Data correction method of rain gauge

Abstract

The invention discloses a data correction method for a rain gauge. The method comprises the following steps: S1, calculating analog data; s2, measuring the average bucket number; s3, calculating a correction coefficient and tipping bucket simulation time; s4, calculating a rain intensity interval coefficient; and S5, correcting the measured value of the tipping bucket rain gauge. According to the method, errors under different rain intensities can be corrected to be within the error range specified by the national standard, so that the measurement accuracy of the tipping-bucket rain gauge is improved. According to the method, the rainfall intensity can be judged according to the overturning time and the overturning times of the rain hopper, data measured by the rain gauge are corrected, and it is guaranteed that the error is within a reasonable range. And the measured data is closer to the actual rainfall.

Description

Technical Field

[0001] The invention relates to the field of rain gauges, and in particular to a data correction method for a rain gauge. Background Art

[0002] The structure of the single-layer tipping bucket rain gauge currently available on the market is as follows: Figure 1 As shown in the figure, there is a problem of excessive detection error in heavy rainfall, which originates from the design of the tipping bucket rain gauge. When the rainfall intensity gradually increases, the amount of rain passing through the rain collecting funnel also increases, and the error caused by the rain bucket turning over will also increase, resulting in the error of the tipping bucket rain gauge in actual use deviating from the design expectation.

[0003] In addition, the accuracy level of the rain gauge specified by the national standard is divided into three levels, the third level accuracy is ≤±4%, the second level accuracy is ≤±3%, and the first level accuracy is ≤±2%. The existing tipping bucket rain gauge calibration method only calibrates the measurement results to the third level standard specified by the national standard, that is, within the error range of ±4% when the rainfall intensity is 0mm / min-4mm / min. However, as the rainfall intensity continues to increase, the error of the rain gauge will be greater than ±4%, resulting in a large deviation between the measured rainfall and the actual rainfall. If you want to increase its accuracy, you need to increase the internal structure, such as adding a double-layer tipping bucket structure, and it takes a lot of manpower and time to calibrate the rain gauge, which greatly increases the cost of the rain gauge.

[0004] Therefore, there is an urgent need for an algorithm that can accurately correct the measurement results of the tipping bucket rain gauge. Summary of the invention

[0005] In order to solve the problem in the background technology, the present invention provides a data correction method for a rain gauge, which can correct the error range to the first-level standard specified by the national standard, that is, the error range of ±2% when the rainfall intensity is 0mm / min-4mm / min, and can also correct the measurement result to the error range specified by the national standard when the rainfall intensity is greater than 4mm / min.

[0006] To this end, the present invention adopts the following technical solutions:

[0007] A data correction method for a rain gauge comprises the following steps:

[0008] S1, calculation of simulation data:

[0009] Using the caliber and resolution of the rain gauge to be corrected, at different rainfall intensities RZ i The standard bucket number N and different rainfall times S are calculated by simulating rainfall P. i ;

[0010] Among them, RZ i+1 -RZi =n, n is the interval between two consecutive rainfall intensities; i is the rainfall intensity number, i∈[1,I], I is the maximum value of the rainfall intensity number;

[0011] S2, measure the average number of buckets:

[0012] Under laboratory conditions, simulated rainfall P was used to experimentally obtain different rainfall intensities RZ i After multiple experiments, the number of measurements under each different rainfall intensity RZ i The average number of buckets measured under the laboratory is obtained by taking the average number of buckets N i ;

[0013] S3, calculate the correction factor and dump simulation time

[0014] S31, calculate the correction factor Y by the following formula i :

[0015]

[0016] S32, calculate the dumping simulation time T by the following formula i :

[0017]

[0018] S4, calculate the rainfall intensity interval coefficient K i :

[0019] K i =|(Y i+1 -Y i ) / (T i+1 -T i )|;i∈[i,I-1];

[0020] S5, correcting the measured value of the tipping bucket rain gauge, including the following steps:

[0021] S51, obtaining the actual time T of the dump bucket during actual use c and the actual number of buckets N c ;

[0022] S52, firstly, the actual time T of the dump bucket is c Compare with the dumping simulation time obtained in S32 until T x+1 <T c ≤T x When the value of x is obtained, x is the actual rainfall intensity number; among them, the actual time of tipping bucket T c T is the time interval between two consecutive flips of the rain gauge to be corrected. x ∈[T1,T I-1 ],x∈[1,I-1];

[0023] Then calculate the corrected number of buckets N by the following formula: x And output:

[0024] N x =N c ·[Y x +K x (|T c -T x |)];

[0025] Among them, Y x ∈[Y1,Y I-1 ]; K x ∈[K1,K I-1 ].

[0026] Preferably, 0.1≤n≤4 in S1.

[0027] The standard bucket number N in S1 is calculated by the following formula:

[0028] Simulated rainfall P÷resolution=standard bucket number N;

[0029] The rainfall time S in S1 i Calculated by the following formula:

[0030] Simulated rainfall P ÷ rainfall intensity RZ i = Rainfall time S i .

