detection results, calculation of performance indicators, generation of output files, and termination of the detection.

[0112] Results statistics: The detection results of all sampling times within the orbital period are summarized, and the number of successful detections, the number of undetected detections, and the corresponding time distribution are statistically analyzed.

[0113] Performance metrics calculation: Generate core performance metrics, including detection probability (number of successful detections / total number of samples), minimum detectable target size (calculated by back-calculating the detection probability of targets of different sizes), and the trend of detection capability changes at different orbital altitudes.

[0114] Output file generation: Export statistical data, performance indicators, and raw calculation data at each time point into structured files (supporting formats such as CSV and Excel), and simultaneously generate a visualization report (including detection probability curves, trailing shadows, and SNR distribution charts) for subsequent analysis, archiving, and engineering demonstration. After the simulation is completed, the platform running process is closed.

[0115] Application Example 1: Detection Probability (Pd) of space targets at different orbital altitudes under a set of optical payload parameter settings.

[0116] With a fixed set of satellite orbit and optical payload parameters, the probability analysis of the payload detecting space targets within the orbital altitude range of 600km to 1200km is calculated. The optical payload model parameters are set as follows:

[0117] {

[0118] "mode": "scan_altitude", / / Evaluation mode is high-altitude patrol

[0119] "satellite altitude_km": 800 km

[0120] "sensor": { / / Optical payload sensor

[0121] "aperture_m": 0.6, / / Aperture of the optical system in meters

[0122] "focal_length_m": 1.5, / / focal length m

[0123] "pixel_size_um": 10, / / pixel size

[0124] "resolution": 4096, / / Image size

[0125] "qe": 0.9, / / Detector quantum efficiency

[0126] "dark_current_e": 0.1, / / Dark current noise parameter

[0127] "read_noise_e": 1.0, / / Read noise

[0128] "exposure_time_s": 0.001, / / exposure time

[0129] "throughput": 0.8 / / Transmittance of the optical system

[0130] },

[0131] "target": {

[0132] "diameter_m": 0.2, / / Minimum diameter of the space target in m

[0133] "albedo": 0.5, target albedo

[0134] },

[0135] "orbit_altitudes_km": [600, 700, 800, 900, 1000] Patrol altitude range

[0136] }

[0137] The evaluation results output by the platform are as follows Figure 3 As shown:

[0138] The figure shows that the X-axis represents the altitude variation of different space targets, and the Y-axis represents the altitude of the payload. Under the set model parameters, the probability that a space target can be detected and identified is shown. The results show that the satellite has a 65% probability of detecting targets at altitudes of 800-1000 km when it is at an altitude of 800 km. Further optimization of parameter settings is needed.

[0139] Application Example 2: Calculate and evaluate the impact of optical payload parameters on the diameter and detection probability Pd of different space targets.

[0140] Taking a sun-synchronous dawn-dusk orbit at an altitude of 800 km as an example, with an optical payload aperture of 25 cm and a focal length of 1.5 m, simulation evaluation was conducted on low-Earth orbit debris with a target diameter ranging from 1 cm to 10 cm. Through detection simulations at multiple moments within the orbital period, detection probability curves for different target sizes were statistically obtained, thereby determining the minimum stable target size that the system can detect.

[0141] Platform model parameter settings:

[0142] {

[0143] "mode": "min_detectable",

[0144] "sensor": {

[0145] "aperture_m": 0.25, / / Aperture of the optical system in meters

[0146] "focal_length_m": 1.5, / / focal length m

[0147] "pixel_size_um": 10, / / resolution

[0148] "resolution": 4096, / / Image size

[0149] "qe": 0.7, / / Detector quantum efficiency

[0150] "read_noise_e": 5.0, / / Read noise

[0151] "dark_current_e": 0.1, / / Dark current noise parameter

[0152] "exposure_time_s": 0.5 / / Exposure time

[0153] },

[0154] "target": {

[0155] "diameter_m": 0.05, / / Minimum target diameter

[0156] "albedo": 0.3, / / Target reflectivity

[0157] "altitude_km": 800 / / Target altitude

[0158] },

[0159] }

[0160] The output result is as follows Figure 4 As shown:

[0161] In the figure, the X-axis represents the orbital altitude of 800km and the diameter variation of different space targets. The Y-axis represents the detection probability Pd of targets with different diameters that can be observed by the optical payload under the given parameter settings.

