A method and system for virtual simulation of a marine radar

Abstract

This invention discloses a virtual simulation method and system for marine radar, comprising the following steps: constructing a virtual test environment consistent with the real marine environment, including an unmanned vessel, marine radar, and maritime targets; using a quaternion calculation method to transform measurements in the local coordinate system of the virtual radar to the world coordinate system; determining the radar field of view through horizontal and vertical scanning coverage; realizing simulated ray tracing and collision detection of the marine radar beam; calculating echo distance and angle, calculating echo intensity, and generating standardized radar echo data records; dynamically adjusting the echo intensity through adjustable gain control and range compensation mechanisms, and mapping the echo data to a color space; persistently storing and time-attenuating the echo data to simulate radar afterglow effects; and drawing range rings, azimuth markers, and dynamic scan lines on the radar display interface to construct a complete radar visualization system.

Description

Technical Field

[0001] This invention belongs to the field of virtual simulation technology for maritime navigation equipment, and relates to a virtual simulation method and system for marine radar, providing key technical support for the virtual testing, training and evaluation of ship navigation systems. Background Technology

[0002] Marine radar is a critical piece of equipment for ship navigation safety, playing an irreplaceable role in maritime navigation, collision avoidance, and object identification. Traditional marine radar operates based on the principle of transmitting, reflecting, and receiving radio frequency signals, detecting the distance, bearing, and size of surrounding objects by measuring the round-trip time and intensity changes of microwave signals. With the development of virtual simulation technology, simulating the operation of marine radar in computer virtual environments has become increasingly important, with applications including crew training, radar system development and testing, and navigation plan evaluation.

[0003] Currently, existing virtual simulation systems for marine radar face several key technical challenges: First, traditional radar simulation methods often simplify signal reflection characteristics, neglecting the differences in radar wave reflection caused by different materials, leading to significant discrepancies between simulation results and actual radar echoes. Second, existing technologies struggle to accurately simulate the unique "afterglow" effect of marine radar, a persistent echo display crucial for operators to identify moving target trajectories. Furthermore, existing marine radar simulation systems tend to oversimplify vertical beam characteristics, typically using a single ray to represent the entire vertical beam area, failing to accurately reflect the energy distribution and detection characteristics of a real radar beam in the vertical direction. A real marine radar's vertical beam typically has a certain width (approximately 20-25 degrees), within which targets can be detected, but the echo intensity varies depending on the target's position within the beam.

[0004] In the field of marine radar display, traditional simulation methods often focus only on basic point echo displays, lacking comprehensive simulation of specialized radar display elements (such as range loops, azimuth markers, variable gain control, and long-range compensation). This results in a significant gap between virtual training environments and actual radar operating environments. Existing marine radar virtual display technologies also struggle to accurately simulate signal processing processes in actual radar systems, including gain adjustment and range compensation. These factors collectively affect the final display effect and readability of radar echoes. Summary of the Invention

[0005] To solve the above problems, the technical solution adopted by the present invention is: a virtual simulation method for marine radar, comprising the following steps: Step 1: Build a virtual test environment that is consistent with the real maritime environment, including unmanned ships, marine radar, and maritime targets, and add collision boxes to the models in the virtual test environment; Step 2: Create a marine radar class, set the key parameters of the radar, and generate a simulated radar beam that covers the entire field of view; Step 3: Using the quaternion calculation method, the measurements in the virtual radar local coordinate system are transformed into the world coordinate system to determine the emission direction and starting position of the simulated radar beam. Step 4: Based on the emission direction and starting point of the simulated ray of the marine radar beam, the radar field of view is determined by scanning coverage in both horizontal and vertical dimensions, thereby realizing the simulated ray tracking and collision detection of the marine radar beam. Step 5: When the simulated ray of the marine radar beam detects a collision, acquire the collision point information, calculate the echo distance and angle, and calculate the echo intensity based on the material properties of the object, the incident angle and the distance attenuation, and generate a standardized radar echo data record. Step 6: Dynamically adjust the echo intensity through adjustable gain control and distance compensation mechanism, and map the echo data to the color space; Step 7: Persistently store and time-attenuate the echo data to simulate radar afterglow effects; Step 8: Draw the range ring, azimuth markers, and dynamic scan lines on the radar display interface to build a complete radar visualization system.

[0006] Furthermore, the process of using quaternions to transform measurements in the local coordinate system of the virtual marine radar to the world coordinate system, thereby determining the emission direction and starting point of the simulated ray of the marine radar beam, is as follows: First, define the basic coordinate transformation relationship. In the local coordinate system, the ray origin is represented as: (2) in, This represents the starting coordinates of the ray in the radar's local coordinate system. This indicates the components of each axis of the starting point in the local coordinate system; The rotational attitude of marine radar is represented by a combination of quaternions: (3) in: For rotation angle, Normalized vector for rotation axis; Quaternions representing rotational attitude Represent the four components of a quaternion. The real part of the quaternion contains the main information about the rotation angle cosine. The imaginary part of the quaternion forms a vector that describes the direction of the rotation axis; Coordinate system transformations employ nested quaternion operations: (4) in, Let be the position of the ray's origin in the world coordinate system. The attitude quaternion of the marine radar relative to the ship's hull. The attitude quaternion of the ship relative to the world. It refers to the position of the ship's hull in the world coordinate system. To represent quaternion multiplication, This represents the conjugate of quaternions.