[0031] Preferably, the rain gauge to be corrected in S1 is a tipping bucket rain gauge.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The method of the present invention can judge the rainfall intensity according to the tipping bucket turning time and the turning times of the rain bucket, and correct the data measured by the rain gauge. Under a relatively large rainfall intensity, the error can be ensured to be within the error range specified by the national standard, thereby improving the measurement accuracy of the tipping bucket rain gauge. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the internal structure of an existing single tipping bucket rain gauge;

[0035] Figure 2 The figure is a flow chart of the data correction method of the present invention. DETAILED DESCRIPTION

[0036] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0037] See also Figure 2 The data correction method of the rain gauge of the present invention comprises the following steps:

[0038] S1, calculation of simulation data:

[0039] Using the caliber and resolution of the tipping bucket rain gauge to be corrected, the different rainfall intensities RZ are calculated by simulating the rainfall P i Standard bucket number N and rainfall time S i Among them, the rainfall intensity RZ i The minimum value of RZ is 1mm / min. i+1 -RZ i =0.5mm / min; i is the rainfall intensity number, i∈[1,I], I is the maximum value of the rainfall intensity number;

[0040] The standard bucket number N and rainfall time S i Calculated by the following two formulas:

[0041] Simulated rainfall P÷resolution=standard bucket number N;

[0042] Simulated rainfall P ÷ rainfall intensity RZi = rainfall time S i .

[0043] In one embodiment of the present invention, a rain gauge with a caliber of 159 mm and a resolution of 0.2 mm is used. When the simulated rainfall is 30 mm, the standard number of buckets of the rain gauge is calculated to be 150 buckets. The rainfall time calculated under different rainfall intensities is shown in Table 1.

[0044] S2, measure the average number of buckets:

[0045] Under laboratory conditions, simulated rainfall P was used to experimentally obtain different rainfall intensities RZ i After multiple experiments, the number of measurements under each different rainfall intensity RZ i Take the average of the measured bucket numbers under the laboratory measurement to get the average bucket number N i The more times the experiment is conducted, the closer the obtained data is to the real data.

[0046] Taking the rain gauge used in S1 as an example, the average bucket count measured in the laboratory is shown in Table 1:

[0047] Table 1

[0048] Simulated rainfall P (mm) 30 Resolution mm 0.2 Standard number of buckets 150 Rainfall intensity (mm / min) 1 1.5 2 2.5 3 3.5 4 4.5 5 6 7 8 Rainfall time 1800 1200 900 720 600 514 450 400 360 300 257 225 Average number of fights 152 150.7 149 145 141.2 139.2 137.6 134.6 133.5 131.5 129.7 128.5

[0049] Among them, the interval between rainfall intensity of 5 mm / min and 8 mm / min is 1.

[0050] S3, calculating the correction coefficient and the dumping simulation time, includes the following steps:

[0051] S31, calculate the correction factor Y by the following formula i :

[0052]

[0053] S32, calculate the time interval between two consecutive overturns of the rain gauge under different rainfall intensities, i.e., the overturn simulation time T i :

[0054]

[0055] The corresponding relationship between rainfall intensity, correction coefficient and dumping simulation time is obtained through the data obtained from S1 and S2, as shown in Table 2:

[0056] Table 2

[0057] Rainfall intensity number i 1 2 3 4 5 6 7 8 9 10 11 12 Rain intensity mm / min 1 1.5 2 2.5 3 3.5 4 4.5 5 6 7 8 Correction factor 0.987 0.995 1.007 1.034 1.062 1.078 1.090 1.114 1.124 1.141 1.157 1.167 Dump simulation time 11.84 7.96 6.04 4.97 4.25 3.69 3.27 2.97 2.70 2.28 1.98 1.75

[0058] S4, calculate the rainfall intensity interval coefficient K i :

[0059] The correction factor Y calculated by S3 i and dumping simulation time T i Composition coordinate point (T i , Y i ), draw the coordinate point (T i , Y i ) and then compare it with (T i+1 , Y i+1 ) and calculate its slope, which is K i The calculation formula is as follows:

[0060] K i =|(Y i+1 -Y i ) / (T i+1 -T i )|;i∈[1,I-1].

