CN105388467A - Method of correcting Doppler weather radar echo attenuation - Google Patents

Abstract

The invention discloses a method of correcting Doppler weather radar echo attenuation. By using features of radar echoes and analyzing an echo crossing correlation coefficient in an echo overlapping area of the current radar and a near radar station at the contour plane position at the same time, the optimal function parameter in the current weather condition is searched, the optimal echo gain function is further obtained, a radar echo intensity value after reasonable gain is calculated through the function, the Doppler weather radar echo attenuation can be effectively corrected, and the result is closer to the actual weather condition.

Description

A kind of method revising Doppler radar echo attenutation

Technical field

The present invention relates to the technology that the radar return in different weather environment is revised, particularly relate to a kind of method revising Doppler radar echo attenutation.

Background technology

, scattering and refraction can be there is when running into the suspended particles such as air molecule, gasoloid, water dust, raindrop and ice crystal, thus electromagnetic wave is weakened in the electromagnetic wave that Doppler radar (hereinafter referred to as radar) is launched.Along with electromagnetic wave is along the increase of travel path distance, this effect that weakens can be more and more obvious, and then the echo generation distortion causing detections of radar to arrive, and finally has influence on the various application based on GPR Detection Data, such as, can affect the accuracy of closing on weather forecast.But because the attenuation process of electromagnetic wave on travel path is by the combined influence of many factors in air, and current shortage can the Atmospheric components detecting devices of operational use on a large scale, and therefore, the accurate correction for this decay is very difficult.

Summary of the invention

The object of the invention is to the defect overcoming above-mentioned prior art, provide a kind of method of Doppler radar echo attenutation being carried out to accurately revise, the method concrete steps are as follows:

(1) set radar A as the Doppler radar of echo attenutation correction need be carried out, choose adjacent with radar A geographic position and that model is identical radar B, and these two radars of random selecting are there being strong convective weather, and (strong convective weather refers to: owing to not having strong convective weather process, particularly during clear sky, the reflective particles such as enough steam, ice crystal are not had in air, now the echo that receives of radar is very weak, does not even have echo.Thus there is not obvious echo attenutation yet.) process time synchronization base data file;

(2) by polar coordinate system, plane right-angle coordinate form is converted to by formula (2) and formula (3) to echo strength data (also referred to as baseis reflectivity data) in radar A base data file, wherein, any point (θ under formula (3) expression polar coordinate system, r) with (x under plane right-angle coordinate, y) the coordinate corresponding relation between, (in formula (2), first left equal sign represents P ' _{(x, y)}with P ' _{(θ, r)}coordinate position of equal value, second equal sign represents that the value that (x, y) puts is calculated by the base data echo strength value of some points that (θ, r) puts and position is adjacent); Again the echo strength value calculated by formula (2) is revised by formula (1), in formula (1), two variable element h and a increase progressively value by respective step-length respectively, obtain the many groups of correction echo strength value P changed with h and a parameter value variation _{(x, y)};

Wherein each formula is as follows:

Echo strength value correction formula is $P_{(x,y)}=P_{(\mathrm{\θ},r)}=\frac{{P^{,}}_{(\mathrm{\θ},r)}}{e^{-1\×\underset{j=1}{\overset{r}{\Σ}}{\mathrm{hP}}_{(\mathrm{\θ},j)}^a}}---\left(1\right),$

Under plane right-angle coordinate, the echo strength value computing formula of any point is

Polar coordinate system and plane right-angle coordinate transformational relation are $\left\{\begin{array}{c}\mathrm{\θ}=\frac{\arcsin \left(\frac{x-X_0}{r}\right)\·180}{\mathrm{\π}}\\ r=\sqrt{x^2+y^2}\end{array}\right.---\left(3\right),$

In formula, point (θ, r) be any point under a certain elevation angle in above-mentioned radar A base data file, θ represents the position angle of this point, r is the distance between this point and radar A central point, azimuth angle theta ∈ [0,360] and be 0 degree with direct north, (in base data, r is the range bin number of this point reflection rate in radial direction, and therefore r is less than or equal to the maximum effective radius of radar detection.) point (x, y) is the corresponding coordinate in plane right-angle coordinate of point (θ, r); P _{(x, y)}and P _{(θ, r)}represent the revised echo strength value of this point, the former is plane right-angle coordinate, and the latter is polar coordinate system; P ' _{(x, y)}and P ' _{(θ, r)}represent the echo strength value at this some place adopting formula (2) to calculate, the former is plane right-angle coordinate, and the latter is polar coordinate system, (wherein (x, y) be converted to by formula (3) with the corresponding relation of (θ, r)); H and a is variable element, h ∈ [1 × 10 ^-7, 1 × 10 ^-6], step-length is 1 × 10 ^-7; A ∈ [0.5,1.5], step-length is 0.1; put under representing the current elevation angle with for position angle, the echo strength value of the point at distance radar i place, this value also obtains by the base data file of radar A, (in formula (2), value is θ-1, θ, θ+1, i value be r-1, r and r+1); P _{(θ, j)}represent under the current elevation angle with point (θ, r) the echo strength value at distance radar j place in same radial direction, (this value obtains by the base data file of radar A), j is as the variable in calculating, in formula (1), j value is [1, r]; At X ₀, Y ₀it is radar A center point coordinate under plane right-angle coordinate;

