A rapid detection method for seabed heavy sand deposits based on shipborne towed combined measurement

Abstract

The present invention relates to the technical field of marine geological resource exploration, and specifically to a method for rapid detection of seabed heavy sand deposits based on ship-borne towed combined measurement, comprising the following steps: S1: connecting a towing body integrating a gamma spectrum detection component, a magnetic susceptibility detection component, and a pressure-bearing sealing structure to a ship-borne integrated control host via a cable; S2: acquiring gamma spectrum data and sediment magnetic susceptibility; S3: performing water depth pressure compensation correction on the gamma spectrum data and performing inclination correction on the magnetic susceptibility data; S4: converting the corrected gamma spectrum data into a radioactivity anomaly intensity map and converting the corrected magnetic susceptibility data into a magnetic susceptibility anomaly intensity map; and S5: performing spatial superposition to screen out heavy sand deposit target areas. The present invention, by integrating a multi-parameter detection and correction mechanism, achieves accurate identification and standardized output of abnormal areas of seabed heavy sand deposits, significantly improving the reliability and determination efficiency of near-bottom-layer resource detection.

Description

Technical Field

[0001] The present invention relates to the technical field of marine geological resource exploration, and in particular to a method for rapid detection of seabed heavy sand mines based on shipborne towed combined measurement. Background Art

[0002] In the process of seabed mineral resource exploration, heavy placer deposits (containing gold, iron, rare earth, etc.) have become an important exploration target for shallow seabed target resources due to their high economic value and clear occurrence characteristics. At present, the mainstream technical route is to carry out near-bottom-layer detection using shipborne measurement platforms combined with underwater towing equipment. The detection parameters mainly include physical field data such as radioactive gamma energy spectrum, magnetic susceptibility response, and conductivity. Among them, gamma energy spectrum is widely used internationally to reflect the enrichment characteristics of radioactive elements in heavy minerals, and magnetic susceptibility reflects the occurrence degree of magnetic minerals. The two are highly complementary in expressing the distribution characteristics of heavy placer deposits. However, traditional exploration methods are mostly based on single-parameter analysis, ignoring the quantitative identification of multi-parameter spatial overlap characteristics, resulting in large errors in target area determination. At the same time, current data processing methods often lack error control mechanisms such as compensation for gamma signal water depth attenuation and magnetic susceptibility attitude correction, which limits detection accuracy and practicality.

[0003] To address these issues, there is an urgent need to develop a rapid detection method for seafloor heavy sand deposits that integrates multi-parameter features and has real-time correction capabilities. On the one hand, it is necessary to perform spatial correlation analysis on radioactive and magnetic data to extract areas of overlap between the two parameters and avoid misjudgments caused by single-parameter anomalies. On the other hand, key technical links such as water depth compensation, inclination correction, and anomaly classification are required to improve the stability of detection data, regional comparability, and scientific target identification. Therefore, a rapid detection method for seafloor heavy sand deposits based on shipborne towed combined measurement was developed to address these issues. Summary of the Invention

[0004] Based on the above objectives, the present invention provides a method for rapid detection of seabed heavy sand deposits based on shipborne towed combined measurement.

[0005] A rapid detection method for seabed heavy sand deposits based on shipborne towed combined measurement includes the following steps:

[0006] S1: Connect the towed body, which integrates the gamma spectrum detection component, magnetic susceptibility detection component and pressure-bearing sealing structure, to the ship's integrated control host via a cable, and adjust the towed body to the preset seabed detection depth;

[0007] S2: Start the gamma spectrum detection component to obtain the total radioactive gamma channel count and uranium, thorium, and potassium content data in real time. At the same time, start the magnetic susceptibility detection component to obtain the sediment magnetic susceptibility and equipment inclination data in real time.

[0008] S3: Perform water depth pressure compensation correction on the gamma ray spectrum data obtained in S2, and perform inclination correction and external magnetic field interference shielding on the magnetic susceptibility data;

[0009] S4: Convert the corrected gamma spectrum data into a radioactivity anomaly intensity map, and convert the corrected magnetic susceptibility data into a magnetic susceptibility anomaly intensity map, both of which are marked with spatial coordinates at a scale of 1:10000;

[0010] S5: spatially superimpose the radioactivity anomaly intensity map and the magnetic susceptibility anomaly intensity map, extract the double-parameter anomaly overlap area, and screen out the heavy placer target area based on the preset threshold;

[0011] S6: Integrate the coordinates, radioactivity intensity and magnetic susceptibility intensity data of heavy placer targets into a standardized report.

[0012] Optionally, the S1 specifically includes:

[0013] S11: The towed vehicle, which integrates the gamma spectrum detection component, magnetic susceptibility detection component, and pressure-sealed structure, is connected to the shipboard integrated control host via a high-modulus polyethylene cable with a preset strength of 20kN. A directional connector and a quick-locking plug-in are provided at each end of the cable.