[0007] Furthermore: the process of determining the virtual maritime radar's field of view based on the emission direction and starting point position of the simulated ray from the virtual maritime radar beam, through scanning coverage in both horizontal and vertical dimensions, and realizing virtual maritime radar beam simulation ray tracking, is as follows: The horizontal scanning of the marine radar uses a uniform angle increment mechanism, and the horizontal scanning angle... The calculation formula is: (5) in, It is the current scan line number. The angle increment is determined by both the total number of scan lines and the coverage angle. The vertical beam distribution employs a uniform angle allocation strategy, with the vertical angle... The calculation formula is: (6) in, and These are the upper and lower boundary angles of the vertical beam, respectively. Channel number, This represents the total number of vertical channels; By combining horizontal and vertical angles, the direction vector of the simulated ray of the virtual marine radar beam in the local coordinate system is obtained. : (7) The direction vector is transformed into the world coordinate system through coordinate system transformation for beam simulation ray tracing calculations.

[0008] Furthermore: When the radar beam simulates a collision, the collision point information is acquired, the echo distance and angle are calculated, and the echo intensity is calculated based on the object's material properties, the incident angle, and the distance attenuation. The process of generating standardized radar echo data records is as follows: When a simulated radar beam collides with an object in the scene, the following information is first obtained: the 3D coordinates of the collision point, the normal vector of the collision surface, the straight-line distance from the ray's origin to the collision point, and the component references and related information of the colliding object. The echo distance is obtained by calculating the Euclidean distance from the starting point of the simulated radar beam to the point of impact: (8) in, The three-dimensional coordinates of the collision point These are the three-dimensional coordinates of the starting point of the simulated radar beam. The acquired distance data is standardized and mapped to the distance cells of the scan lines: (9) in The range resolution is determined by both the maximum detection range and the total number of range cells. (10) in: This represents the maximum detection range of the marine radar. This represents the total number of distance cells on the scan line. Multiple echoes from the same distance cell on the same scan line are merged. A maximum value retention strategy is adopted to establish a temporary echo data structure for storing and merging distance, angle and geometric information. Subsequently, the echo intensity is calculated based on the collision point information, and the material reflection coefficient is determined by the label recognition system; The incident angle influence factor is calculated using the dot product of the surface normal and the incident direction. : (11) in: The surface normal unit vector, Let be the direction vector of the incident ray; Distance decay factor A modified inverse square decay model is adopted: (12) in: For the target distance, The attenuation coefficient is constant; echo intensity The comprehensive calculation formula is as follows: (13) in: The baseline strength parameter can be adjusted through configuration. The calculated echo intensity values ​​are filled into the previously established radar echo data structure, ultimately forming a standardized radar echo dataset containing range, angle, cell index, and intensity information.

[0009] Furthermore, the process of dynamically adjusting the echo intensity through adjustable gain control and distance compensation mechanisms, and mapping the echo data to the color space, is as follows: The echoes on each scan line in the radar scan data are processed, and an adjustable gain factor is applied. For the original echo intensity Perform linear adjustment: (14) in: This indicates the adjusted echo intensity. This is the gain factor, with a range of... ; Long-range target enhancement coefficient Calculation: (15) in: To increase the starting distance, To enhance the coefficient, Here is the distance normalization parameter; d represents the current distance of the target echo. By combining gain and distance compensation, the final echo display intensity is calculated. : (16) The processed echo intensity is mapped onto a blue-green-yellow-red gradient chromatogram to achieve layered visualization: (17) in: These are the mapped RGB color values. This represents the echo intensity after final processing.

[0010] Furthermore: the process of dynamically adjusting the echo intensity and mapping the echo data to a color space to achieve persistent storage and time decay processing of the echo data, simulating the radar afterglow effect, is as follows: Establish a persistent echo data structure to store the angle, distance, intensity, color, and age information of each echo point; Set echo lifecycle parameters, including maximum lifecycle. and attenuation rate ; Perform the following steps during each radar scan update: Step 1: Update the attenuation state of existing echoes, increasing the echo age for each persistent echo: (18) in: Indicates the updated echo age; The intensity after decay is calculated using a time decay algorithm: (19) in: Echo age, For time step, The attenuation rate, Echo intensity; This represents the intensity of the echo attenuated at the i-th echo point. This represents the intensity of the i-th echo point before attenuation; Step 2: Remove elements below the intensity threshold or exceeding the maximum lifespan The echo point; Step 3: Determine the current scanning area and calculate the start and end angles of the scan band: (20) (twenty one) in The current scanning angle, This refers to the width of the scan band. Step 4: Add the valid echoes within the current scan band to persistent storage, retain only echoes with intensity exceeding the threshold, and set the initial age of each new echo to 0.

