JPH07248380A - Radar rainfall correcting device - Google Patents

Abstract

PURPOSE:To find radar rainfalls of respective parts in a measuring object area with high measuring accuracy by correlatively correcting rainfall strength of a radar rain gauge so that the change is put in the constant relationship with a change in corrected rainfall strength, and correcting an integral value so that the integral value is put in the constant relationship with a rainfall of an aboveground rain gauge. CONSTITUTION:A correlative correcting circuit 2 takes in rainfall strength RRi with every mesh from a radar rain gauge and last time pre correction and post correction rainfall strengths RRi-1 and RRCi-1 from a rainfall strength correcting circuit 4, and finds rainfall strength RRCi by an expression I. An integrated value correcting circuit 3 takes in the strength RRCi and rainfall strengths RGi of aboveground rain gauges (an observation unit: RGS and an observation period: ST) of respective observation meshes. The RRi is corrected according to its necessity so as to satisfy an expression II, and is inputted to the circuit 4, and post-correction strength RRi is corrected according to its necessity so that this satisfies an expression III, and is outputted to a circuit 2 and a correction value calculating circuit 5. Correction quantities of the respective meshes are found by the circuit 5, and a correct radar rainfall with every mesh is calculated by a rainfall calculating circuit 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radar rain amount correction apparatus for correcting radar rain amount obtained by a radar rain gauge to correct radar rain amount based on the amount of ground rain detected by a ground rain gauge.

[0002]

2. Description of the Related Art As a radar rain amount correction apparatus for correcting the radar rain amount obtained by a radar rain gauge to correct radar rain amount based on the ground rain amount detected by a ground rain gauge, the device shown in FIG. 2 is conventionally known. There is.

A radar rainfall amount correction apparatus 101 shown in this figure includes an area averaging circuit 102, two time averaging circuits 103, 1
04, a basic correction coefficient calculation circuit 105, a correction coefficient calculation circuit 106, and a corrected radar rainfall amount calculation circuit 107 are provided, and the radar rainfall amount obtained by the radar rain gauge is taken in and averaged in a plane. For each area that is preset by averaging in time, the average radar rainfall is calculated, and the amount of ground rainfall detected by the ground rain gauge is taken in. After calculating the average ground rainfall for each preset area, calculate the correction coefficient for each area necessary to correct the average radar rainfall with this average ground rainfall, and use the correction coefficient for each of the above. Correct the radar rainfall obtained by the radar rain gauge to obtain the correct radar rainfall.

The area averaging circuit 102 takes in the radar rainfall of the measurement target area measured by the radar rain gauge and, in advance, as shown in FIG. 4, among the meshes 111 dividing the measurement target area 110 as shown in FIG. In the designated group (each designated area 112), the radar rainfall is averaged, and among the meshes 111 in each designated area 112 as shown in FIG. 5, the mesh 111 including each ground rain gauge 113. The radar rainfall amount for each (observation mesh 114) is calculated and supplied to the time averaging circuit 103.

The time averaging circuit 103 is the area averaging circuit 1
02, the radar rainfall amount for each observation mesh 114 is taken in, and the radar rainfall amount for each observation mesh 114 is integrated in a preset averaging period unit to obtain a unit for each observation mesh 114. The radar rainfall amount per hour is calculated, and this is supplied to the basic correction coefficient calculation circuit 105 as the average radar rainfall amount.

As shown in FIG. 5, the time averaging circuit 104 also takes in the amount of ground rainfall measured by each ground rain gauge 113 installed for each observation mesh 114 in the measurement target area 110, and averages this over time. The average ground rainfall per unit time is calculated for each of the observation meshes 114, and this is supplied to the basic correction coefficient calculation circuit 105 as the average ground rainfall.

The basic correction coefficient calculation circuit 105 calculates the average radar rainfall for each observation mesh 114 output from the time average circuit 103 and the average ground rainfall for each observation mesh 114 output from the time average circuit 104. While taking in, the average ground rainfall of each observation mesh 114 is divided by the average radar rainfall of each observation mesh 114,
A correction coefficient (basic correction coefficient necessary for converting the average radar rainfall of each observation mesh 114 into an average ground rainfall) is calculated for each observation mesh 114 including each surface rain gauge 113, and this is calculated. Supply to.