[0061] In the above embodiment, the rainfall intensity interval coefficient K i The relationship with the corresponding rainfall intensity interval is shown in Table 3:

[0062] Table 3

[0063] Corresponding rainfall intensity range 1-1.5 1.5-2 2-2.5 2.5-3 3-3.5 3.5-4 Correction coefficient range [0.987,0.995) [0.995，1.007) [1.007，1.034) [1.034,1.062) [1.062，1.078) [1.078，1.090) Tipping simulation time interval (7.96，11.84] (6.04，7.96] (4.97，6.04] (4.25，4.97] (3.69，4.25] (3.27，3.69] Rainfall intensity interval coefficient 0.0022 0.0059 0.0258 0.0389 0.0275 0.0295 Corresponding rainfall intensity range 4-4.5 4.5-5 5-6 6-7 7-8 Correction coefficient range [1.090，1.114) [1.114,1.124) [1.124,1.141) [1.141，1.157) [1.157，1.167] Tipping simulation time interval (2.97，3.27] (2.70，2.97] (2.28，2.70] (1.98，2.28] [1.75，1.98] Rainfall intensity interval coefficient 0.0814 0.0334 0.0412 0.0530 0.0466

[0064] S5, correcting the measured value of the tipping bucket rain gauge, including the following steps:

[0065] S51, measure the actual tipping time T during rainfall c and the actual number of buckets N c ;

[0066] S52, the actual time of dumping the bucket T cCompare with the dump simulation time and check T c The dumping simulation time interval T x ~T x+1 , x∈[1,I-1]; that is, T x+1 <T c ≤T x , x is the actual rainfall intensity number; because the tipping bucket simulation time will gradually decrease with the increase of rainfall intensity, so T x+1 <T x ; Determine the correction coefficient interval Y according to the value of x x ~Y x+1 and rainfall intensity interval coefficient K x ; Calculate the corrected number of buckets N by the following formula x And output:

[0067] N x =N c ·[Y x +K x (|T c -T x |)].

[0068] Among them, the actual time of dumping is T c Y is the time interval between two consecutive flips of the rain gauge. x ∈[Y1,Y I-1 ]; K x ∈[K1,K I-1 ].

[0069] In the above embodiment, two sets of data are measured, wherein: the first set of data is measured under a rain intensity of RZ = 1 mm / min, T c =11.82, N c =152; The second set of data is measured under the rain intensity of RZ = 7mm / min, T c =2.0,N c =128.

[0070] The first group of T c It falls within the bucket tipping simulation time interval of 11.84 to 7.96, at which time x is 1, and the corresponding rainfall intensity interval coefficient K1 is 0.0022, then the corrected bucket number N1 = 150, which is the same as the standard value and has no error.

[0071] The second group of T c It falls within the bucket tipping simulation time interval of 2.28 to 1.98. At this time, x is 6, and the corresponding rain intensity interval coefficient K6 is 0.0530. Then the corrected bucket number N6 = 147.9, and the corrected error is The error here can reach the first-level accuracy standard.

[0072] The method of the present invention can correct the data results under relatively small rainfall intensity and relatively large rainfall intensity to within the error specified by the national standard, indicating that the method of the present invention can indeed improve the measurement accuracy of the tipping bucket rain gauge.

Claims

1. A method for correcting data of a rain gauge, characterized in that: The following steps are involved: S1, calculation of simulation data: Using the caliber and resolution of the rain gauge to be corrected, at different rainfall intensities RZ i The standard bucket number N and different rainfall times S are calculated by simulating rainfall P. i ; Among them, RZ i+1 -RZ i =n, n is the interval between two consecutive rainfall intensities; i is the rainfall intensity number, i∈[1,I], I is the maximum value of the rainfall intensity number; S2, measure the average number of buckets: Under laboratory conditions, simulated rainfall P was used to experimentally obtain different rainfall intensities RZ i After multiple experiments, the number of measurements under each different rainfall intensity RZ i The average number of buckets measured under the laboratory is obtained by taking the average number of buckets N i ; S3, calculate the correction factor and dump simulation time S31, calculate the correction factor Y by the following formula i : S32, calculate the dumping simulation time T by the following formula i : S4, calculate the rainfall intensity interval coefficient K i : K i =|(Y i+1 -Y i ) / (T i+1 -T i )|;i∈[i,I-1]; S5, correcting the measured value of the tipping bucket rain gauge, including the following steps: S51, obtaining the actual time T of the dump bucket during actual use c and the actual number of buckets N c ; S52, firstly, the actual time T of the dump bucket is c Compare with the dumping simulation time obtained by S32 until T x+1 <T c ≤T x When the value of x is obtained, x is the actual rainfall intensity number; among them, the actual time of tipping bucket T c T is the time interval between two consecutive flips of the rain gauge to be corrected. x ∈[T1,T I-1 ],x∈[1,I-1]; Then calculate the corrected number of buckets N by the following formula: x And output: N x =N c ·[Y x +K x (|T c -T x |)]; Among them, Y x ∈[Y1,Y I-1 ]; K x ∈[K1,K I-1 ].

2. The data correction method of the rain gauge according to claim 1, characterized in that: 0.1≤n≤4 in S1.

3. The data correction method of the rain gauge according to claim 1, characterized in that: The standard bucket number N in S1 is calculated by the following formula: Simulated rainfall P÷resolution=standard bucket number N; The rainfall time S in S1 i Calculated by the following formula: Simulated rainfall P ÷ rainfall intensity RZ i = Rainfall time S i .

4. The data correction method of the rain gauge according to claim 1, characterized in that: The rain gauge to be corrected in S1 is a tipping bucket rain gauge.

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