A method for estimating the gamma value of seawater radionuclides

Abstract

The present invention discloses a method for estimating the gamma value of radionuclides in seawater. The radionuclides in seawater are detected by a buoy during the seawater drifting process to generate sampling data, and the sampling data includes the sampling time, longitude and latitude values of the sampling point, and the gamma value of the radionuclides in seawater. Wherein, the gamma value estimation method includes: finding the sampling points with missing gamma values in the sampling data as the estimation points; extracting M sampling points with real gamma values before and after the estimation point in terms of sampling time; using the longitude and latitude values of the estimation point and the 2M sampling points to calculate the distance between each sampling point and the estimation point; assigning weights to the 2M sampling points according to the 2M distances; calculating the sum of the products of the gamma values of the 2M sampling points and their weights as the gamma value of the estimation point A0. The present invention can quickly fit and estimate the gamma value at the missing position according to the drifting law of the buoy and the gamma values of the surrounding points to form complete gamma data.

Description

Technical Field

[0001] The invention belongs to the technical field of marine environment monitoring, and in particular, relates to a method for processing gamma data collected by a marine radioactive drifting buoy. Background Art

[0002] The marine radioactive drifting buoy is a device used to monitor radioactive nuclides in seawater. In actual use, the marine radioactive drifting buoy is usually deployed in the open sea to monitor the longitude and latitude of each drifting point and the gamma value of the radioactive nuclides contained in the seawater at that location in real time. The gamma value collected by the marine radioactive drifting buoy is generally sent to the monitoring center on the shore by satellite communication, so that the shore workers can remotely monitor and warn the distribution of radioactive nuclides in seawater.

[0003] Since the marine environment is complex and changeable and there are many interference factors, the marine radioactive drifting buoy is greatly affected by the sea conditions during the collection of gamma data. Changes in the marine environment interfere with the measurement of gamma values. The phenomenon is that the gamma value may not be detected at a certain sampling point, resulting in incomplete data collection, which will affect the overall analysis and prediction of the distribution of radioactive nuclides in seawater by operators.

[0004] In view of this, how to combine the changing patterns of seawater radionuclide gamma data to predict and estimate the lost gamma data in order to obtain complete seawater radionuclide gamma data is an important topic in the current development of domestic marine radioactivity measurement. Summary of the invention

[0005] The purpose of the present invention is to provide a method for estimating the gamma value of seawater radioactive nuclides, which can quickly fit and estimate the gamma value of the missing position according to the drift law of the ocean radioactive drifting buoy and the gamma values ​​of the surrounding points, so as to provide complete seawater radioactive nuclide gamma data for operators.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions to achieve the above problems:

[0007] A method for estimating the gamma value of seawater radionuclides, wherein the seawater radionuclides are detected by a buoy during drifting in seawater and sampling data is generated, wherein the sampling data includes the sampling time, longitude and latitude values ​​of the sampling point and the gamma value of the seawater radionuclides; wherein the gamma value estimation method comprises:

[0008] Find the sampling point where the gamma value is lost in the sampled data as the estimated point A 0 ;

[0009] Extract the sampling time at the estimated point A 0The M sampling points before and after that have real gamma values ​​are denoted as A 1 , A 2 ,……,A 2M ;

[0010] Using the estimated point A 0 and 2M sampling points A 1 , A 2 ,……,A 2M The latitude and longitude values ​​are calculated, and the distance between each sampling point and the estimated point is recorded as d 1 d 2 ,……,d 2M ;

[0011] According to 2M distances d 1 d 2 ,……,d 2M Assigning weights to the 2M sampling points;

[0012] Calculate the 2M sampling points A 1 , A 2 ,……,A 2M The sum of the gamma value and its weight is used as the estimated point A 0 The gamma value of .

[0013] In some embodiments of the present application, in order to improve the accuracy of gamma value estimation, the 2M sampling points A are selected. 1 , A 2 ,……,A 2M Among the sampling points with true gamma values, the sampling time is far from the estimated point A 0 The sampling time of the 2M sampling points most recent.

[0014] In some embodiments of the present application, the value of M may be 2 or 3, which can shorten the calculation time and improve the prediction efficiency while ensuring that the gamma value estimation result is as accurate as possible.

