A simulation image display method and system based on electronic chart

Abstract

The present invention belongs to the field of marine navigation technology. The present invention provides a simulation image display method and system based on electronic nautical charts, including: acquiring radar data, obtaining a feature matching value based on comparative analysis and processing of radar data and ocean information data, comparing the feature matching value with a feature matching threshold, generating a matching deviation signal if the feature matching value is less than the feature matching threshold, fusing radar data and ocean information data for unmatched sub-sea areas, analyzing the fused area to obtain a deviation degree value, comparing the deviation degree value with the deviation degree threshold, marking the analysis area as a deviation area if the deviation degree value is greater than or equal to the deviation degree threshold, acquiring a ship's running path, comparing the ship's running path with a re-screened deviation area, and displaying a simulation image of a key area to enable the ship to operate normally.

Description

Technical Field

[0001] The invention belongs to the field of marine navigation technology, and in particular to a simulation image display method and system based on electronic nautical charts. Background Art

[0002] Traditional electronic nautical charts mainly provide static marine geographic information. Although they provide a basic navigation basis for navigation, they are insufficient in dynamic environment simulation, real-time data fusion and immersive experience. With the continuous advancement of navigation technology, higher requirements are placed on the real-time, interactivity and realism of electronic nautical charts. Therefore, it is particularly important to develop an electronic nautical chart simulation display system and method that can comprehensively display the marine environment, ship dynamics and weather conditions.

[0003] In the above-mentioned prior art, the electronic chart is displayed as an image by loading selected chart data, displaying the chart in multiple windows, synchronously locating the position of the ship on the chart, zooming and panning. However, in the above-mentioned prior art, there is a lack of radar detection of the ocean information data of the electronic chart to determine the accuracy of the information of the electronic chart, and in the case of low accuracy of the electronic chart information, there is a lack of simulated image display of potential risks, which cannot guarantee the safety and stability of the ship during navigation and cannot enable the ship to operate normally and efficiently.

[0004] To this end, the present invention provides a method and system for displaying a simulated image based on an electronic nautical chart. Summary of the invention

[0005] In order to make up for the deficiencies of the prior art, at least one technical problem raised in the background technology is solved.

[0006] The technical solution adopted by the present invention to solve the technical problem is: a simulation image display method based on an electronic nautical chart, comprising:

[0007] Using radar signal simulation technology to simulate the process of radar transmitting and receiving signals, the first phase of radar scanning of the sea area is carried out to obtain radar data;

[0008] A feature matching value is obtained based on comparative analysis of radar data and ocean information data, and the feature matching value is compared with a feature matching threshold. If the feature matching value is less than the feature matching threshold, a matching deviation signal is generated;

[0009] Based on the matching deviation signal, the radar data and ocean information data are fused for the unmatched sub-sea area, and the fused area is divided into several analysis areas. The analysis areas are analyzed to obtain the proportion of non-overlapping features and the deviation value of non-overlapping features.

[0010] The proportion of the number of non-overlapping features and the deviation value of the non-overlapping features are processed to obtain a deviation degree value, and the deviation degree value is compared with a deviation degree threshold. If the deviation degree value is greater than or equal to the deviation degree threshold, the analysis area is marked as a deviation area;

[0011] Obtain the ship's running path, compare the ship's running path with the re-screened deviation area, obtain the key area, and display the key area in a simulated image to ensure the normal operation of the ship;

[0012] As a further technical solution of the present invention, a simulation image display method based on electronic nautical chart is provided:

[0013] The method for obtaining the feature matching value is as follows:

[0014] The effective sub-sea area number ratio and the obstacle number ratio are summed to obtain the obstacle range value, and the obstacle range value is marked as FW;

[0015] All obstacle matching deviation ratios are summed and averaged to obtain the obstacle matching deviation value, and the obstacle matching deviation value is marked as PC;

[0016] The obstacle range value FW and the obstacle matching deviation value PC are processed to obtain the feature matching value PD;

[0017] As a further technical solution of the present invention, a simulation image display method based on electronic nautical chart is provided:

[0018] The obstacle quantity ratio is obtained as follows:

[0019] All obstacle matching values ​​are summed up and averaged to obtain the obstacle matching mean value, and the obstacle matching mean value is ratio-calculated with the number of all obstacles in the ocean information data to obtain the obstacle number ratio;