[0011] Furthermore, the process of drawing range rings, azimuth markers, and dynamic scan lines on the radar display interface to construct a complete radar visualization system is as follows: To create a circular radar display area, determine the center point and maximum radius, the specific process is as follows: Draw orthogonal azimuth marker lines, starting from the center point and ending at the edge point of the corresponding direction, and add azimuth labels; Display persistent echo data: Step 3: Draw dynamic scan lines: A ray drawn from the center point to the current scanning angle represents the radar's real-time scanning position. Highlights are added to the beginning of the scan line to enhance the visual effect. Step 4: Display the completed target texture on the user interface to achieve real-time radar display.

[0012] Furthermore: The process of creating a circular radar display area and determining its center point and maximum radius is as follows: Construct basic radar display elements and draw multiple concentric circular range rings, the number of which is... radius of each distance ring The calculation is as follows: (twenty two) in: Distance ring index: 1 to , Maximum display radius; Add distance labels to each distance ring to display the actual distance. : (twenty three) in: This represents the maximum detection range of the radar.

[0013] Furthermore, the process of displaying persistent echo data is as follows: Convert each echo point from polar coordinates to screen coordinates. : (twenty four) (25) in Echo distance, For maximum detection range, For echo angle, The center point of the screen; The size of the display point is determined based on the echo intensity, and the brightness is adjusted based on the echo age. (26) (27) in: For the size of the real point, Based on the display point size, Echo intensity This is the intensity scaling factor. The brightness of the point. Echo age, For the maximum lifespan, Minimum brightness; A virtual simulation system for marine radar, comprising: The building module is used to build a virtual test environment that is consistent with the real maritime environment, including unmanned ships, marine radar, and maritime targets, and to add collision boxes to the models in the virtual test environment. The generation module is used to create marine radar classes, set key radar parameters, and generate simulated radar beams that cover the entire field of view. The conversion module is used to convert measurements in the virtual radar local coordinate system to the world coordinate system using quaternion calculation methods, thereby determining the emission direction and starting point of the simulated radar beam. Determination Module: Used to determine the radar field of view based on the emission direction and starting position of the simulated ray of the marine radar beam, through scanning coverage in both horizontal and vertical dimensions, so as to realize the simulated ray tracking and collision detection of the marine radar beam; Calculation module: When the simulated ray of the marine radar beam detects a collision, it acquires the collision point information, calculates the echo distance and angle, and calculates the echo intensity based on the material properties of the object, the incident angle and the distance attenuation, and generates standardized radar echo data records. Adjustment module: Used to dynamically adjust the echo intensity through adjustable gain control and distance compensation mechanism, and to map the echo data to the color space; Simulation module: used for persistent storage and time decay processing of echo data to simulate radar afterglow effects; Building Module: Draw range rings, azimuth markers, and dynamic scan lines on the radar display interface to build a complete radar visualization system.

[0014] This invention provides a virtual simulation method and system for marine radar, proposing a high-precision simulation method: based on ray tracing and collision detection technology, it simulates the transmission, scanning, and echo generation processes of marine radar beams. Coordinate transformation is achieved through quaternion calculations, and echo intensity is optimized by combining dynamic gain adjustment and range compensation, while simulating afterglow effects to ultimately generate realistic radar images. This method significantly improves the simulation accuracy and scene adaptability of virtual marine radar.

[0015] This method employs a multi-ray uniform sampling strategy to simulate the transmission and reception process of radar beams. Combined with incident angle calculations, it accurately simulates beam energy distribution while considering the reflection characteristics of different materials. This achieves complete coverage of the vertical beam detection range and accurately reproduces the unique display effects of marine radar, including echo afterglow, range loop, azimuth markers, and various signal processing characteristics. This inversion method not only improves the realism of virtual training but also provides a low-cost, high-efficiency simulation platform for radar system development and testing.

[0016] The present invention provides a virtual simulation method and system for marine radar, which has the following advantages: This invention simulates the working principle of marine radar in a game engine environment using ray tracing technology, and achieves precise spatial positioning by combining quaternion coordinate transformation, effectively restoring the propagation and reflection characteristics of radar waves. This method can accurately identify the reflection characteristics of different materials, precisely simulate the energy distribution of the radar's vertical beam, achieve realistic echo afterglow effects, and provide a visual interface that meets nautical standards, while also supporting dynamic adjustment of key parameters.