[0015] In some embodiments of the present application, when calculating the distance between each of the sampling points and the estimated point, the longitude and latitude values ​​of each of the sampling points and the longitude and latitude values ​​of the estimated point may be substituted into the following distance calculation formula to obtain:

[0016] d i =R*arccos[cos(Y1)*cos(Y2)*cos(X1-X2)+sin(Y1)*sin(Y2)]*π / 180;

[0017] Among them, d i Indicates sampling point A i With estimated point A 0The distance between them; R is the radius of the earth; (X1, Y1) is the sampling point A i The longitude and latitude values ​​of the estimated point A. 0 The longitude and latitude values ​​of .

[0018] In some embodiments of the present application, when weights are assigned to the 2M sampling points, the weights of the 2M sampling points are negatively correlated with the 2M distances.

[0019] In some embodiments of the present application, the weight allocation process of the 2M sampling points may include:

[0020] Calculate the reciprocal sum of 2M distances:

[0021] Calculate sampling point A i Weight:

[0022] Compared with the prior art, the advantages and positive effects of the present invention are: the gamma value estimation method of seawater radioactive nuclides of the present invention is not limited by the location of the drifting buoy, nor is it affected by the interference of the marine environment. It can quickly estimate the gamma value of the location of the marine radioactive drifting buoy, solves the problem of occasional missing data of the drifting buoy, and provides complete gamma data for the overall analysis and prediction of the distribution of seawater radioactive nuclides by operating personnel.

[0023] Other features and advantages of the present invention will become more apparent after reading the detailed description of the embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 It is an overall architecture diagram of an embodiment of a marine monitoring system;

[0026] Figure 2 It is an overall flow chart of an embodiment of the method for estimating the gamma value of seawater radionuclides proposed by the present invention. DETAILED DESCRIPTION

[0027] The specific implementation modes of the present invention are described in detail below with reference to the accompanying drawings.

[0028] The gamma value estimation method of this embodiment is designed for the sampling data collected by the marine radioactive drifting buoy. Combining the drifting law of the marine radioactive drifting buoy and the gamma values ​​of the surrounding points, the gamma value fitting estimation is performed for the sampling points where the gamma data is lost, thereby forming complete gamma data to make up for the defect that the marine radioactive drifting buoy occasionally fails to detect gamma data due to interference from the complex marine environment.

[0029] After being deployed in the open sea, the marine radioactive drifting buoy drifts with the current, uses the satellite system to locate, and regularly collects radioactive nuclides in the seawater, generates sampling data and sends it to the monitoring center on the shore through the satellite system. Figure 1 As shown, it can be provided to shoreside operators to complete the remote monitoring task of the marine environment.

[0030] The ocean radioactive drifting buoy of this embodiment generates sampling data which includes at least the sampling time of each sampling point; the physical position of the buoy drifting point at the sampling time, i.e., the longitude and latitude values; and the gamma value of the radioactive nuclides in the seawater at the drifting point.

[0031] The ocean radioactive drifting buoy sends sampling data to the monitoring center regularly. After receiving the sampling data, if the monitoring center finds that some sampling points in the sampling data have missing gamma values, the gamma value estimation method of this embodiment can be used to quickly fit the gamma values ​​of the missing positions.

[0032] Combination Figure 2 As shown, the gamma value estimation method of seawater radionuclides in this embodiment mainly includes the following processes:

[0033] S101, find the sampling point where the gamma value is lost in the sampled data as the estimated point A 0 .

[0034] In this embodiment, the gamma values ​​of all sampling points in the sampled data can be traversed to find the sampling points with missing gamma values, and the sampling points are recorded as estimated points A. 0 , in order to distinguish it from other sampling points.

[0035] S102, extract sampling time at estimated point A 0 The M sampling points before and after that have real gamma values ​​are denoted as A 1 , A 2 ,……,A 2M .

[0036] The gamma value estimation method of this embodiment is based on the estimation point A 0 The gamma value of the surrounding sampling points is fitted and estimated. Therefore, it is necessary to retrieve the sampling time at the estimated point A. 0Multiple sampling points before and after the real gamma value participate in the subsequent calculation.

[0037] As a preferred embodiment, in order to improve the accuracy of the estimation result, it is best to select the sampling time closest to the estimation point A. 0 That is, according to the order of sampling time, select the estimated point A 0 The previous M sampling points with true gamma values, and the estimated point A 0 The next M sampling points have real gamma values, and these 2M sampling points can be recorded as A 1 , A 2 ,……,A 2M .

[0038] In some embodiments, M=2 or M=3 is preferably configured. That is, the estimated points A are extracted in time order. 0 2 or 3 sampling points with real gamma values ​​before and after are used to estimate point A 0 The gamma value of is estimated by fitting.