[0014] S12: The diving depth parameters are set on the onboard control host. The cable is released at a speed of 0.2 m / s through the automatic winch system. The current depth data of the towed body is monitored in real time through the pressure sensor and depth gauge integrated in the cable. The winch is automatically stopped when the towed body stably hovers at the preset detection layer 1.5 meters above the seabed.

[0015] S13: Synchronously start a hydrodynamic stabilization control unit through the control host, wherein the hydrodynamic stabilization control unit includes a double-wing stabilization fin and a counterweight adjustment assembly located at the trailing edge of the towed body, and is used to maintain the heading stability of the towed body and the attitude angle less than 2°.

[0016] Optionally, the S2 specifically includes:

[0017] S21: A start-up command is issued to the gamma spectrum detection component via the shipboard integrated control host. The gamma spectrum detection component includes a sodium iodide scintillation detector, a multi-channel analyzer, and a data transmission interface. After the detector is powered on and reaches an operating voltage of 750V, gamma spectrum data is collected within a 0.1 second time interval. The multi-channel analyzer analyzes the total channel count and the potassium, uranium, and thorium count values ​​corresponding to the 1.46 MeV, 1.76 MeV, and 2.61 MeV energy regions.

[0018] S22: Synchronously activate the magnetic susceptibility detection component, which consists of a three-axis low-frequency inductive magnetic susceptibility sensor array and a three-dimensional accelerometer. After activation, the component continuously collects sediment response signal changes at a frequency of 1 Hz, and combines the three-axis attitude angle data measured by the three-dimensional accelerometer to output the volume magnetic susceptibility value and the current device inclination angle data in real time;

[0019] S23: All collected data are transmitted back to the shipboard control host in real time through the cable data channel, and the gamma energy spectrum and magnetic susceptibility data streams are synchronously displayed on the control interface in a time-stamped manner.

[0020] Optionally, the S3 specifically includes:

[0021] S31: matching the gamma spectrum data and radioactive element count data in each energy region collected by the gamma spectrum detection component with the water depth information acquired in real time by the pressure sensor integrated in the towed body, compensating for the counting deviation of the gamma signal caused by energy attenuation in the water body based on the hydrostatic pressure parameter corresponding to the water depth, and obtaining depth-corrected radioactive gamma spectrum data;

[0022] S32: combining the raw volume magnetic susceptibility data collected by the magnetic susceptibility detection component with the attitude angle data obtained by the triaxial accelerometer, and performing geometric attitude correction on the magnetic susceptibility value according to the current tilt angle of the device in the x-axis and y-axis directions to eliminate magnetic response distortion caused by the attitude deviation of the towed body;

[0023] S33: The background magnetic field strength data of the sea area recorded by the shipboard control host is called to perform interference discrimination on the corrected magnetic susceptibility data, and the data exceeding the set magnetic field disturbance threshold range is filtered out.

[0024] Optionally, the S31 specifically includes:

[0025] S311: The gamma spectrum detection component acquires the raw gamma spectrum data within each 0.1 second time window , and receive the water depth data h of the towed body in real time;

[0026] S312: Based on the hydrostatic pressure conditions corresponding to the water depth and the energy attenuation characteristics of the water body on gamma rays, the original gamma spectrum data is compensated. The formula is: ,in, is the corrected gamma spectrum data, Represents the exponential compensation factor of water body for signal attenuation, where is the average attenuation coefficient of water to gamma rays, which is 0.045;

[0027] S313: Correcting the uranium, thorium, and potassium counts corresponding to all gamma energy regions according to the same depth compensation, and uniformly encoding and storing the correction results as a structured radioactivity spectrum data set.

[0028] Optionally, the S32 specifically includes:

[0029] S321: The three-axis accelerometer in the magnetic susceptibility detection component obtains the inclination angle data of the current towed body in the x-axis and y-axis directions in real time, which are recorded as and , in radians;

[0030] S322: Assume that the original volume susceptibility is , perform geometric posture correction on it, the specific formula is: ,in, is the corrected magnetic susceptibility, is the correction factor, which represents the projection ratio of the angle between the current attitude direction and the gravity direction;

[0031] S323: Mark the sampled data with a posture angle exceeding 0.35 radians as an unstable state, and remove the data of the marked portion.