The correction coefficient calculation circuit 106 outputs each observation mesh 114 output from the basic correction coefficient calculation circuit 105.
Of the basic correction coefficients, and interpolation (for example, linear interpolation) between the basic correction coefficients is performed, and the correction coefficient (average radar rainfall of each mesh 111 is averaged for each mesh 111 between the observation meshes 114). A correction coefficient necessary for conversion into ground rainfall is calculated, and these are supplied to the corrected radar rainfall calculation circuit 107.

The corrected radar rain calculation circuit 107 outputs the meshes 111 output from the correction coefficient calculation circuit 106.
The correction coefficient for each mesh and the radar rain quantity for each mesh 111 obtained by the radar rain gauge are taken in, and the radar rain quantity for each mesh 111 and the correction coefficient for each mesh 111 are acquired for each mesh 111. Each is multiplied to convert the radar rainfall amount for each mesh 111 into a ground rainfall amount for each mesh 111, and this is output as a correct radar rainfall amount.

[0010]

However, the above-described conventional radar rain amount correction apparatus 101 has the following problems.

That is, the conventional radar rainfall correction apparatus 10
1, the area averaging circuit 102 and the time averaging circuit 103
Since the average radar rainfall for each observation mesh 114 is calculated to calculate the correction coefficient for each mesh 111, an accurate correction coefficient is calculated for each mesh 111 in the case of rainfall that changes little over a wide area. However, when compensating for local rainfall or rapid rainfall,
The averaging process performed by the area averaging circuit 102 and the time averaging circuit 103 suppresses a change in rainfall, resulting in a problem that the correction accuracy is extremely reduced.

In view of the above circumstances, the present invention makes full use of the characteristics of radar rainfall obtained by surface observation by radar rain gauges and the characteristics of ground rainfall obtained by point observation by each ground rain gauge. It is an object of the present invention to provide a radar rainfall correction device capable of ensuring a high correction accuracy even in the case of rainfall that changes little over a wide area, local rainfall, or rainfall that changes drastically.

[0013]

In order to achieve the above object, the present invention provides a radar rainfall amount of a measurement target area obtained by a radar rain gauge and various places provided at each observation point in the measurement target area. In the radar rainfall correction device that takes in the respective ground rainfalls obtained by the rain gauge and corrects the radar rainfalls so that the respective ground rainfalls and the radar rainfalls have a preset relationship, the radar rainfalls Correlation correction circuit that correlates the radar rainfall intensity so that the change in the radar rainfall intensity obtained by the meter and the change in the corrected radar rainfall intensity have a constant relationship, and the correlation correction circuit obtained by this correlation correction circuit The integrated value correction time for correcting the integrated value of the radar rain intensity is adjusted so that the integrated value of the existing radar rain intensity and the integrated value of the ground rainfall obtained by each ground rain gauge have a constant relationship. And a radar rainfall correction circuit for obtaining the radar rainfall of each part of the measurement target area based on the corrected radar rainfall intensity obtained by the integrated value correction circuit and the radar rainfall of the measurement target area obtained by the radar rain gauge It is characterized by having and.

According to a second aspect of the present invention, in the radar rainfall correction apparatus according to the first aspect, the corrected radar rain intensity obtained by the integral value correction circuit is taken in, and the corrected radar rain intensity is used for each ground rainfall. A rain intensity correction circuit that corrects the corrected radar rain intensity and supplies it to the radar rain correction circuit so that it falls within the rain intensity error range obtained based on the ground rainfall obtained by the meter. It has a feature.

According to a third aspect of the present invention, in the radar rainfall amount correction apparatus according to the first or second aspect, the correlation correction circuit,
1 of integrated value correction circuit and corrected radar rainfall calculation circuit
As one of the features, it is characterized by using a device which is processed by a program.