[0017] Compared with the prior art, the beneficial effects of the present invention are: This invention constructs a simulated marine radar environment that closely resembles real-world scenarios through virtual simulation. In this environment, the virtual marine radar simulates the operation of an actual marine radar, using ray tracing technology to detect collisions between the radar beam and objects in the environment. This not only overcomes the limitations of traditional mathematical models but also provides measurement results closer to those of real marine radar. This invention simulates the unique afterglow effect of marine radar, processing persistent echoes through a time-attenuation algorithm, enabling operators to identify moving targets through echo trajectories, significantly improving the realism and usability of radar displays. Simultaneously, the multi-ray sampling technology of this invention achieves accurate simulation of the vertical beam of the marine radar, more accurately reproducing the echo characteristics of targets at different altitudes, improving the comprehensiveness and accuracy of radar detection. This inversion method is not only suitable for ship navigation training but can also be applied to radar system development and testing, navigation safety analysis, and other fields, showing broad application prospects. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a flowchart of the method of the present invention; Figure 2 For virtual navigation scenes in UE; Figure 3 The diagram shows the display interface of a marine radar, where (a) the dynamic scan line is located in the northeast, (b) the dynamic scan line is located in the southeast, (c) the dynamic scan line is located in the southwest, and (d) the dynamic scan line is located in the northwest. Detailed Implementation

[0020] It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Figure 1 This is a flowchart of the method of the present invention; Figure 2 For virtual navigation scenes in UE; This invention relates to a virtual simulation method and system for marine radar. It proposes a high-precision simulation method: a virtual test scenario is constructed in Unreal Engine (UE) software using scene virtualization, and a virtual marine radar is deployed within this virtual test environment. Based on ray tracing and collision detection technologies, the transmission, scanning, and echo generation processes of the marine radar beam are simulated. Coordinate transformation is achieved through quaternion calculations, and the echo intensity is optimized by combining dynamic gain adjustment and range compensation. The afterglow effect is simulated, ultimately generating a realistic radar image.

[0023] The method specifically includes the following steps: Step 1: Use 3D modeling software to build models including unmanned ships, marine radar, and maritime targets, and then use 3ds Max software to convert the format to FBX and export it. Import the FBX format model into Unreal Engine software and build a virtual test environment that matches the real marine environment. Add collision boxes to the model in the virtual test environment. Step 2: Create a marine radar class based on the Actor component and set the key parameters of the radar, including the number of vertical channels, maximum detection range, minimum detection range, number of range cells, vertical beamwidth, horizontal beamwidth, angle increment, total number of scan lines, default intensity and other basic parameters. Through these parameters, generate a simulated radar beam that covers the entire field of view. Step 3: Using the quaternion calculation method, the measurements in the virtual radar local coordinate system are transformed into the world coordinate system to determine the emission direction and starting position of the simulated radar beam. Step 4: Based on the emission direction and starting point of the virtual marine radar beam simulation ray, the radar field of view is determined by scanning coverage in both horizontal and vertical dimensions, thereby realizing virtual marine radar beam simulation ray tracking and collision detection. Step 5: When the virtual marine radar beam simulates a collision, it acquires the collision point information, calculates the echo distance and angle, and calculates the echo intensity based on the object's material properties, incident angle, and distance attenuation, generating a standardized radar echo data record. Step 6: Dynamically adjust the echo intensity through adjustable gain control and distance compensation mechanism, and map the echo data to the color space; Step 7: Persistently store and time-attenuate the echo data to simulate radar afterglow effects; Step 8: Draw the range ring, azimuth markers, and dynamic scan lines on the radar display interface to build a complete radar visualization system.

[0024] Steps 1, 2, 3, 4, 5, 6, 7, and 8 are executed sequentially. The process of using quaternions to transform measurements in the local coordinate system of the virtual maritime radar to the world coordinate system, thereby determining the emission direction and starting point of the simulated beam of the virtual maritime radar, is as follows: Ray tracing and collision detection methods are used to determine whether a ray collides with a virtual obstacle. If no collision occurs, it indicates that there is no obstacle in that direction or that the obstacle is outside the detection range of the marine radar. If a collision is detected, the coordinates of the collision point are stored, representing the location of the obstacle as measured by the marine radar.

[0025] Spatial positioning of marine radar rays is represented by ray parameter equations: (1) in, Represents any point on the ray. It is the starting point of the rays. It is a distance parameter. It is the direction vector of the ray; in the application scenario of marine lidar, the starting point This represents the position of the marine radar in the world coordinate system, while the direction vector... This is determined by the scanning angle of the marine radar.

[0026] In practical marine radar systems, the situation is more complex. Since the radar is mounted on the ship's hull, its position and attitude constantly change with the ship's movement. This necessitates establishing a precise coordinate transformation system to convert measurements from the radar's local coordinate system to the global coordinate system. This transformation process needs to consider two aspects: first, the radar's installation position and attitude relative to the ship's hull; and second, the ship's position and attitude in the global coordinate system.

[0027] To achieve accurate coordinate transformations, we employ a quaternion-based computational method. Compared to Euler angles, quaternions avoid gimbal lock and provide better numerical stability. First, we define the basic coordinate transformation relationships: The ray origin in the local coordinate system is represented as: (2) in, This represents the starting coordinates of the ray in the radar's local coordinate system. This indicates the components of each axis of the starting point in the local coordinate system; The rotational attitude of marine radar is represented by a combination of quaternions: (3) in: For rotation angle, Let be the rotation axis normalized vector; where, Quaternions representing rotational attitude Represent the four components of a quaternion. The real part of the quaternion contains the main information about the rotation angle cosine. The imaginary part of the quaternion forms a vector that describes the direction of the rotation axis.