[0032] Optionally, the S4 specifically includes:

[0033] S41: The corrected gamma spectrum data are normalized and interpolated according to the coordinates of the measuring point position, and the radioactivity intensity distribution field is generated in a unified spatial grid with a scale of 1:10000 using the inverse distance weighted algorithm; and the mean value of the regional background is calculated based on the statistical data. and standard deviation , set the gamma intensity value above The grid area is marked as the radioactive anomaly area, and the radioactive anomaly intensity map is output;

[0034] S42: The corrected magnetic susceptibility data are interpolated according to the spatial coordinates corresponding to the acquisition points, and the Kriging spatial interpolation algorithm is used to establish a continuous magnetic susceptibility distribution layer, and the background magnetic susceptibility mean is used to calculate the magnetic susceptibility distribution layer. and standard deviation Set the abnormal judgment threshold, and set the magnetic susceptibility value higher than The grid area is marked as the magnetic susceptibility anomaly area, and the magnetic susceptibility anomaly intensity map is output;

[0035] S43: Encode the layer metadata of the two anomaly intensity maps, including sampling time, spatial reference system, interpolation algorithm and anomaly level description, and export them in vector format.

[0036] Optionally, the S5 specifically includes:

[0037] S51: Import the radioactivity anomaly intensity map and magnetic susceptibility anomaly intensity map generated by S4 into the geological information processing platform, use a unified coordinate system for reprojection and grid alignment, and ensure that the two layers are completely matched in spatial dimensions;

[0038] S52: Use the layer overlay algorithm to perform pixel-level intersection operation on the two anomaly images and extract the anomaly images that meet the radioactivity intensity value at the same time. and magnetic susceptibility value The overlapping area is the abnormal overlapping area;

[0039] S53: Calculate the internal average radioactivity intensity value and average magnetic susceptibility value of each abnormal overlap area respectively, and judge whether the abnormal overlap area meets the target area screening conditions based on the preset numerical threshold standard, and then extract the heavy placer target area.

[0040] Optionally, the S53 specifically includes:

[0041] S531: Extract the radioactivity intensity values ​​of all grid cells in each abnormal overlap area and magnetic susceptibility values , a total of n valid pixels;

[0042] S532: Calculate the average radioactivity intensity value of the abnormal overlapping area and the average magnetic susceptibility value , the formula is: ; ;

[0043] S533: Call the regional background radioactivity average in S4 and the mean magnetic susceptibility , and set the corresponding screening threshold coefficients to 1.3 and 1.2 respectively to determine whether the following conditions are met:

[0044] Judgment condition 1, ;

[0045] Judgment condition 1, ;

[0046] If the above two judgment conditions are met at the same time, the corresponding abnormal overlap area will be marked as a heavy placer target area.

[0047] Optionally, the S6 specifically includes:

[0048] S61: extracting the spatial unit numbers of the selected heavy placer target areas, calculating the coordinates of the boundary center point of each target area unit, and recording the minimum circumscribed rectangular range covered by the target area;

[0049] S62: Extract the average radioactivity intensity value corresponding to the target unit from the layer attribute data and the average magnetic susceptibility value , and simultaneously record its generation time, coordinate reference system and anomaly level;

[0050] S63: All target area data are organized into standard structured report items. Each data item includes the target area number, center coordinates, spatial range, radioactivity intensity value, magnetic susceptibility intensity value, anomaly level, data collection time and processing batch number, and is uniformly output in GeoJSON format.

[0051] S64: Verify and sign the generated standardized report file for archiving.

[0052] Beneficial effects of the present invention:

[0053] The present invention integrates a gamma spectrum detection component and a magnetic susceptibility detection component into a ship-borne towed body, and combines water depth pressure compensation, attitude angle correction, and external magnetic disturbance suppression technology to achieve high-precision real-time acquisition and correction of gamma signals and magnetic susceptibility data. By performing continuous detection under high-stability attitude control near the bottom layer, physical response deviations caused by depth changes, equipment tilt, and environmental interference are effectively eliminated.

[0054] The present invention constructs radioactivity and magnetic susceptibility anomaly intensity maps and conducts spatial overlap analysis. It extracts heavy placer targets based on the overlapping areas of the two parameters, and establishes anomaly intensity classification criteria based on regional statistical means, thereby achieving rapid and quantitative judgment of high enrichment potential areas. Finally, the target area number, spatial location and physical parameters are output through a standardized structured report, providing clear data support for subsequent operation deployment. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0056] Figure 1 Schematic diagram of a method for rapid detection of seabed heavy sand deposits according to an embodiment of the present invention;

[0057] Figure 2 Schematic diagram of the data compensation and correction process according to an embodiment of the present invention. DETAILED DESCRIPTION

[0058] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. It is also noted that, to provide a more detailed description, the following embodiments are best and preferred embodiments, and those skilled in the art may employ alternative methods for implementing certain known technologies. Furthermore, the accompanying drawings are intended only to provide a more detailed description of the embodiments and are not intended to limit the present invention.