[0162] Application Example 3: Evaluate coverage of space targets based on the combination of main optical payload settings.

[0163] Target detection coverage in the main debris belt at orbital altitudes of 700–900 km under different combinations of key optical payload parameters, including optical lens aperture, focal length, and minimum detection diameter.

[0164] The platform model parameters are set as follows:

[0165] {

[0166] "mode": "coverage_700_900" / / Evaluation mode

[0167] "sensor": {

[0168] "aperture_m": 0.25~60, / / Optical aperture

[0169] "focal_length_m": 1.0~2.0, / / focal length

[0170] "pixel_size_mm": 10, / / resolution

[0171] "resolution": 4096, / / Image size

[0172] "qe": 0.7, / / Detector quantum efficiency

[0173] "read_noise_e": 5.0, / / Read noise

[0174] "dark_current_e": 0.1, / / Dark current noise parameter

[0175] "exposure_time_s": 0.5 / / Exposure time

[0176] },

[0177] "orbit_altitude_km": 800, / / orbit altitude

[0178] "diameter_m": 0.05 / / Minimum target diameter

[0179] }

[0180] Output: Weighted Coverage 700–900 km: 0.78

[0181] Parameter selection recommendation table (aperture / focal length scanning)

[0182] {

[0183] "mode": "parameter_table" / / Evaluation method

[0184] "apertures_m": [0.2, 0.25, 0.3], / / Optical aperture

[0185] "focal_lengths_m": [1.2, 1.5, 2.0], / / Focal length

[0186] "orbit_altitude_km": 800, / / orbit altitude

[0187] "target_altitude_km": 800, / / Target altitude

[0188] "diameters_m": [0.02, 0.03, 0.05, 0.08] / / Target diameter range

[0189] }

[0190] The evaluation results are shown in Table 1:

[0191] Table 1 Evaluation Results

[0192] aperture_cm lens diameter focal_length_m focal length min_detectable_cm minimum distance coverage_700_900 target coverage 25.0 1.0 0.05 0.6333333333333333 25.0 1.5 0.05 0.6333333333333333 25.0 2.0 0.05 0.6333333333333333 35.0 1.0 0.05 0.6333333333333333 35.0 1.5 0.05 0.6333333333333333 35.0 2.0 0.05 0.6333333333333333 50.0 1.0 0.05 0.6333333333333333 50.0 1.5 0.05 0.6333333333333333 50.0 2.0 0.05 0.6333333333333333 60.0 1.0 0.05 0.6346231974848379 60.0 1.5 0.05 0.6346231974848379 60.0 2.0 0.05 0.6346231974848379

[0193] Performance evaluation: Under the current simulation configuration, the coverage rate is consistently 63.33% when the aperture is ≤50cm, and only slightly increases to 63.46% when the aperture increases to 60cm; the focal length has no effect on the coverage rate in the range of 1.0–2.0m (possibly limited by other fixed parameters or criterion thresholds).

[0194] The present invention also provides an electronic device, Figure 7 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention, such as... Figure 7 As shown, the electronic device may include a processor, a communications interface, memory, and a communication bus, wherein the processor, communications interface, and memory communicate with each other via the communication bus. The processor can invoke logical instructions from the memory, for example, to execute the following method:

[0195] S1. Start the evaluation platform and initialize the configuration parameters;

[0196] S2. Set the track, load, and target size information, and sample the track period according to the time step;

[0197] S3. Calculate the satellite position, solar direction, and payload orientation at the current moment to generate target parameters;

[0198] S4. Based on the target parameters, if it is determined that the target is in the Earth's shadow area, the detection results are recorded directly.

[0199] S5. If the target is determined to be outside the Earth's shadow area, calculate the laser signal, relative velocity, trailing image, and signal-to-noise ratio (SNR).

[0200] S6. If SNR ≥ threshold and ghosting ≤ threshold, mark as successful detection; otherwise, mark as undetected.

[0201] S7. Record the detection results, and repeat S3-S6 to detect at the next moment.

[0202] S8. Statistical analysis of the detection results, calculation of performance indicators, generation of output files, and termination of the detection.

[0203] Furthermore, the logical instructions in the aforementioned memory can be implemented as software functional units and sold or used as independent products, and can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0204] This invention also provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, is implemented to perform the methods provided in the above embodiments, including, for example:

[0205] S1. Start the evaluation platform and initialize the configuration parameters;

[0206] S2. Set the track, load, and target size information, and sample the track period according to the time step;

[0207] S3. Calculate the satellite position, solar direction, and payload orientation at the current moment to generate target parameters;

[0208] S4. Based on the target parameters, if it is determined that the target is in the Earth's shadow area, the detection results are recorded directly.