[0028] Coordinate system transformations employ nested quaternion operations: (4) in, Let be the position of the ray's origin in the world coordinate system. The attitude quaternion of the marine radar relative to the ship's hull. The attitude quaternion of the ship relative to the world. It refers to the position of the ship's hull in the world coordinate system. To represent quaternion multiplication, This represents the conjugate of quaternions.

[0029] After determining the starting point of the beam, based on the emission direction and starting point position of the simulated ray of the virtual maritime radar beam, the field of view of the virtual maritime radar is determined by scanning coverage in both horizontal and vertical dimensions. The process of ray tracing the simulated ray of the virtual maritime radar beam is as follows: The horizontal scanning of the marine radar uses a uniform angle increment mechanism, and the horizontal scanning angle... The calculation formula is: (5) in, It is the current scan line number. The angle increment is determined by both the total number of scan lines and the coverage angle. The vertical beam distribution employs a uniform angle allocation strategy, with the vertical angle... The calculation formula is: (6) in, and These are the upper and lower boundary angles of the vertical beam, respectively. Channel number, This represents the total number of vertical channels.

[0030] By combining horizontal and vertical angles, the direction vector of the marine radar beam in the local coordinate system is obtained. : (7) This direction vector needs to be transformed into the world coordinate system through the coordinate system transformation introduced earlier before it can be used for ray beam tracking calculations.

[0031] This vertical multi-channel design significantly improves the accuracy and coverage of radar detection. Compared to traditional single-horizontal-plane scanning methods, this method can accurately reflect the energy distribution and detection characteristics of the actual radar beam in the vertical direction.

[0032] After implementing beam tracking for the virtual marine radar, when the simulated ray of the virtual radar beam detects a collision, the collision point information is acquired, the echo distance and angle are calculated, and the echo intensity is calculated based on the object's material properties, incident angle, and distance attenuation. The process of generating standardized radar echo data records is as follows: When a ray collides with an object in the scene, the following information is first obtained: the 3D coordinates of the collision point, the normal vector of the collision surface, the straight-line distance from the ray's origin to the collision point, and the component references and related information of the colliding object. The echo distance is obtained by calculating the Euclidean distance from the ray origin to the collision point: (8) in, The three-dimensional coordinates of the collision point These are the three-dimensional coordinates of the starting point of the simulated radar beam. The acquired distance data is standardized and mapped to the distance cells of the scan lines: (9) in The range resolution is determined by both the maximum detection range and the total number of range cells. (10) in This represents the maximum detection range of the marine radar. This represents the total number of distance cells on the scan line. Multiple echoes from the same distance cell on the same scan line are merged using a maximum value retention strategy. To this end, a temporary echo data structure is created to store and merge geometric information such as distance and angle. Subsequently, the echo intensity is calculated based on the collision point information. The material reflection characteristics are determined by a label recognition system. When the material label is identified as a ship, the reflection coefficient is... The value is 0.4, and the reflectance is set when the material label is identified as a float. The value is 0.3, which represents the reflectance coefficient when the material label is identified as an island with vegetation cover. The value is 0.1, and the reflectance coefficient is set when the material label is identified as sand. The value is 0.13. When the material label is identified as "other", the reflectance coefficient is... The value is 0.2; The incident angle influence factor is calculated using the dot product of the surface normal and the incident direction. : (11) in The surface normal unit vector, Let be the direction vector of the incident ray; Distance decay factor A modified inverse square decay model is adopted: (12) in For the target distance, The attenuation coefficient is constant; echo intensity The comprehensive calculation formula is as follows: (13) in This is the baseline strength parameter, which can be adjusted through configuration.

[0033] The calculated echo intensity values ​​are populated into the radar echo data structure, ultimately forming a standardized radar echo dataset containing range, angle, cell index, and intensity information. This method of calculating echo intensity based on physical characteristics enables more accurate simulation of the echo characteristics of targets with different materials, incident angles, and distances, significantly improving the realism and accuracy of maritime radar simulation. Particularly for targets with unique reflection characteristics, such as islands with vegetation and small steel boats, this method provides detection results that more closely resemble those of real radar.

[0034] After generating radar echo data, the echo intensity is dynamically adjusted through adjustable gain control and range compensation mechanisms, and the echo data is mapped to the color space as follows: The echoes on each scan line in the radar scan data are processed, and an adjustable gain factor is applied. For the original echo intensity Perform linear adjustment: (14) in: This is the gain factor, with a range of... ; This indicates the adjusted echo intensity; Long-range target enhancement coefficient Calculation: (15) in To increase the starting distance, To enhance the coefficient, Here is the distance normalization parameter; d represents the current distance of the target echo. By combining gain and distance compensation, the final echo display intensity is calculated. : (16) The processed echo intensity is mapped onto a blue-green-yellow-red gradient chromatogram to achieve layered visualization: (17) in These are the mapped RGB color values. This represents the echo intensity after final processing.