[0059] like Figure 1-Figure 2 As shown, the rapid detection method for seabed heavy sand deposits based on shipborne towed combined measurement includes the following steps:

[0060] S1: Connect the towed body, which integrates the gamma spectrum detection component, magnetic susceptibility detection component and pressure-bearing sealing structure, to the ship's integrated control host via a cable, and adjust the towed body to the preset seabed detection depth;

[0061] S2: Start the gamma spectrum detection component to obtain the total radioactive gamma channel count and uranium, thorium, and potassium content data in real time. At the same time, start the magnetic susceptibility detection component to obtain the sediment magnetic susceptibility and equipment inclination data in real time.

[0062] S3: Perform water depth pressure compensation correction on the gamma ray spectrum data obtained in S2, and perform inclination correction and external magnetic field interference shielding on the magnetic susceptibility data;

[0063] S4: Convert the corrected gamma spectrum data into a radioactivity anomaly intensity map, and convert the corrected magnetic susceptibility data into a magnetic susceptibility anomaly intensity map, both of which are marked with spatial coordinates at a scale of 1:10000;

[0064] S5: spatially superimpose the radioactivity anomaly intensity map and the magnetic susceptibility anomaly intensity map, extract the double-parameter anomaly overlap area, and screen out the heavy placer target area based on the preset threshold;

[0065] S6: Integrate the coordinates, radioactivity intensity and magnetic susceptibility intensity data of heavy placer targets into a standardized report.

[0066] S1 specifically includes:

[0067] S11: A high-modulus polyethylene cable with a preset strength of 20kN connects the towed vehicle, which includes the integrated gamma ray spectrometer detection component, magnetic susceptibility detection component, and pressure-sealed structure, to the shipboard integrated control host. Directional connectors and quick-lock connectors are installed at both ends of the cable to ensure the stability and reliability of power supply and data communication.

[0068] S12: The diving depth parameters are set on the onboard control host. The cable is released at a speed of 0.2 m / s through the automatic winch system. The current depth data of the towed body is monitored in real time through the pressure sensor and depth gauge integrated in the cable. The winch is automatically stopped when the towed body stably hovers at the preset detection layer 1.5 meters above the seabed.

[0069] S13: Synchronously start the hydrodynamic stabilization control unit through the control host. The hydrodynamic stabilization control unit includes a double-wing stabilization fin and a counterweight adjustment component located at the trailing edge of the towed body, which is used to keep the towed body's heading stable and the attitude angle less than 2°, ensuring the accuracy of detection data collection; the above steps use high-strength cables and quick connector structures to connect the towed body and the control host to ensure stable transmission of electrical signals in deep-sea environments; combined with the automatic winch and the real-time depth monitoring mechanism, precise control of the towed body's detection depth is achieved, and the towed body's attitude is maintained stable through stabilization fins and counterweight adjustment, effectively improving the measurement accuracy and operational safety of heavy sand mine detection near the bottom of the seabed.

[0070] S2 specifically includes:

[0071] S21: A startup command is issued via the shipboard integrated control host to the gamma spectrum detection component, which includes a highly sensitive sodium iodide (NaI) scintillation detector, a multi-channel analyzer (MCA), and a data transmission interface. After the detector is powered on and reaches an operating voltage of 750V, gamma spectrum data is collected within a 0.1-second interval. The multi-channel analyzer then analyzes the total channel count and the corresponding potassium, uranium, and thorium counts in the 1.46 MeV, 1.76 MeV, and 2.61 MeV energy regions.

[0072] S22: Synchronously activate the magnetic susceptibility detection component, which consists of a three-axis low-frequency inductive magnetic susceptibility sensor array and a three-dimensional accelerometer. After activation, it continuously collects changes in sediment response signals at a frequency of 1 Hz, and combines the three-axis attitude angle data measured by the three-dimensional accelerometer to output the volume magnetic susceptibility value and current equipment inclination data in real time;

[0073] S23: All collected data are transmitted back to the shipboard control host in real time through the data channel in the cable, and the gamma energy spectrum and magnetic susceptibility data streams are synchronously displayed in a time-stamped manner on the control interface for subsequent correction and processing. The above steps ensure the timely and high-precision acquisition of radioactive elements and magnetic characteristic data through the synchronous start-up and high-frequency acquisition of high-sensitivity gamma energy spectrum detection components and low-frequency three-axis magnetic susceptibility sensors, while integrating attitude angle calibration information to provide a complete original data basis for subsequent correction and anomaly identification, significantly improving the recognition accuracy of multi-parameter characteristics of heavy sand mines.