[0020] As a further technical solution of the present invention, a simulation image display method based on electronic nautical chart is provided:

[0021] The method for obtaining the effective sub-sea area quantity ratio is as follows:

[0022] The characteristic information of obstacles in the characteristic database is divided into several sub-sea areas according to the sea area. According to the division of the sub-sea areas, the radar data is matched with each sub-sea area to obtain the obstacle matching value;

[0023] The obstacle matching value is compared with the obstacle matching threshold. The specific comparison process is as follows:

[0024] If the obstacle matching value is greater than or equal to the obstacle matching threshold, the sub-sea area is marked as a valid sub-sea area;

[0025] If the obstacle matching value is less than the obstacle matching threshold, the sub-sea area is marked as an invalid sub-sea area;

[0026] Count the number of all valid sub-sea areas, calculate the ratio of the number of all valid sub-sea areas to the number of all sub-sea areas, and obtain the ratio of the number of valid sub-sea areas;

[0027] As a further technical solution of the present invention, a simulation image display method based on electronic nautical chart is provided:

[0028] The obstacle matching deviation value PC is obtained as follows:

[0029] The obstacle matching value is calculated by difference with the obstacle matching mean, and the absolute value is taken to obtain the obstacle matching deviation value; the obstacle matching deviation value is calculated by ratio with the obstacle matching mean to obtain the obstacle matching deviation ratio; all obstacle matching deviation ratios are summed and the average is taken to obtain the obstacle matching deviation value, and the obstacle matching deviation value is marked as PC;

[0030] As a further technical solution of the present invention, a simulation image display method based on electronic nautical chart is provided:

[0031] The deviation degree value is obtained in the following manner:

[0032] The weighted sum of the proportion of non-overlapping features and the non-overlapping feature deviation value is obtained to obtain the deviation degree value;

[0033] As a further technical solution of the present invention, a simulation image display method based on electronic nautical chart is provided:

[0034] The method for obtaining the proportion of the number of non-overlapping features is as follows:

[0035] The registered radar data and ocean information data are superimposed to obtain the fused area;

[0036] Divide the fused area into several analysis areas, and analyze the analysis areas;

[0037] Based on any analysis area;

[0038] Count the number of non-overlapping features in radar data and ocean information data, and perform ratio processing with the matching number to obtain the non-overlapping feature value, and sum and average all non-overlapping feature values ​​to obtain the proportion of non-overlapping features;

[0039] As a further technical solution of the present invention, a simulation image display method based on electronic nautical chart is provided:

[0040] The method for obtaining the non-overlapping feature deviation value is as follows:

[0041] Measure the distances between the non-overlapping features and the radar data features and the ship, perform difference processing on the distance between the non-overlapping features and the ship and the distance between the radar data features and the ship, take the absolute value to obtain the distance difference, sum all the distance differences, take the average value, and obtain the average distance difference;

[0042] The distance difference is processed with the mean distance difference, and the absolute value is taken to obtain the distance deviation value, and the distance deviation value is used for the cosine similarity algorithm;

[0043] The distance deviation values ​​of the non-overlapping features with similarity between 0 and 1 are counted, and the ratio is calculated with the distance between the radar data feature and the ship to obtain the non-overlapping feature deviation value. All non-overlapping feature deviation values ​​are summed and averaged to obtain the non-overlapping feature deviation value;

[0044] As a further technical solution of the present invention, a simulation image display method based on electronic nautical chart is provided:

[0045] The method for displaying the simulated image in the key area is:

[0046] Compare the ship's operating path with the re-screened deviation area to obtain the key area;

[0047] Simulate image display of key areas;

[0048] Superimpose the registered radar data and the electronic chart data, display the superimposed image, render the superimposed image appropriately, such as adjusting the brightness and contrast to make the image clearer and more intuitive, and display the fused image to obtain a simulated image containing the radar data and the electronic chart data;

[0049] As a further technical solution of the present invention, a simulation image display system based on an electronic nautical chart comprises:

[0050] Preprocessing module: obtain ocean information data and preprocess the ocean information data;

[0051] Matching deviation signal generation module: using radar signal simulation technology to simulate the process of radar transmitting and receiving signals, perform the first phase of radar scanning on the sea area, obtain radar data, obtain feature matching values ​​based on comparative analysis of radar data and ocean information data, compare the feature matching values ​​with the feature matching threshold, and generate a matching deviation signal if the feature matching value is less than the feature matching threshold;