[0035] This invention achieves accurate simulation of the display effect of marine radar through this signal processing system. Adjustable gain control allows the operator to adjust the echo display intensity according to actual needs, long-range signal enhancement improves the visibility of distant targets, and color mapping processing provides intuitive visual distinction between echoes of different intensities. These features collectively improve the information transmission efficiency and user experience of the radar display, making the virtual radar feel closer to the real equipment.

[0036] After dynamically adjusting the echo intensity and mapping the echo data to a color space, the persistent storage and time decay processing of the echo data are achieved, simulating the radar afterglow effect as follows: Establish a persistent echo data structure to store the angle, distance, intensity, color, and age information of each echo point; Set echo lifecycle parameters, including maximum lifecycle. and attenuation rate ; Perform the following steps during each radar scan update: Step 1: Update the attenuation state of existing echoes, increasing the echo age for each persistent echo: (18) in: Indicates the updated echo age; The intensity after decay is calculated using a time decay algorithm: (19) in: Echo age (seconds) The time step (in seconds). The attenuation rate, Echo intensity; This represents the intensity of the echo attenuated at the i-th echo point. This represents the intensity of the i-th echo point before attenuation.

[0037] Step 2: Remove elements below the intensity threshold or exceeding the maximum lifespan The echo point; Step 3: Determine the current scanning area and calculate the start and end angles of the scan band: (20) (twenty one) in The current scanning angle, This refers to the width of the scan band. Step 4: Add the valid echoes within the current scan band to persistent storage, retain only echoes with intensity exceeding the threshold, and set the initial age of each new echo to 0.

[0038] Through this echo persistence and time decay processing, a realistic radar afterglow effect was successfully achieved. Compared to traditional real-time display methods, this technology can retain the target's historical trajectory information, making it easier for operators to judge the target's motion state and changing trends. Especially for the detection and tracking of moving targets, this technology provides richer time-series information, significantly improving the practicality and information value of the radar system.

[0039] After simulating radar afterglow, the process of drawing range rings, azimuth markers, and dynamic scan lines on the radar display interface to construct a complete radar visualization system is as follows: Create a circular radar display area, and determine the center point and maximum radius: Step 1: Constructing the basic radar display elements: Draw multiple concentric circular distance rings, the number of which is... The radius of each distance ring is calculated as follows: (twenty two) in For distance ring index (1 to ), Maximum display radius; Add distance labels to each distance ring to display the actual distance: (twenty three) in This represents the radar's maximum detection range. Draw orthogonal azimuth marker lines (N, E, S, W), starting from the center point and ending at the edge point of the corresponding direction, and add azimuth labels; Step 2: Display persistent echo data: Convert each echo point from polar coordinates to screen coordinates: (twenty four) (25) in Echo distance, For maximum detection range, For echo angle, The center point of the screen; The size of the display point is determined based on the echo intensity, and the brightness is adjusted based on the echo age. (26) (27) in For the size of the real point, Based on the display point size, Echo intensity This is the intensity scaling factor. The brightness of the point. Echo age, For the maximum lifespan, Minimum brightness; Step 3: Draw dynamic scan lines: A ray drawn from the center point to the current scanning angle represents the radar's real-time scanning position. Highlights are added to the beginning of the scan line to enhance the visual effect. Step 4: Display the completed target texture on the user interface to achieve real-time radar display.

[0040] This invention provides a visual experience highly consistent with real marine radar through this complete radar display interface system. The range ring and azimuth markers help operators quickly determine the target's position and distance, dynamic scan lines provide intuitive feedback on the radar's operational status, and changes in echo size and brightness enhance the readability and hierarchy of information. These elements together constitute a professional, intuitive, and information-rich radar display interface, significantly improving the practical value and training effectiveness of the virtual simulation system.

[0041] Using simulation software to run the basic process, the marine radar scanning process is updated in real time. The scan line rotates at a set speed, and the distance and orientation of obstacles change accordingly as the ship sails, thus achieving real-time perception of the surrounding environment.

[0042] Figure 3 The images show the display interface of a marine radar, with (a) a schematic diagram of the dynamic scan line in the northeast direction, (b) a schematic diagram of the dynamic scan line in the southeast direction, (c) a schematic diagram of the dynamic scan line in the southwest direction, and (d) a schematic diagram of the dynamic scan line in the northwest direction. These images demonstrate the complete radar interface, including echo points, range loops, azimuth markers, and scan lines. This intuitive visualization provides operators with rich environmental awareness information, effectively supporting navigation and obstacle avoidance decisions.

[0043] This visualization system enables virtual marine radar to accurately reproduce the display effect of real radar, providing real and reliable visual feedback for unmanned vessel navigation algorithm testing and personnel training.