[0074] S3 specifically includes:

[0075] S31: matching the gamma spectrum data and radioactive element count data in each energy region collected by the gamma spectrum detection component with the water depth information acquired in real time by the pressure sensor integrated in the towed body, compensating for the counting deviation of the gamma signal caused by energy attenuation in the water body based on the hydrostatic pressure parameter corresponding to the water depth, and obtaining depth-corrected radioactive gamma spectrum data;

[0076] S32: combining the raw volume magnetic susceptibility data collected by the magnetic susceptibility detection component with the attitude angle data obtained by the triaxial accelerometer, and performing geometric attitude correction on the magnetic susceptibility value according to the current tilt angle of the device in the x-axis and y-axis directions to eliminate magnetic response distortion caused by the attitude deviation of the towed body;

[0077] S33: Call the sea area background magnetic field strength data recorded by the shipboard control host, perform interference judgment on the corrected magnetic susceptibility data, and filter out the data that exceeds the set magnetic field disturbance threshold range, thereby eliminating abnormal data points that may be disturbed by the external magnetic field, and retaining stable data for subsequent abnormality analysis; the above steps significantly improve the quantitative consistency of the gamma signal at different detection depths by introducing a water depth correction mechanism, and at the same time, through inclination compensation and background magnetic field interference shielding operations, significantly reduce the error of the magnetic susceptibility data caused by attitude deviation and environmental magnetic disturbance, effectively enhancing the reliability of the detection data and the accuracy of subsequent abnormality identification.

[0078] S31 specifically includes:

[0079] S311: The gamma spectrum detection component acquires the raw gamma spectrum data within each 0.1 second time window , and receives the water depth data h (in meters) of the towed body in real time. The water depth value is converted by the pressure sensor built into the pressure-bearing sealing structure; the water depth conversion formula is: , where h is the water depth (in meters); P is the hydrostatic pressure (in Pa), measured by the pressure sensor on the towed body; is the density of seawater, which is ; g is the acceleration due to gravity, and its value is ;

[0080] S312: Based on the hydrostatic pressure conditions corresponding to the water depth and the energy attenuation characteristics of the water body on gamma rays, the original gamma spectrum data is compensated. The formula is: ,in, is the corrected gamma spectrum data, Represents the exponential compensation factor of water body for signal attenuation, where is the average attenuation coefficient of water to gamma rays, which is 0.045;

[0081] S313: The uranium, thorium and potassium counts corresponding to all gamma-ray energy zones are corrected according to the same depth compensation, and the correction results are uniformly encoded and stored as a structured radioactivity spectrum data set for subsequent anomaly map generation and processing. By introducing water depth information into the gamma-ray signal compensation calculation, the signal attenuation effect caused by the absorption of high-energy particles by seawater is restored, which significantly improves the horizontal comparability of radioactivity data under different depth measurement conditions, and provides a reliable physical basis for the spatial anomaly identification of heavy placer targets.

[0082] S32 specifically includes:

[0083] S321: The three-axis accelerometer in the magnetic susceptibility detection component obtains the inclination angle data of the current towed body in the x-axis and y-axis directions in real time, which are recorded as and , in radians, represents the tilt offset relative to the vertical direction;

[0084] S322: Assume that the original volume susceptibility is , perform geometric posture correction on it, the specific formula is: ,in, is the corrected magnetic susceptibility, is the correction factor, which represents the projection ratio of the angle between the current attitude direction and the gravity direction;

[0085] S323: Increase the attitude angle by more than 0.35 radians (approx. ) is marked as an unstable state, and the data of the marked part is discarded to avoid the influence of attitude instability on the accuracy of magnetic susceptibility, and the remaining correction data is used for the subsequent generation of magnetic susceptibility anomaly map; the above steps correct the magnetic susceptibility measurement value based on the vector synthesis of the three-axis attitude angle, which can effectively offset the measurement error caused by the yaw and pitch of the towed body during the detection process, ensure the spatial consistency between the magnetic susceptibility anomaly characteristics and the real geological structure, and provide a high-confidence physical parameter basis for the identification of heavy placer targets.

[0086] S4 specifically includes:

[0087] S41: The corrected gamma spectrum data are normalized and interpolated according to the coordinates of the measuring point. The radioactivity intensity distribution field is generated in a uniform spatial grid with a scale of 1:10000 using the inverse distance weighted (IDW) algorithm. The mean value of the regional background is calculated. and standard deviation , set the gamma intensity value above The grid area is marked as the radioactive anomaly area, and the radioactive anomaly intensity map is output;

[0088] S42: The corrected magnetic susceptibility data are interpolated according to the spatial coordinates corresponding to the acquisition points, and the Kriging spatial interpolation algorithm is used to establish a continuous magnetic susceptibility distribution layer, and the background magnetic susceptibility mean is used as the basis for the interpolation of the magnetic susceptibility data. and standard deviation Set the abnormal judgment threshold, and set the magnetic susceptibility value higher than The grid area is marked as the magnetic susceptibility anomaly area, and the magnetic susceptibility anomaly intensity map is output;

[0089] S43: Encode the layer metadata of the two anomaly intensity maps separately, including sampling time, spatial reference system, interpolation algorithm and anomaly level description, and export them in vector format for use in the subsequent spatial overlay analysis process; the above steps construct gamma and magnetic susceptibility anomaly maps based on the spatial interpolation algorithm, which can effectively realize the spatial quantitative expression of radioactive and magnetic anomaly areas, significantly improving the accuracy and engineering practicality of target area identification in subsequent multi-parameter fusion analysis.