[0052] Matching deviation signal analysis module: Based on the matching deviation signal, the radar data and the ocean information data are fused for the non-matching sub-sea area, and the fused area is analyzed to obtain the proportion of the number of non-overlapping features and the non-overlapping feature deviation value. The proportion of the number of non-overlapping features and the non-overlapping feature deviation value are processed to obtain the deviation degree value, and the deviation degree value is compared with the deviation degree threshold. If the deviation degree value is greater than or equal to the deviation degree threshold, the analysis area is marked as a deviation area;

[0053] Analysis module: obtain the ship's running path, compare the ship's running path with the re-screened deviation area, obtain the key area, and display the simulated image of the key area to ensure the normal operation of the ship.

[0054] The beneficial effects of the present invention are as follows:

[0055] 1. Obtain ocean information data, pre-process the ocean information data, obtain radar data, obtain obstacle compatibility and water depth adaptability based on comparative analysis of radar data and ocean information data, obtain feature matching value based on summation calculation of obstacle compatibility and water depth adaptability, compare the feature matching value with the feature matching threshold, and generate a matching deviation signal if the feature matching value is less than the feature matching threshold. The present invention integrates ocean information data and radar data, calculates obstacle compatibility and water depth adaptability through pre-processing and comparative analysis, and obtains feature matching value, and compares it with the feature matching threshold. If the feature matching value is less than the feature matching threshold, a matching deviation signal is generated, thereby effectively improving the safety of marine activities and optimizing the utilization of marine resources and the level of emergency response;

[0056] 2. The present invention can accurately determine the non-overlapping feature-related indicators and obtain the deviation degree value through fusion analysis of specific sea area data based on feature matching deviation signals, effectively screen out the deviation area, and then determine the key area in combination with the ship's operation path comparison and perform simulated image display, which is helpful for ship operators to know the potential risks in advance, thereby performing simulated image display of potential risks, ensuring the safety and stability of the ship during navigation, enabling the ship to operate normally and efficiently, and reducing the occurrence of navigation accidents and delays due to data deviations or unknown risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] The present invention will be further described below in conjunction with the accompanying drawings.

[0058] Figure 1 This is a flowchart of the steps of a method for displaying a simulated image based on an electronic nautical chart as described in Example 1 of the present invention;

[0059] Figure 2 This is a flowchart of the steps of a simulation image display method based on an electronic nautical chart as described in Example 2 of the present invention;

[0060] Figure 3 It is a flowchart of a simulation image display system based on an electronic nautical chart as described in Example 3 of the present invention. DETAILED DESCRIPTION

[0061] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0062] Example 1

[0063] like Figure 1 A simulation image display method based on an electronic nautical chart according to an embodiment of the present invention includes:

[0064] Step 1: Use electronic nautical charts to obtain ocean information data and pre-process the ocean information data;

[0065] It should be noted that ocean information data includes the number and distance of obstacles, and ocean information data is usually stored in digital form;

[0066] Among them, the marine information data preprocessing process includes data cleaning, format conversion and noise removal to ensure the accuracy and consistency of the data;

[0067] Step 2: Use radar signal simulation technology to simulate the process of radar transmitting and receiving signals, perform the first phase of radar scanning on the sea area, obtain radar data, obtain feature matching values ​​based on comparative analysis of radar data and ocean information data, compare the feature matching values ​​with the feature matching threshold, and generate a matching deviation signal if the feature matching value is less than the feature matching threshold;

[0068] The meaning of radar data is: radar detects obstacles along the sea surface at the center of the ship, and radar data includes the number and distance of obstacles;

[0069] It needs to be explained that the radar determines the detected obstacle in the following way: when the radar is detecting an obstacle in the sea area, if the detected obstacle is on the water surface and it hinders the ship from continuing to sail, it is determined to be an obstacle; if the detected obstacle is under the water surface and the height of the ship's draft is greater than the height of the detected obstacle from the water surface, the detected obstacle is determined to be an obstacle;

[0070] Fuse simulated radar data with ocean information data, map radar signals onto electronic charts, and form radar images;

[0071] Matching radar data with oceanographic information data;

[0072] Extract the characteristic information of all obstacles in the ocean information data and summarize them into the same characteristic library, and compare the characteristic information of obstacles in the radar data with the characteristic library;