[0039] S103: Calculate the distance between each sampling point and the estimated point.

[0040] In this embodiment, the estimated point A can be used 0 The distance between two points is calculated using the latitude and longitude values ​​of the sampling point.

[0041] Specifically, if the longitude and latitude values ​​of two sampling points on the earth are known, the distance between the two sampling points can be calculated by substituting them into the following distance calculation formula:

[0042] d i =R*arccos[cos(Y1)*cos(Y2)*cos(X1-X2)+sin(Y1)*sin(Y2)]*π / 180.

[0043] In the above formula, (X1, Y1) can be substituted into one of the sampling points A i The longitude and latitude values ​​of the estimated point A. 0 The longitude and latitude values; R is the radius of the earth, which can be taken as R = 6371km; π is taken as 3.1415926, and the d calculated from this i Sampling point A i With estimated point A 0 Here, d i The units are the same as the units of the Earth's radius R.

[0044] Substitute the longitude and latitude values ​​of the extracted 2M sampling points into the above distance calculation formula to calculate the distance between each sampling point and the estimated point A.0 The distance between them can be denoted as d 1 d 2 ,……,d 2M .

[0045] S104. Allocate weights to the 2M sampling points.

[0046] In this embodiment, the 2M sampling points and the estimated point A can be used to 0 The distance between them is used to reasonably assign weight values ​​to each sampling point.

[0047] Since the distribution of radionuclides in seawater is continuous, the distance estimation point A 0 The closer the sampling point, the closer the gamma value is to the estimated point A. 0 In view of this, this embodiment uses 2M sampling points and estimation point A 0 Based on the distance between, the distance estimation point A 0 The weight coefficient assigned to the distant sampling point is small, and the distance to the estimated point A 0 The weight coefficient assigned to the closest sampling point is large, that is, the weight of the 2M sampling points is equal to the calculated 2M distances d 1 d 2 ,……,d 2M There is a negative correlation between them, thus achieving a reasonable distribution of weight coefficients.

[0048] Specifically, we can first calculate 2M distances d 1 d 2 ,……,d 2M The reciprocal sum of , that is:

[0049]

[0050] Then, each sampling point is compared with the estimated point A 0 The reciprocal of the distance between divided by the reciprocal sum Sum, get the weight assigned to the sampling point. That is:

[0051]

[0052] Among them, W i is sampling point A i The assigned weights are i=1, 2, ..., 2M.

[0053] S105, according to 2M sampling points A 1 , A 2 ,……,A 2M The gamma value component is calculated based on the gamma value of and the weight assigned to it.

[0054] In this embodiment, the gamma value of each sampling point can be multiplied by its assigned weight to obtain the gamma value component corresponding to the sampling point. That is:

[0055] G i =W i ×g i ;

[0056] Among them, g i Sampling point A i The gamma value is the real value, that is, the gamma value actually collected by the ocean radioactive drifting buoy; G i Sampling point A i The corresponding gamma value components. Thus, 2M gamma value components can be calculated.

[0057] S106, taking the sum of 2M gamma value components as the estimated point A 0 The gamma value of .

[0058] In this embodiment, the estimated point A can be obtained by adding 2M gamma value components. 0 The gamma value of . That is:

[0059]

[0060] Where G is the estimated point A 0 The gamma value of .

[0061] At this point, the gamma value estimation process of seawater radionuclides is completed.

[0062] For example:

[0063] Assume that a set of sampling data collected by an ocean radioactive drifting buoy is as follows:

[0064] A 1 :2019-7-10 12:0 Longitude:119.831474 Latitude:35.616001 g 1 =0.05;

[0065] A 2 :2019-7-10 12:2 Longitude:119.831383 Latitude:35.616215 g 2 =0.063996;

[0066] A 0 :2019-7-10 12:4 Longitude: 119.831314 Latitude: 35.616364

[0067] A 3:2019-7-10 12:6 Longitude:119.831245 Latitude:35.616520 g 3 =0.063996;

[0068] A 4 :2019-7-10 12:9 Longitude:119.831108 Latitude:35.616776 g 4 =0.066568.

[0069] From the above sampling data, it can be seen that sampling point A 0 The gamma value of the sampling point A is lost. 0 As the estimation point, according to the order of sampling time, from the estimation point A 0 Select two sampling points A with real gamma values ​​forward 1 , A 2 , and then select two sampling points A with real gamma values 3 , A 4 , used to estimate point A 0 Gamma value of the fit is estimated.