[0016]

In the above structure, according to the first aspect of the present invention, the radar rain intensity is adjusted so that the change in the radar rain intensity obtained by the radar rain gauge by the correlation correction circuit and the change in the corrected radar rain intensity have a constant relationship. With correlation correction
The radar rainfall intensity is adjusted so that the integral value of the correlation-corrected radar rainfall intensity obtained by the correlation correction circuit by the integral value compensation circuit and the integral value of the ground rainfall intensity obtained by each ground rain gauge have a constant relationship. The integrated value is corrected, further based on the radar rainfall intensity of the measurement target area obtained by the radar rain gauge and the radar rain gauge corrected by the integrated value correction circuit by the radar rainfall correction circuit, based on the measurement target area By obtaining the radar rainfall of each part, the characteristics of the radar rainfall obtained by the surface observation by the radar rain gauge and the characteristics of the ground rainfall obtained by the point observation by each ground rain gauge can be fully utilized to cover a wide area. High correction accuracy is ensured even in the case of rainfall with little change, local rainfall or rainfall with rapid changes.

Further, in claim 2, the corrected radar rain intensity obtained by the integral correction circuit by the rainfall intensity correction circuit is taken in, and the corrected radar rain intensity is obtained by each ground rain gauge. The corrected radar rain intensity is corrected and supplied to the radar rain amount correction circuit so that it falls within the rainfall intensity error range obtained on the basis of (1).

According to the third aspect of the present invention, a device for processing by a program is used as one of the correlation correction circuit, the integrated value correction circuit, and the corrected radar rainfall amount calculation circuit, so that the system version can be easily upgraded. To do.

[0019]

1 is a block diagram showing an embodiment of a radar rainfall correction apparatus according to the present invention. The radar rainfall correction apparatus 1 shown in this figure includes a correlation correction circuit 2 and an integrated value correction circuit 3.
And a correction value calculation circuit 5 and a corrected radar rainfall calculation circuit 6 are provided, and the radar rainfall intensity obtained by the radar rain gauge is taken in and correlated with this radar rainfall intensity. After performing the correction, based on the radar rain intensity after this correlation correction and each ground rainfall obtained by each ground rain gauge, after correcting the radar rain intensity by performing integral value correction and rainfall intensity correction, The correction amount for each mesh is calculated based on the difference between the corrected radar rain intensity and the radar rainfall amount, and the radar rain amount of each mesh obtained by the radar rain gauge is corrected by these correction amounts to correct the radar rain amount. Make it rain.

The correlation correction circuit 2 performs correlation correction and integrated value correction on the radar rain intensity for each mesh output from the radar rain gauge and the previous radar rain intensity output from the rainfall intensity correction circuit 4. Taking in the corrected rainfall intensity obtained by performing the rainfall intensity correction, there is a certain correlation between the radar rainfall rainfall intensity change and the corrected rainfall intensity change, and the following equation holds: RRC _i -RRC _i-1 = RR _i -RR _i-1 (1) where RRC: Rainfall intensity after correction (mm / h) RR: Radar rainfall intensity (mm / h) i: Time Value shown) The calculation of the following equation is performed to correct the rainfall intensity of radar rainfall, and this is supplied to the integrated value correction circuit 3 as the rainfall intensity after correlation correction.

RRC _i = RR _i + (RRC _i-1 −RR _i-1 ) (2) The integrated value correction circuit 3 calculates the radar rainfall intensity of this time output from the correlation correction circuit 2 and the observation meshes. Take in the amount of surface rainfall output from each surface rain gauge provided,
The amount of ground rainfall is converted into rainfall intensity by a preset conversion formula, and it is determined whether or not the rainfall intensity and the radar rainfall intensity satisfy the following formula.

0 ≦ Σ (RRC _i −RG _i ) ≦ RGS / ST (3) where RG: rainfall intensity (m) obtained by converting ground rainfall
m / h) RGS: Ground rain gauge observation unit (mm / pulse) ST: Observation cycle (h) i: Time (value indicating the observation cycle) If this equation (3) is not satisfied, ground rainfall is calculated. It is judged that the integrated value of the difference between the rainfall intensity obtained by converting the rainfall amount obtained by the total measurement and the rainfall intensity of the radar rainfall amount is outside the observation error range that occurs in one observation cycle, and this must be satisfied. The radar rainfall intensity is corrected and supplied to the rainfall intensity correction circuit 4 so that there is as little unnatural fluctuation as possible depending on the number of observations that could not be performed, and if the formula (3) is satisfied,
It is determined that the integrated value of the difference between the rainfall intensity obtained by converting the rainfall amount obtained by the ground rain gauge and the rainfall intensity of the radar rainfall amount is within an observation error range that occurs during one observation cycle, and the radar rainfall amount is determined. The intensity is supplied as it is to the rainfall intensity correction circuit 4.