[0209] S5. If the target is determined to be outside the Earth's shadow area, calculate the laser signal, relative velocity, trailing image, and signal-to-noise ratio (SNR).

[0210] S6. If SNR ≥ threshold and ghosting ≤ threshold, mark as successful detection; otherwise, mark as undetected.

[0211] S7. Record the detection results, and repeat S3-S6 to detect at the next moment.

[0212] S8. Statistical analysis of the detection results, calculation of performance indicators, generation of output files, and termination of the detection.

[0213] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0214] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0215] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A design and evaluation platform for optical payload parameters of a low-Earth orbit space situational awareness satellite, characterized in that, include: The orbit modeling module is used to establish a satellite motion model for a sun-synchronous dawn-dusk orbit, and to calculate the satellite's position vector in the inertial coordinate system at any given time by analyzing the motion model. The attitude and solar orientation modeling module describes the pointing of the optical payload and is configured so that the optical axis always points in the direction of sunlight incidence. The target and environment modeling module is used to describe the physical and orbital characteristics of the detected target and to determine whether the target and payload are in the Earth's shadow area. The optical radiation metrology model module is used to calculate the effective photon signal of the target entering the optical payload under given observation conditions, and output the number of effective signal electrons in a single exposure. The imaging and relative motion effect model module is used to describe the imaging characteristics of the target being detected on the focal plane; The detection criteria and simulation scheduling module is used to sample multiple observation times within the orbital period and determine whether the detection was successful based on preset detection criteria. Performance evaluation module; This is used to statistically analyze the results of multiple simulations and form a capability index system for optical payloads; The results output module is used to export simulation evaluation results as structured data files; The various functional modules interact through a unified data interface to form an integrated simulation and evaluation platform.

2. The evaluation platform of claim 1, wherein, In the satellite motion model, the satellite undergoes analytical circular orbit motion in the geocentric inertial coordinate system. The satellite orbital altitude is configurable by the user, and the satellite orbital inclination is set to meet the sun synchronization condition.

3. The evaluation platform of claim 1, wherein, The physical and orbital characteristics of the target being detected include: target diameter, target albedo, and target orbital altitude.

4. The evaluation platform of claim 1, wherein, The optical radiometric model module calculates the effective photon signal of the target entering the optical payload under given observation conditions, including: Calculation of the effective scattering cross section of the target, solar irradiance model, optical system aperture and transmittance and quantum efficiency model, and detection exposure time model.

5. The evaluation platform of claim 1, wherein, The imaging and relative motion effect model module includes: a pixel angular resolution model, a target relative angular velocity model, and an imaging trail length model.

6. The evaluation platform of claim 1, wherein, The detection criteria and simulation scheduling module samples data for each observation moment, including: calculating the relative geometric relationship between the satellite and the target, determining the illumination and ground shadow conditions, calculating the optical signal and signal-to-noise ratio, and calculating the imaging trail.

7. The evaluation platform according to claim 1, characterized in that, The capability index system includes: detection probability, minimum detectable target size, and the trend of detection capability changes at different orbital altitudes.

8. The evaluation platform according to any one of claims 1 to 7, characterized in that A method for designing and evaluating optical payload parameters for low-Earth orbit situational awareness satellites includes the following steps: S1. Start the evaluation platform and initialize the configuration parameters; S2. Set the track, load, and target size information, and sample the track period according to the time step; S3. Calculate the satellite position, solar direction, and payload orientation at the current moment to generate target parameters; S4. Based on the target parameters, if it is determined that the target is in the Earth's shadow area, the detection results are recorded directly. S5. If the target is determined to be outside the Earth's shadow area, calculate the laser signal, relative velocity, trailing image, and signal-to-noise ratio (SNR). S6. If SNR ≥ threshold and ghosting ≤ threshold, mark as successful detection; otherwise, mark as undetected. S7. Record the detection results, and repeat S3-S6 to detect at the next moment. S8. Statistical analysis of the detection results, calculation of performance indicators, generation of output files, and termination of the detection.

9. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps of the method as described in claim 8.

10. A non-transitory computer-readable storage medium having stored thereon a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the method as described in claim 8.

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