[0070] The four sampling points A 1 , A 2 , A 3 , A 4 The latitude and longitude values ​​and estimated point A 0 Substitute the longitude and latitude values ​​into the distance calculation formula to calculate the distance from each sampling point to the estimated point. That is:

[0071] d 1 =6371*arccos[cos(35.616001)*cos(35.616364)*cos(119.831474-119.831314)+sin(35.616001)*sin(35.616364)*3.1415926 / 180=0.042881km=42.881m;

[0072] d 2 =6371*arccos[cos(35.616215)*cos(35.616364)*cos(119.831383-119.831314)+sin(35.616215)*sin(35.616364)*3.1415926 / 180=0.017703km=17.703m;

[0073] d 3=6371*arccos[cos(35.616520)*cos(35.616364)*cos(119.831245-119.831314)+sin(35.616520)*sin(35.616364)*3.1415926 / 180=0.018434km=18.434m;

[0074] d 4 =6371*arccos[cos(35.616776)*cos(35.616364)*cos(119.831108-119.831314)+sin(35.616776)*sin(35.616364)*3.1415926 / 180=0.049477km=49.477m.

[0075] Calculate the reciprocal sum of the four distances, namely:

[0076]

[0077] Calculate four sampling points A 1 , A 2 , A 3 , A 4 The weights assigned are:

[0078]

[0079]

[0080]

[0081]

[0082] Calculate four sampling points A 1 , A 2 , A 3 , A 4 The corresponding gamma value component. That is:

[0083] G 1 =W 1 ×g 1 =15%×0.05=0.0075;

[0084] G 12 =W 2 ×g 2 =37%×0.063996=0.02367852;

[0085] G 3 =W 3 ×g 3=35%×0.063996=0.0223986;

[0086] G 4 =W 4 ×g 4 =13%×0.066568=0.00865384.

[0087] Calculate the estimated point A 0 The gamma value is:

[0088] G=G 1 +G 2 +G 3 +G 4 =0.0075+0.02367852+0.0223986+0.00865384=0.06223096.

[0089] The calculated gamma value G is used as the radionuclide gamma value of seawater at the longitude 119.831314 and latitude 35.616364 to complete the gamma value estimation process.

[0090] Of course, 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 principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for estimating the gamma value of seawater radionuclides, wherein the seawater radionuclides are detected by a buoy during drifting in seawater and sampling data are generated, wherein the sampling data includes the sampling time, longitude and latitude values ​​of the sampling point and the gamma value of the seawater radionuclides; characterized in that: The gamma value estimation method comprises: Find the sampling point where the gamma value is lost in the sampled data as the estimated point A0; Extract the M sampling points with real gamma values ​​before and after the estimated point, and record them as A1, A2, ..., A 2M ; Using the estimated point A0 and 2M sampling points A1, A2, ..., A 2M The latitude and longitude values ​​of the sampling points are calculated, and the distance between each sampling point and the estimated point is recorded as d1, d2, ..., d 2M ; According to 2M distances d1, d2, ..., d 2M Allocate weights to the 2M sampling points; wherein the weight allocation process of the 2M sampling points includes: Calculate the reciprocal sum of 2M distances: Calculate sampling point A i Weight: i=1,2,……,2M; Calculate the 2M sampling points A1, A2, ..., A 2M The sum of the gamma value of the estimated point A0 and the product of its weight is taken as the gamma value of the estimated point A0.

2. The method for estimating the gamma value of seawater radionuclides according to claim 1, characterized in that: The 2M sampling points A1, A2, ..., A 2M These are the 2M sampling points whose sampling times are closest to the sampling time of the estimated point A0 among the sampling points with true gamma values.

3. The method for estimating the gamma value of seawater radionuclides according to claim 1, characterized in that: The value of M is 2 or 3.

4. The method for estimating the gamma value of seawater radionuclides according to claim 1, characterized in that: When calculating the distance between each of the sampling points and the estimated point, the longitude and latitude values ​​of each of the sampling points and the longitude and latitude values ​​of the estimated point are respectively substituted into the following distance calculation formula to obtain: d i =R*arccos[cos(Y1)*cos(Y2)*cos(X1-X2)+sin(Y1)*sin(Y2)]*π / 180; Among them, d i Indicates sampling point A i The distance from the estimated point A0; R is the radius of the earth; (X1, Y1) is the sampling point A i (X2, Y2) are the longitude and latitude values ​​of the estimated point A0.

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