[0073] Specifically, the characteristic information of obstacles in the characteristic database is divided according to the sea area to obtain a number of sub-sea areas. According to the division of the sub-sea areas, the radar data is matched with the sub-sea areas respectively to obtain the obstacle matching value;

[0074] The obstacle matching value is compared with the obstacle matching threshold. The specific comparison process is as follows:

[0075] If the obstacle matching value is greater than or equal to the obstacle matching threshold, the sub-sea area is marked as a valid sub-sea area;

[0076] If the obstacle matching value is less than the obstacle matching threshold, the sub-sea area is marked as an invalid sub-sea area;

[0077] Count the number of all valid sub-sea areas, calculate the ratio of the number of all valid sub-sea areas to the number of all sub-sea areas, and obtain the ratio of the number of valid sub-sea areas;

[0078] All obstacle matching values ​​are summed up and averaged to obtain the obstacle matching mean value, and the obstacle matching mean value is ratio-calculated with the number of all obstacles in the ocean information data to obtain the obstacle number ratio;

[0079] The effective sub-sea area number ratio and the obstacle number ratio are summed to obtain the obstacle range value, and the obstacle range value is marked as FW;

[0080] It should be noted that the obstacle range value FW reflects the quantitative index of the matching degree of obstacles between radar data and ocean information data. The larger the obstacle range value FW is, the higher the matching degree of obstacles between radar data and ocean information data is. On the contrary, the smaller the obstacle range value FW is, the lower the matching degree of obstacles between radar data and ocean information data is.

[0081] Specifically, the obstacle matching value and the obstacle matching mean are difference calculated, and the absolute value is taken to obtain the obstacle matching deviation value, the obstacle matching deviation value and the obstacle matching mean are ratio calculated to obtain the obstacle matching deviation ratio, all obstacle matching deviation ratios are summed and averaged to obtain the obstacle matching deviation value, and the obstacle matching deviation value is marked as PC;

[0082] The obstacle range value FW and the obstacle matching deviation value PC are processed by data, and the formula The characteristic matching value PD is calculated, where s1 and s2 are both preset proportional coefficients;

[0083] It should be noted that the feature matching value reflects the quantitative index of the matching degree between radar data and ocean information data. The larger the feature matching value, the higher the matching degree between radar data and ocean information data. Conversely, the smaller the feature matching value, the lower the matching degree between radar data and ocean information data.

[0084] The feature matching value is compared with the feature matching threshold. The specific comparison process is as follows:

[0085] If the feature matching value is greater than or equal to the feature matching threshold, the sub-sea area is marked as a matching sub-sea area and no other processing is performed;

[0086] If the feature matching value is less than the feature matching threshold, the sub-sea area is marked as an unmatched sub-sea area, and a matching deviation signal is generated;

[0087] The technical solution of an embodiment of the present invention is: obtaining ocean information data, preprocessing the ocean information data, obtaining radar data, obtaining a feature matching value based on comparative analysis of the radar data and the ocean information data, comparing the feature matching value with a feature matching threshold, and generating a matching deviation signal if the feature matching value is less than the feature matching threshold. The present invention integrates ocean information data and radar data, calculates the feature matching value after preprocessing and comparative analysis, and compares it with the feature matching threshold. If the feature matching value is less than the feature matching threshold, a matching deviation signal is generated, thereby effectively improving the safety of ocean activities and optimizing the utilization of ocean resources and the level of emergency response.

[0088] Example 2

[0089] like Figure 2 As shown, based on Example 1, the mismatched sub-areas are analyzed. A simulation image display method based on an electronic nautical chart according to an embodiment of the present invention includes:

[0090] Step 3: Based on the matching deviation signal, the radar data and the ocean information data are fused for the non-matching sub-sea area, and the fused area is analyzed to obtain the proportion of the number of non-overlapping features and the deviation value of the non-overlapping features, and the proportion of the number of non-overlapping features and the deviation value of the non-overlapping features are processed to obtain the deviation degree value, and the deviation degree value is compared with the deviation degree threshold. If the deviation degree value is greater than or equal to the deviation degree threshold, the analysis area is marked as a deviation area;

[0091] In some embodiments, a feature matching algorithm is used to fuse radar data and ocean information data, a nearest neighbor matching algorithm is used to match features of ocean information data and radar data, the nearest feature is regarded as a match, and a method of bidirectional matching is performed on feature matching, that is, not only matching from radar features to electronic chart features, but also matching from electronic chart features to radar features. Only feature pairs that match in both directions are considered to be correct matches. The registered radar data and ocean information data are superimposed to obtain a fused area.