[0044] 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 or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A virtual simulation method for marine radar, characterized in that: Includes the following steps: Step 1: Build a virtual test environment that is consistent with the real maritime environment, including unmanned ships, marine radar, and maritime targets, and add collision boxes to the models in the virtual test environment; Step 2: Create a marine radar class, set the key parameters of the radar, and generate a simulated radar beam that covers the entire field of view; Step 3: Using the quaternion calculation method, the measurements in the virtual radar local coordinate system are transformed into the world coordinate system to determine the emission direction and starting position of the simulated radar beam. Step 4: Based on the emission direction and starting point of the simulated ray of the marine radar beam, the radar field of view is determined by scanning coverage in both horizontal and vertical dimensions, thereby realizing the simulated ray tracking and collision detection of the marine radar beam. Step 5: When the simulated ray of the marine radar beam detects a collision, acquire the collision point information, calculate the echo distance and angle, and calculate the echo intensity based on the material properties of the object, the incident angle and the distance attenuation, and generate a standardized radar echo data record. Step 6: Dynamically adjust the echo intensity through adjustable gain control and distance compensation mechanism, and map the echo data to the color space; Step 7: Persistently store and time-attenuate the echo data to simulate radar afterglow effects; Step 8: Draw the range ring, azimuth markers, and dynamic scan lines on the radar display interface to build a complete radar visualization system.

2. The virtual simulation method and system for marine radar according to claim 1, characterized in that: The process of using quaternions to transform measurements in the local coordinate system of the virtual marine radar to the world coordinate system, thereby determining the emission direction and starting point of the simulated ray of the marine radar beam, is as follows: First, define the basic coordinate transformation relationship. In the local coordinate system, the ray origin is represented as: (2) in, This represents the starting coordinates of the ray in the radar's local coordinate system. This indicates the components of each axis of the starting point in the local coordinate system; The rotational attitude of marine radar is represented by a combination of quaternions: (3) in: For rotation angle, Normalized vector for rotation axis; Quaternions representing rotational attitude Represent the four components of a quaternion. The real part of the quaternion contains the main information about the rotation angle cosine. The imaginary part of the quaternion forms a vector that describes the direction of the rotation axis; Coordinate system transformations employ nested quaternion operations: (4) in, Let be the position of the ray's origin in the world coordinate system. The attitude quaternion of the marine radar relative to the ship's hull. The attitude quaternion of the ship relative to the world. It refers to the position of the ship's hull in the world coordinate system. To represent quaternion multiplication, This represents the conjugate of quaternions.

3. The virtual simulation method and system for marine radar according to claim 1, characterized in that: The process of tracing the virtual marine radar beam simulated ray by determining the field of view of the virtual marine radar based on the emission direction and starting position of the simulated ray using both horizontal and vertical scanning coverage is as follows: The horizontal scanning of the marine radar uses a uniform angle increment mechanism, and the horizontal scanning angle... The calculation formula is: （5） in, It is the current scan line number. The angle increment is determined by both the total number of scan lines and the coverage angle. The vertical beam distribution employs a uniform angle allocation strategy, with the vertical angle... The calculation formula is: (6) in, and These are the upper and lower boundary angles of the vertical beam, respectively. Channel number, This represents the total number of vertical channels; By combining horizontal and vertical angles, the direction vector of the simulated ray of the virtual marine radar beam in the local coordinate system is obtained. : (7) The direction vector is transformed into the world coordinate system through coordinate system transformation for beam simulation ray tracing calculations.

4. The virtual simulation method and system for marine radar according to claim 1, characterized in that: When a radar beam simulates a collision, it acquires the collision point information, calculates the echo distance and angle, and calculates the echo intensity based on the object's material properties, the incident angle, and distance attenuation. The process of generating standardized radar echo data records is as follows: When a simulated radar beam collides with an object in the scene, the following information is first obtained: the 3D coordinates of the collision point, the normal vector of the collision surface, the straight-line distance from the ray's origin to the collision point, and the component references and related information of the colliding object. The echo distance is obtained by calculating the Euclidean distance from the starting point of the simulated radar beam to the point of impact: (8) in, The three-dimensional coordinates of the collision point These are the three-dimensional coordinates of the starting point of the simulated radar beam. The acquired distance data is standardized and mapped to the distance cells of the scan lines: (9) in The range resolution is determined by both the maximum detection range and the total number of range cells. (10) in: This represents the maximum detection range of the marine radar. This represents the total number of distance cells on the scan line. Multiple echoes from the same distance cell on the same scan line are merged. A maximum value retention strategy is adopted to establish a temporary echo data structure for storing and merging distance, angle and geometric information. Subsequently, the echo intensity is calculated based on the collision point information, and the material reflection coefficient is determined by the label recognition system; The incident angle influence factor is calculated using the dot product of the surface normal and the incident direction. : (11) in: The surface normal unit vector, Let be the direction vector of the incident ray; Distance decay factor A modified inverse square decay model is adopted: (12) in: For the target distance, The attenuation coefficient is constant; echo intensity The comprehensive calculation formula is as follows: (13) in: The baseline strength parameter can be adjusted through configuration. The calculated echo intensity values ​​are filled into the previously established radar echo data structure, ultimately forming a standardized radar echo dataset containing range, angle, cell index, and intensity information.