[0090] S5 specifically includes:

[0091] S51: Import the radioactivity anomaly intensity map and magnetic susceptibility anomaly intensity map generated by S4 into the geological information processing platform, and use the unified coordinate system (WGS84 / UTMZone50N) for reprojection and grid alignment to ensure that the two layers are completely matched in spatial dimensions;

[0092] S52: Use the layer overlay algorithm to perform pixel-level intersection operation on the two anomaly images and extract the anomaly images that meet the radioactivity intensity value at the same time. and magnetic susceptibility value The overlapping area is the abnormal overlapping area;

[0093] S53: Calculate the internal average radioactivity intensity value and average magnetic susceptibility value of each abnormal overlapping area respectively, and judge whether the abnormal overlapping area meets the target area screening conditions based on the preset numerical threshold standard, and then extract the heavy placer target area; the above steps realize the automatic extraction of dual-parameter significant abnormal areas through standardized spatial alignment and layer overlay, and complete the candidate area screening in combination with the mean judgment logic, which effectively improves the efficiency and accuracy of target area extraction and provides accurate support for the rapid identification of heavy placer targets.

[0094] S53 specifically includes:

[0095] S531: Extract the radioactivity intensity values ​​of all grid cells in each abnormal overlap area and magnetic susceptibility values , a total of n valid pixels;

[0096] S532: Calculate the average radioactivity intensity value of the abnormal overlapping area and the average magnetic susceptibility value , the formula is: ; ;

[0097] S533: Call the regional background radioactivity average in S4 and the mean magnetic susceptibility , and set the corresponding screening threshold coefficients to 1.3 and 1.2 respectively to determine whether the following conditions are met:

[0098] Judgment condition 1, ;

[0099] Judgment condition 1, ;

[0100] If the above two judgment conditions are met at the same time, the corresponding abnormal overlapping area will be marked as a heavy placer target area; the above steps can achieve high-precision screening of heavy placer targets while maintaining spatial resolution by averaging the multi-point data in the candidate area and comparing them with the set threshold standard, avoiding local extreme value interference and improving the stability and geological credibility of the identification results.

[0101] S6 specifically includes:

[0102] S61: extract the spatial unit numbers of the selected heavy placer target areas, calculate the coordinates of the boundary center point of each target area unit (expressed in latitude and longitude format), and record the minimum circumscribed rectangular range covered by the target area;

[0103] S62: Extract the average radioactivity intensity value corresponding to the target unit from the layer attribute data and the average magnetic susceptibility value , and simultaneously record its generation time, coordinate reference system (such as WGS 84) and anomaly level;

[0104] The classification rules for abnormal levels are as follows:

[0105] (1) Classification of abnormal radioactivity intensity:

[0106] Medium-level abnormality: ;

[0107] High-level anomalies: ;

[0108] Extremely high level anomaly: ;

[0109] (2) Classification of magnetic susceptibility anomaly levels:

[0110] Medium-level abnormality: ;

[0111] High-level anomalies: ;

[0112] Extremely high level anomaly: ;

[0113] Grade assessment principle: If the radioactivity and magnetic susceptibility levels are consistent, then this level is the final abnormality level of the target area; if the two levels are different, the lower level is the final assessment level to control the risk of misjudgment.

[0114] S63: All target area data are organized into standard structured report items. Each data item includes the target area number, center coordinates, spatial range, radioactivity intensity value, magnetic susceptibility intensity value, anomaly level, data collection time and processing batch number. The data is uniformly output in GeoJSON format and supports visual loading and remote platform call.

[0115] S64: Verify and sign the generated standardized report file to ensure data integrity and uniqueness. The above steps not only achieve a unified and standardized expression of heavy sand target area data by structuring and integrating spatial coordinates, physical anomaly indicators and metadata information into a standardized format report, but also provide a reliable data foundation and efficient system compatibility for subsequent remote analysis, targeted sampling and results archiving.

[0116] The present invention encompasses any alternatives, modifications, equivalents, and solutions that fall within the spirit and scope of the present invention. To provide a thorough understanding of the present invention, specific details are described in detail below in connection with the preferred embodiments of the present invention, but those skilled in the art will be able to fully understand the present invention without these detailed descriptions. Furthermore, to avoid unnecessary confusion regarding the essence of the present invention, well-known methods, processes, procedures, components, and circuits have not been described in detail.