[0092] Divide the fused area into several analysis areas, and analyze the analysis areas;

[0093] Based on any analysis area;

[0094] Count the number of non-overlapping features in radar data and ocean information data, and perform ratio processing with the matching number to obtain the non-overlapping feature value, and sum and average all non-overlapping feature values ​​to obtain the proportion of non-overlapping features;

[0095] Measure the distances between the non-overlapping features and the radar data features and the ship, perform difference processing on the distance between the non-overlapping features and the ship and the distance between the radar data features and the ship, take the absolute value to obtain the distance difference, sum all the distance differences, take the average value, and obtain the average distance difference;

[0096] The distance difference is processed with the mean distance difference, and the absolute value is taken to obtain the distance deviation value, and the distance deviation value is used for the cosine similarity algorithm;

[0097] By formula Calculate the similarity of the distance deviation value , where A and B represent the distance deviation values ​​of different non-overlapping features, , They represent the modulus length of the distance deviation value respectively;

[0098] Similarity of distance deviation values The closer it is to 1, the closer the two distance deviation values ​​are;

[0099] The distance deviation values ​​of the non-overlapping features with similarity between 0 and 1 are counted, and the ratio is calculated with the distance between the radar data feature and the ship to obtain the non-overlapping feature deviation value. All non-overlapping feature deviation values ​​are summed and averaged to obtain the non-overlapping feature deviation value;

[0100] The weighted sum of the proportion of non-overlapping features and the non-overlapping feature deviation value is obtained to obtain the deviation degree value;

[0101] The deviation degree value is compared with the deviation degree threshold. The specific comparison process is as follows:

[0102] If the deviation degree value is less than the deviation degree threshold, no processing is performed;

[0103] If the deviation degree value is greater than or equal to the deviation degree threshold, the analysis image is marked as a deviation area;

[0104] Based on the deviation area, the second stage radar scan is performed on the deviation area to check the deviation area. The second stage radar scan means performing N radar scans on the deviation area to avoid errors caused by one scan.

[0105] Re-analyze the deviation area, screen the deviation area, and obtain a re-screened deviation area;

[0106] Step 4: Obtain the ship's running path, compare the ship's running path with the re-screened deviation area, obtain the key area, and display the key area in a simulated image to ensure the normal operation of the ship;

[0107] Compare the ship's operating path with the re-screened deviation area to obtain the key area;

[0108] It should be noted that the meaning of the key area is: the re-screening area passed by the ship's operation path. The purpose is to distinguish the re-screening area and display the simulated image of the area passed by the ship's operation path to ensure that the simulated image of the re-screening area is accurate and the ship's operation is safe;

[0109] Simulate image display of key areas;

[0110] The registered radar data and the electronic chart data are superimposed, and the superimposed image is displayed. The superimposed image is appropriately rendered, such as adjusting the brightness and contrast, to make the image clearer and more intuitive. The fused image is displayed to obtain a simulated image containing the radar data and the electronic chart data.

[0111] The technical solution of the embodiment of the present invention is: based on the feature matching deviation signal, the radar data and the ocean information data are fused for the mismatched sub-sea area, the fused area is analyzed, the non-overlapping feature quantity ratio and the non-overlapping feature deviation value are obtained, the non-overlapping feature quantity ratio and the non-overlapping feature deviation value are processed to obtain the deviation degree value, the deviation degree value and the deviation degree threshold are compared, if the deviation degree value is greater than or equal to the deviation degree threshold, the analysis image is marked as a deviation area, the ship's operation path is obtained, the ship's operation path is compared with the re-screened deviation area to obtain the key area, and the key area is simulated and displayed to enable the ship to operate normally. The present invention can accurately determine the non-overlapping feature-related indicators and obtain the deviation degree value by fusing and analyzing the specific sea area data based on the feature matching deviation signal, effectively screen out the deviation area, and then determine the key area in combination with the ship's operation path comparison and display the simulated image, which helps the ship operator to know the potential risks in advance, thereby displaying the potential risks in a simulated image, ensuring the safety and stability of the ship during navigation, enabling the ship to operate normally and efficiently, and reducing the occurrence of navigation accidents and delays caused by data deviation or unknown risks.