The rainfall intensity correction circuit 4 takes in the radar rainfall intensity after the integrated value correction output from the integrated value correction circuit 3 and determines whether or not it satisfies the following equation.

[0024]

## EQU1 ## RG _i − (RGS / ST) ≦ RRC _i ≦ RG _i + (RGS / ST) (4) If the equation (4) is not satisfied, the radar rainfall intensity after the integral value correction is performed. Is outside the error range of the rainfall intensity obtained based on the amount of ground rainfall, and the radar rainfall intensity after the integral value correction is corrected so that the correction amount is the smallest within the range that satisfies the formula (4). And supplies it to the correlation correction circuit 2 and the correction value calculation circuit 5, and also (4)
If the formula is satisfied, it is determined that the radar rainfall intensity after the integral correction is within the error range of the rainfall intensity obtained based on the amount of ground rainfall, and the radar rainfall intensity after the integral correction is used as it is, and the correlation is corrected. It is supplied to the correction circuit 2 and the correction value calculation circuit 3.

The correction value calculation circuit 5 outputs the radar rain intensity after the rain intensity correction output from the rain intensity correction circuit 4,
The radar rain intensity of this time is taken in, the difference between them is calculated to obtain the correction amount (RRC-RR) of this time, and the correction amount H of each observation mesh in which each ground rain gauge is provided.
(However, H = RRC-RR) and the calculation shown in the following formula based on the mesh coordinate (X, Y), and the relational expression between the mesh coordinate (X, Y) and the correction amount H of each observation mesh. The coefficients a, b, and c that define

AX + bY + c = H (5) Then, using these coefficients a, b, and c, the correction amount H for each mesh other than the above-mentioned observation meshes is obtained, and after each correction amount H is corrected Radar rainfall calculation circuit 6
Supply to.

The corrected radar rainfall amount calculation circuit 6 outputs the correction amount H for each mesh output from the correction value calculation circuit 5,
The radar rainfall for each mesh obtained by the radar rain gauge is taken in, and the radar rainfall for each mesh and the correction value H for each mesh are obtained for each mesh.
The radar rainfall amount for each mesh is added to be converted into the ground rainfall amount for each mesh, and this is output as the correct radar rainfall amount.

As described above, in this embodiment, the radar rainfall intensity obtained by the radar rain gauge is taken in, the correlation is corrected with respect to the radar rainfall intensity, and the radar rainfall intensity after the correlation correction is performed. Based on each surface rainfall obtained by each surface rain gauge, after correcting the radar rainfall intensity by performing integral value correction and rainfall intensity correction, based on the difference between the radar rainfall intensity after correction and the radar rainfall amount. The correction amount H for each mesh is calculated, and the radar rain amount of each mesh obtained by the radar rain gauge is corrected by these correction amounts H to correct the radar rain amount. The characteristics of radar rainfall obtained by static observation and the characteristics of surface rainfall obtained by point observation by each surface rain gauge are fully utilized, and even in the case of rainfall with little change over a wide area, local rainfall Even when the heavy rainfall and variations can is to ensure a high correction accuracy.

Further, in the above-described embodiment, as the correlation correction, the radar rainfall amount is changed so that the radar rainfall amount change for each observation mesh output from the radar rain gauge and the corrected radar rainfall intensity change are equal. The intensity is corrected, but another correlation correction method, for example, the correction is performed assuming that the ratio of the radar rainfall rainfall intensity one observation cycle before and the corrected radar rainfall intensity is equal. Is also good. Further, when the correction by the integrated value correction and the rainfall intensity correction is performed, the correction may be performed so as to be the center within the range. Even in this case, the same effect as that of the above-described embodiment can be obtained.