[0117] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A rapid detection method for seabed heavy sand deposits based on shipborne towed combined measurement, characterized in that: The following steps are involved: S1: Connect the towed body, which integrates the gamma spectrum detection component, magnetic susceptibility detection component and pressure-bearing sealing structure, to the ship's integrated control host via a cable, and adjust the towed body to the preset seabed detection depth; S2: Start the gamma spectrum detection component to obtain the total radioactive gamma channel count and uranium, thorium, and potassium content data in real time. At the same time, start the magnetic susceptibility detection component to obtain the sediment magnetic susceptibility and equipment inclination data in real time. S3: Perform water depth pressure compensation correction on the gamma ray spectrum data obtained in S2, and perform inclination correction and external magnetic field interference shielding on the magnetic susceptibility data; The S3 specifically includes: S31: matching the gamma spectrum data and radioactive element count data in each energy region collected by the gamma spectrum detection component with the water depth information acquired in real time by the pressure sensor integrated in the towed body, compensating for the counting deviation of the gamma signal caused by energy attenuation in the water body based on the hydrostatic pressure parameter corresponding to the water depth, and obtaining depth-corrected radioactive gamma spectrum data; The S31 specifically includes: S311: The gamma spectrum detection component acquires the raw gamma spectrum data within each 0.1 second time window , and receive the water depth data h of the towed body in real time; S312: Based on the hydrostatic pressure conditions corresponding to the water depth and the energy attenuation characteristics of the water body on gamma rays, the original gamma spectrum data is compensated. The formula is: ,in, is the corrected gamma spectrum data, Represents the exponential compensation factor of water body for signal attenuation, where is the average attenuation coefficient of water to gamma rays, which is 0.045; S32: combining the raw volume magnetic susceptibility data collected by the magnetic susceptibility detection component with the three-axis attitude angle data obtained by the three-axis accelerometer, and performing geometric attitude correction on the magnetic susceptibility value according to the current tilt angle of the device in the x-axis and y-axis directions to eliminate magnetic response distortion caused by the attitude deviation of the towed body; S33: calling the sea area background magnetic field strength data recorded by the shipboard integrated control host, performing interference discrimination on the corrected magnetic susceptibility data, and filtering out data that exceeds the set magnetic field disturbance threshold range; S4: Convert the corrected gamma spectrum data into a radioactivity anomaly intensity map, and convert the corrected magnetic susceptibility data into a magnetic susceptibility anomaly intensity map, both of which are marked with spatial coordinates at a scale of 1:10000; S5: spatially superimpose the radioactivity anomaly intensity map and the magnetic susceptibility anomaly intensity map, extract the double-parameter anomaly overlap area, and screen out the heavy placer target area based on the preset threshold; S6: Integrate the coordinates, radioactivity intensity and magnetic susceptibility intensity data of heavy placer targets into a standardized report.

2. The method for rapid detection of seabed heavy sand deposits based on shipborne towed combined measurement according to claim 1 is characterized in that: Said S1 specifically includes: S11: The towed vehicle, which integrates the gamma spectrum detection component, magnetic susceptibility detection component, and pressure-sealed structure, is connected to the shipboard integrated control host via a high-modulus polyethylene cable with a preset strength of 20kN. A directional connector and a quick-locking plug-in are provided at each end of the cable. S12: The diving depth parameters are set on the ship's integrated control host. The cable is released at a speed of 0.2 m / s via the automatic winch system. The current depth data of the towed body is monitored in real time via the pressure sensor and depth gauge integrated in the cable. The winch is automatically stopped when the towed body stably hovers at the preset detection layer 1.5 meters above the seabed. S13: Synchronously start the hydrodynamic stabilization control unit through the shipboard integrated control host, wherein the hydrodynamic stabilization control unit includes a double-wing stabilization fin and a counterweight adjustment assembly located at the trailing edge of the towed body, and is used to keep the towed body's heading stable and its attitude angle less than 2°.

3. The method for rapid detection of seabed heavy sand deposits based on shipborne towed combined measurement according to claim 1 is characterized in that: The S2 specifically includes: S21: A start-up command is issued to the gamma spectrum detection component via the shipboard integrated control host. The gamma spectrum detection component includes a sodium iodide scintillation detector, a multi-channel analyzer, and a data transmission interface. After the sodium iodide scintillation detector is powered on and reaches an operating voltage of 750V, gamma spectrum data is collected within a 0.1 second time interval. The multi-channel analyzer then analyzes the total channel count and the potassium, uranium, and thorium count values ​​corresponding to the energy regions of 1.46 MeV, 1.76 MeV, and 2.61 MeV. S22: Synchronously activate the magnetic susceptibility detection component, which is composed of a three-axis low-frequency inductive magnetic susceptibility sensor array and a three-axis accelerometer. After activation, the component continuously collects changes in sediment response signals at a frequency of 1 Hz, and combines the three-axis attitude angle data measured by the three-axis accelerometer to output the volume magnetic susceptibility value and the current device inclination angle data in real time; S23: All collected data are transmitted back to the shipboard integrated control host in real time through the cable data channel, and the gamma energy spectrum and magnetic susceptibility data streams are synchronously displayed on the control interface in a time-stamped manner.