[0112] Example 3

[0113] like Figure 3 The embodiment of the present invention provides a simulation image display system based on an electronic nautical chart, comprising:

[0114] Preprocessing module: obtain ocean information data and preprocess the ocean information data;

[0115] Matching deviation signal generation module: using radar signal simulation technology to simulate the process of radar transmitting and receiving signals, perform the first phase of radar scanning on the sea area, obtain radar data, obtain feature matching values ​​based on comparative analysis of radar data and ocean information data, compare the feature matching values ​​with the feature matching threshold, and generate a matching deviation signal if the feature matching value is less than the feature matching threshold;

[0116] Matching deviation signal analysis module: Based on the matching deviation signal, the radar data and the ocean information data are fused for the non-matching sub-sea area, and the fused area is analyzed to obtain the proportion of the number of non-overlapping features and the non-overlapping feature deviation value. The proportion of the number of non-overlapping features and the non-overlapping feature deviation value are processed to obtain the deviation degree value, and the deviation degree value is compared with the deviation degree threshold. If the deviation degree value is greater than or equal to the deviation degree threshold, the analysis area is marked as a deviation area;

[0117] Analysis module: obtain the ship's running path, compare the ship's running path with the re-screened deviation area, obtain the key area, and display the simulated image of the key area to ensure the normal operation of the ship.

[0118] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for displaying a simulated image based on an electronic nautical chart, characterized in that: include: Using radar signal simulation technology to simulate the process of radar transmitting and receiving signals, the first phase of radar scanning of the sea area is carried out to obtain radar data; A feature matching value is obtained based on comparative analysis of radar data and ocean information data, and the feature matching value is compared with a feature matching threshold. If the feature matching value is less than the feature matching threshold, a matching deviation signal is generated; Based on the matching deviation signal, the radar data and ocean information data are fused for the unmatched sub-sea area, and the fused area is divided into several analysis areas. The analysis areas are analyzed to obtain the proportion of non-overlapping features and the deviation value of non-overlapping features. The method for obtaining the non-overlapping feature deviation value is as follows: Measure the distances between the non-overlapping features and the radar data features and the ship, perform difference processing on the distance between the non-overlapping features and the ship and the distance between the radar data features and the ship, take the absolute value to obtain the distance difference, sum all the distance differences, take the average value, and obtain the average distance difference; The distance difference is processed with the average distance difference, and the absolute value is taken to obtain the distance deviation value, and the distance deviation value is used for the cosine similarity algorithm; The distance deviation values ​​of the non-overlapping features with similarity between 0 and 1 are counted, and the ratio is calculated with the distance between the radar data feature and the ship to obtain the non-overlapping feature deviation value. All non-overlapping feature deviation values ​​are summed and averaged to obtain the non-overlapping feature deviation value; The proportion of the number of non-overlapping features and the deviation value of the non-overlapping features are processed to obtain a deviation degree value, and the deviation degree value is compared with a deviation degree threshold. If the deviation degree value is greater than or equal to the deviation degree threshold, the analysis area is marked as a deviation area; The ship's running path is obtained, and the ship's running path is compared with the re-screened deviation area to obtain the key area, and a simulated image display is performed on the key area to ensure the normal operation of the ship.

2. The method for displaying a simulated image based on an electronic nautical chart according to claim 1, characterized in that: The method for obtaining the feature matching value is as follows: The effective sub-sea area number ratio and the obstacle number ratio are summed to obtain the obstacle range value, and the obstacle range value is marked as FW; All obstacle matching deviation ratios are summed and averaged to obtain the obstacle matching deviation value, and the obstacle matching deviation value is marked as PC; The obstacle range value FW and the obstacle matching deviation value PC are processed to obtain the feature matching value PD.

3. The method for displaying a simulated image based on an electronic nautical chart according to claim 2, characterized in that: The obstacle quantity ratio is obtained as follows: All obstacle matching values ​​are summed up and averaged to obtain the obstacle matching mean, and the obstacle matching mean is ratio-calculated with the number of all obstacles in the ocean information data to obtain the obstacle number ratio.