5. The virtual simulation method and system for marine radar according to claim 1, characterized in that: The process of dynamically adjusting the echo intensity through adjustable gain control and distance compensation mechanisms, and mapping the echo data to the color space, is as follows: The echoes on each scan line in the radar scan data are processed, and an adjustable gain factor is applied. For the original echo intensity Perform linear adjustment: (14) in: This indicates the adjusted echo intensity. This is the gain factor, with a range of... ; Long-range target enhancement coefficient Calculation: (15) in: To increase the starting distance, To enhance the coefficient, Here is the distance normalization parameter; d represents the current distance of the target echo. By combining gain and distance compensation, the final echo display intensity is calculated. : (16) The processed echo intensity is mapped onto a blue-green-yellow-red gradient chromatogram to achieve layered visualization: (17) in: These are the mapped RGB color values. This represents the echo intensity after final processing.

6. The virtual simulation method and system for marine radar according to claim 1, characterized in that: The process of dynamically adjusting the echo intensity and mapping the echo data to a color space to achieve persistent storage and time decay processing of the echo data, simulating the radar afterglow effect, is as follows: Establish a persistent echo data structure to store the angle, distance, intensity, color, and age information of each echo point; Set echo lifecycle parameters, including maximum lifecycle. and attenuation rate ; Perform the following steps during each radar scan update: Step 1: Update the attenuation state of existing echoes, increasing the echo age for each persistent echo: (18) in: Indicates the updated echo age; The intensity after decay is calculated using a time decay algorithm: (19) in: Echo age, For time step, The attenuation rate, Echo intensity; This represents the intensity of the echo attenuated at the i-th echo point. This represents the intensity of the i-th echo point before attenuation; Step 2: Remove elements below the intensity threshold or exceeding the maximum lifespan The echo point; Step 3: Determine the current scanning area and calculate the start and end angles of the scan band: (20) (21) in The current scanning angle, This refers to the width of the scan band. Step 4: Add the valid echoes within the current scan band to persistent storage, retain only echoes with intensity exceeding the threshold, and set the initial age of each new echo to 0.

7. The virtual simulation method and system for marine radar according to claim 1, characterized in that: The process of drawing range rings, azimuth markers, and dynamic scan lines on the radar display interface to construct a complete radar visualization system is as follows: To create a circular radar display area, determine the center point and maximum radius, the specific process is as follows: Draw orthogonal azimuth marker lines, starting from the center point and ending at the edge point of the corresponding direction, and add azimuth labels; Display persistent echo data: Step 3: Draw dynamic scan lines: A ray drawn from the center point to the current scanning angle represents the radar's real-time scanning position. Highlights are added to the beginning of the scan line to enhance the visual effect. Step 4: Display the completed target texture on the user interface to achieve real-time radar display.

8. The virtual simulation method and system for marine radar according to claim 6, characterized in that: The process of creating a circular radar display area and determining its center point and maximum radius is as follows: Construct basic radar display elements and draw multiple concentric circular range rings, the number of which is... radius of each distance ring The calculation is as follows: (22) in: Distance ring index: 1 to , Maximum display radius; Add distance labels to each distance ring to display the actual distance. : (23) in: This represents the maximum detection range of the radar.

9. The virtual simulation method and system for marine radar according to claim 6, characterized in that: The process of displaying persistent echo data is as follows: Convert each echo point from polar coordinates to screen coordinates. : (24) (25) in Echo distance, For maximum detection range, For echo angle, The center point of the screen; The size of the display point is determined based on the echo intensity, and the brightness is adjusted based on the echo age. (26) (27) in: For the size of the real point, Based on the display point size, Echo intensity This is the intensity scaling factor. The brightness of the point. Echo age, For the maximum lifespan, This is the minimum brightness.

10. A virtual simulation system for marine radar, characterized in that: include: The building module is used to build a virtual test environment that is consistent with the real maritime environment, including unmanned ships, marine radar, and maritime targets, and to add collision boxes to the models in the virtual test environment. The generation module is used to create marine radar classes, set key radar parameters, and generate simulated radar beams that cover the entire field of view. The conversion module is used to convert measurements in the virtual radar local coordinate system to the world coordinate system using quaternion calculation methods, thereby determining the emission direction and starting point of the simulated radar beam. Determination Module: Used to determine the radar field of view based on the emission direction and starting position of the simulated ray of the marine radar beam, through scanning coverage in both horizontal and vertical dimensions, so as to realize the simulated ray tracking and collision detection of the marine radar beam; Calculation module: When the simulated ray of the marine radar beam detects a collision, it acquires the collision point information, calculates the echo distance and angle, and calculates the echo intensity based on the material properties of the object, the incident angle and the distance attenuation, and generates standardized radar echo data records. Adjustment module: Used to dynamically adjust the echo intensity through adjustable gain control and distance compensation mechanism, and to map the echo data to the color space; Simulation module: used for persistent storage and time decay processing of echo data to simulate radar afterglow effects; Building Module: Draw range rings, azimuth markers, and dynamic scan lines on the radar display interface to build a complete radar visualization system.

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