4. The method for rapid detection of seabed heavy sand mines based on shipborne towed combined measurement according to claim 1 is characterized in that: The S32 specifically includes: S321: The three-axis accelerometer in the magnetic susceptibility detection component obtains the inclination angle data of the current towed body in the x-axis and y-axis directions in real time, which are recorded as and , in radians; S322: Assume that the original volume susceptibility is , perform geometric posture correction on it, the specific formula is: ,in, is the corrected magnetic susceptibility, is the correction factor, which represents the projection ratio of the angle between the current attitude direction and the gravity direction; S323: Mark the sampled data with a posture angle exceeding 0.35 radians as an unstable state, and remove the data of the marked portion.

5. The method for rapid detection of seabed heavy sand mines based on shipborne towed combined measurement according to claim 1 is characterized in that: The S4 specifically includes: S41: The corrected gamma spectrum data are normalized and interpolated according to the coordinates of the measuring point position, and the radioactivity intensity distribution field is generated in a unified spatial grid with a scale of 1:10000 using the inverse distance weighted algorithm; and the radioactivity intensity distribution field is generated based on the regional background radioactivity mean. and standard deviation , set the gamma intensity value above The grid area is marked as the radioactive anomaly area, and the radioactive anomaly intensity map is output; S42: The corrected magnetic susceptibility data are interpolated according to the spatial coordinates corresponding to the acquisition points, and the Kriging spatial interpolation algorithm is used to establish a continuous magnetic susceptibility distribution layer, and the background magnetic susceptibility mean is used to calculate the magnetic susceptibility distribution layer. and standard deviation Set the abnormal judgment threshold, and set the magnetic susceptibility value higher than The grid area is marked as the magnetic susceptibility anomaly area, and the magnetic susceptibility anomaly intensity map is output; S43: Encode the layer metadata of the two anomaly intensity maps, including sampling time, spatial reference system, interpolation algorithm and anomaly level description, and export them in vector format.

6. The method for rapid detection of seabed heavy sand deposits based on shipborne towed combined measurement according to claim 5 is characterized in that: The S5 specifically includes: S51: Import the radioactivity anomaly intensity map and magnetic susceptibility anomaly intensity map generated by S4 into the geological information processing platform, use a unified coordinate system for reprojection and grid alignment, and ensure that the two layers are completely matched in spatial dimensions; S52: Use the layer overlay algorithm to perform pixel-level intersection operation on the two anomaly images and extract the anomaly images that meet the radioactivity intensity value at the same time. and magnetic susceptibility value The overlapping area is the abnormal overlapping area; S53: Calculate the internal average radioactivity intensity value and average magnetic susceptibility value of each abnormal overlap area respectively, and judge whether the abnormal overlap area meets the target area screening conditions based on the preset numerical threshold standard, and then extract the heavy placer target area.

7. The method for rapid detection of seabed heavy sand deposits based on shipborne towed combined measurement according to claim 6 is characterized in that: The S53 specifically includes: S531: Extract the radioactivity intensity values ​​of all grid cells in each abnormal overlap area and magnetic susceptibility values , a total of n valid pixels; S532: Calculate the average radioactivity intensity value of the abnormal overlapping area and the average magnetic susceptibility value , the formula is: ; ; S533: Call the regional background radioactivity average in S4 and the mean magnetic susceptibility , and set the corresponding screening threshold coefficients to 1.3 and 1.2 respectively to determine whether the following conditions are met: Judgment condition 1, ; Judgment condition 2, ; If the above two judgment conditions are met at the same time, the corresponding abnormal overlap area will be marked as a heavy placer target area.

8. The method for rapid detection of seabed heavy sand deposits based on shipborne towed combined measurement according to claim 7 is characterized in that: The S6 specifically includes: S61: extracting the spatial unit numbers of the selected heavy placer target areas, calculating the coordinates of the boundary center point of each target area unit, and recording the minimum circumscribed rectangular range covered by the target area; S62: Extract the average radioactivity intensity value corresponding to the target unit from the layer attribute data and the average magnetic susceptibility value , and simultaneously record its generation time, coordinate reference system and anomaly level; S63: All target area data are organized into standard structured report items. Each data item includes the target area number, center coordinates, spatial range, radioactivity intensity value, magnetic susceptibility intensity value, anomaly level, data collection time and processing batch number, and is uniformly output in GeoJSON format. S64: Verify and sign the generated standardized report file for archiving.

Images