4. The method for displaying a simulated image based on an electronic nautical chart according to claim 2, characterized in that: The method for obtaining the effective sub-sea area quantity ratio is as follows: The characteristic information of obstacles in the characteristic database is divided into several sub-sea areas according to the sea area. According to the division of the sub-sea areas, the radar data is matched with each sub-sea area to obtain the obstacle matching value; The obstacle matching value is compared with the obstacle matching threshold. The specific comparison process is as follows: If the obstacle matching value is greater than or equal to the obstacle matching threshold, the sub-sea area is marked as a valid sub-sea area; If the obstacle matching value is less than the obstacle matching threshold, the sub-sea area is marked as an invalid sub-sea area; The number of all valid sub-sea areas is counted, and the ratio of the number of all valid sub-sea areas to the number of all sub-sea areas is calculated to obtain the ratio of the number of valid sub-sea areas.

5. The method for displaying a simulated image based on an electronic nautical chart according to claim 2, characterized in that: The obstacle matching deviation value PC is obtained as follows: The difference between the obstacle matching value and the obstacle matching mean is calculated, and the absolute value is taken to obtain the obstacle matching deviation value. The ratio of the obstacle matching deviation value to the obstacle matching mean is calculated to obtain the obstacle matching deviation ratio. All obstacle matching deviation ratios are summed and the average is taken to obtain the obstacle matching deviation value, and the obstacle matching deviation value is marked as PC.

6. The method for displaying a simulated image based on an electronic nautical chart according to claim 1, characterized in that: The deviation degree value is obtained in the following manner: The deviation degree value is obtained by weighted summing the proportion of non-overlapping features and the non-overlapping feature deviation value.

7. The method for displaying a simulated image based on an electronic nautical chart according to claim 6, characterized in that: The method for obtaining the proportion of the number of non-overlapping features is as follows: The registered radar data and ocean information data are superimposed to obtain the fused area; Divide the fused area into several analysis areas, and analyze the analysis areas; Based on any analysis area; The number of non-overlapping features in radar data and ocean information data is counted and ratioed with the matching number to obtain the non-overlapping feature value. All non-overlapping feature values ​​are summed and averaged to obtain the proportion of non-overlapping features.

8. The method for displaying a simulated image based on an electronic nautical chart according to claim 1, characterized in that: The method for displaying the simulated image in the key area is: Compare the ship's operating path with the re-screened deviation area to obtain the key area; Simulate image display of key areas; The registered radar data and electronic chart data are superimposed, and the superimposed image is displayed. The superimposed image is appropriately rendered, such as adjusting the brightness and contrast to make the image clearer and more intuitive. The fused image is displayed to obtain a simulated image containing the radar data and the electronic chart data.

9. A simulation image display system based on electronic nautical chart, characterized in that: include: Preprocessing module: obtain ocean information data and preprocess the ocean information data; Matching deviation signal generation module: using radar signal simulation technology to simulate the process of radar transmitting and receiving signals, perform the first phase of radar scanning on the sea area, obtain radar data, obtain feature matching values ​​based on comparative analysis of radar data and ocean information data, compare the feature matching values ​​with the feature matching threshold, and generate a matching deviation signal if the feature matching value is less than the feature matching threshold; Matching deviation signal analysis module: Based on the matching deviation signal, the radar data and the ocean information data are fused for the non-matching sub-sea area, and the fused area is analyzed to obtain the proportion of the number of non-overlapping features and the non-overlapping feature deviation value. The proportion of the number of non-overlapping features and the non-overlapping feature deviation value are processed to obtain the deviation degree value, and the deviation degree value is compared with the deviation degree threshold. If the deviation degree value is greater than or equal to the deviation degree threshold, the analysis area is marked as a deviation area; The method for obtaining the non-overlapping feature deviation value is as follows: Measure the distances between the non-overlapping features and the radar data features and the ship, perform difference processing on the distance between the non-overlapping features and the ship and the distance between the radar data features and the ship, take the absolute value to obtain the distance difference, sum all the distance differences, take the average value, and obtain the average distance difference; The distance difference is processed with the average distance difference, and the absolute value is taken to obtain the distance deviation value, and the distance deviation value is used for the cosine similarity algorithm; The distance deviation values ​​of the non-overlapping features with similarity between 0 and 1 are counted, and the ratio is calculated with the distance between the radar data feature and the ship to obtain the non-overlapping feature deviation value. All non-overlapping feature deviation values ​​are summed and averaged to obtain the non-overlapping feature deviation value; Analysis module: obtain the ship's running path, compare the ship's running path with the re-screened deviation area, obtain the key area, and display the simulated image of the key area to ensure the normal operation of the ship.

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