Further, in the above-described embodiment, as a method for obtaining the correction amount H of the mesh not provided with the ground rain gauge, the correction amount H of each observation mesh is used to calculate each coefficient a,
b and c are calculated, and the correction amount H of each mesh is calculated based on these coefficients a, b and c and the coordinates (X, Y) of each mesh. Weighting the correction amount H of each observation mesh,
The correction amount H of each mesh may be obtained by performing approximation. Even in this case, the same effect as that of the above-described embodiment can be obtained.

Further, in the above-described embodiment, the correlation correction circuit 2, the integrated value correction circuit 3, the rainfall intensity correction circuit 4, the correction value calculation circuit 5 and the corrected radar rainfall calculation circuit 6 are described as discrete circuits. However, these correlation correction circuit 2, integrated value correction circuit 3, rainfall intensity correction circuit 4,
All or necessary parts of the correction value calculation circuit 5 and the corrected radar rainfall calculation circuit 6 may be processed by a computer device (device that operates according to a program).
By doing so, the processing content can be changed only by changing the program without changing the hardware part, and the version upgrade of the system can be facilitated.

[0032]

As described above, according to the present invention, in claim 1, the characteristics of the radar rainfall amount obtained by the surface observation by the radar rain gauge and the point observation by each ground rain gauge are obtained. By making full use of the characteristics of surface rainfall, it is possible to ensure high correction accuracy even in the case of rainfall that does not change much in a wide area, local rainfall or rainfall that changes drastically. Also,
According to the second aspect, it is possible to ensure a higher correction accuracy than that of the first aspect. Further, in claim 3, the system version can be easily upgraded.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a radar rainfall correction apparatus according to the present invention.

FIG. 2 is a block diagram showing an example of a conventionally known radar rainfall correction device.

FIG. 3 is a schematic diagram showing an operation example of the radar rainfall correction apparatus shown in FIG.

FIG. 4 is a schematic diagram showing an operation example of the radar rainfall correction apparatus shown in FIG.

5 is a schematic diagram showing an operation example of the radar rainfall correction apparatus shown in FIG.

[Explanation of symbols]

 1 Radar Rainfall Correction Device 2 Correlation Correction Circuit 3 Integrated Value Correction Circuit 4 Rainfall Intensity Correction Circuit 5 Correction Value Calculation Circuit 6 Corrected Radar Rainfall Calculation Circuit

Claims (3)

[Claims] 1. Incorporating a radar rainfall amount of a measurement target area obtained by a radar rain gauge and each ground rainfall amount obtained by each ground rain gauge provided at each observation point in the measurement target area, In a radar rainfall correction device that corrects the radar rainfall so that the rainfall and the radar rainfall have a preset relationship, a change in the radar rainfall intensity obtained by the radar rain gauge and the corrected radar rainfall intensity Correlation correction circuit that correlatively corrects the radar rainfall intensity so that there is a constant relationship with the change of the radar rainfall intensity, and the integrated value of the radar rainfall intensity corrected by the correlation obtained by this correlation correction circuit and obtained by each ground rain gauge. The integrated value correction circuit that corrects the integrated value of the radar rainfall intensity so that the integrated value of the ground rainfall has a constant relationship, and the corrected value obtained by this integrated value correction circuit. A radar rainfall amount correction circuit, comprising: a radar rainfall amount correction circuit for obtaining the radar rainfall amount of each part of the measurement target region based on the radar rainfall intensity and the radar rain amount of the measurement target region obtained by the radar rain gauge. . 2. A rainfall intensity error range obtained by taking in the corrected radar rainfall intensity obtained by the integral correction circuit and obtaining the corrected radar rainfall intensity based on the amount of ground rainfall obtained by each ground rain gauge. 2. The radar rain amount correction apparatus according to claim 1, further comprising a rain intensity correction circuit for correcting the corrected radar rain amount intensity and supplying the corrected radar rain amount intensity to the radar rain amount correction circuit. 3. A program processing device is used as one of the correlation correction circuit, the integral value correction circuit, and the corrected radar rainfall amount calculation circuit.
Alternatively, the radar rainfall correction device described in 2.