As stated above, 9 elevations angle in the base data file of radar A are revised respectively, random selecting contour plane again, adopt general interpolation algorithm (as bilinear interpolation, or anti-distance weighting interpolation), utilize all results at above-mentioned 9 elevations angle of trying to achieve, calculate the revised echo strength PA of radar A on this contour plane, as shown in Figure 3, left side ordinate represents the height above distance radar center point, unit is km, right side ordinate represents the elevation angle of radar detection, horizontal ordinate represents the distance with radar center point in horizontal direction, unit is km, the thickest black line represents required contour plane (3km height), on this face, the echo strength value of each point is drawn by the echo strength interpolation calculation at each elevation angle on same horizontal ordinate,

(3) identical process is carried out to radar B base data, obtain the revised echo strength PB of radar B and identical contour plane in step (2);

(4) above-mentioned two radar scanning overlapping regions delimited, the mode of delimiting for: the latitude and longitude coordinates both calculating according to the geographic position of two radars is poor, △ x in plane right-angle coordinate and △ y is corresponded to by this mathematic interpolation, △ x and △ y is defined as m and n respectively, (as shown in Figure 2, in figure, two circles represent the effective scanning region of radar A and radar B respectively, two centers of circle represent two radars position) region that is made up of m and n is a rectangle; By formula (4), calculate the revised radar A contour plane echo strength and the related coefficient of radar B contour plane echo strength in this overlapping rectangles region that are obtained respectively by above-mentioned steps (2) and step (3);

Calculation of correlation factor formula is

${\mathrm{\γ}}_{(a,h,k)}=\frac{\underset{z=-k}{\overset{k}{\Σ}}\underset{x=0}{\overset{m+z}{\Σ}}\underset{y=0}{\overset{n+z}{\Σ}}(P{0}_{(x,y)}-\stackrel{\‾}{P0})(P{1}_{(x,y)}-\stackrel{\‾}{P1})}{\sqrt{\underset{z=-k}{\overset{k}{\Σ}}\underset{x=0}{\overset{m+z}{\Σ}}\underset{y=0}{\overset{n+z}{\Σ}}{(P{0}_{(x,y)}-\stackrel{\‾}{P0})}^2.\underset{z=-k}{\overset{k}{\Σ}}\underset{x=0}{\overset{m+z}{\Σ}}\underset{y=0}{\overset{n+z}{\Σ}}{(P{1}_{(x,y)}-\stackrel{\‾}{P1})}^2}}---\left(4\right)$

In formula, P0 _{(x, y)}and P1 _{(x, y)}represent that certain a bit revises back echo intensity, i.e. P0 to this contour plane place radar A and radar B in above-mentioned rectangular extent respectively _{(x, y)}∈ PA, P1 _{(x, y)}∈ PB, represent radar A in the rectangular area of above-mentioned contour plane the mean value of correction back echo intensity a little; In like manner, represent radar B in the rectangular area of above-mentioned contour plane the mean value of correction back echo intensity a little; K is a distance adjustment parameter, (for adjusting deviation when plane right-angle coordinate and latitude and longitude coordinates system change) integer that span is k ∈ [0,19], and step-length is 1;

(5) scope of k is set, to γ _{(a, h, k)}when getting different k, a and h, being calculated respectively by formula (4) and obtaining a related coefficient γ _{(a, h, k)}, record γ _{(a, h, k)}the value of a and h when being worth maximum, is the optimal parameter of radar A under current atmospheric situation, incites somebody to action the P that now a and h value substitution formula (1) calculates _{(x, y)}or P _{(θ, r)}be the echo strength value of radar A attenuation correction the best.

Further design of the present invention is:

General interpolation algorithm can adopt bilinear interpolation or anti-distance weighting interpolation.

Use same computing method, the optimal parameter of radar B under current atmospheric situation can be determined, obtain the echo strength value of radar B attenuation correction the best.

Tool of the present invention has the following advantages:

Utilize the characteristic of radar return, and by analyzing current radar and the echo cross-correlation of contiguous radar station in the echo overlapping region of synchronization contour plane position, function parameter optimum under seeking current weather condition, and then obtain an optimum echo gain function, function calculates the radar echo intensity value after reasonable gain thus, effectively revise Doppler radar echo attenutation, its result is closer to the actual state of air.

Accompanying drawing explanation

Fig. 1 is the schematic flow sheet of the method for correction Doppler radar of the present invention echo attenutation.

Fig. 2 is the schematic diagram of adjacent two radar return overlapping regions, geographic position.

Fig. 3 is the schematic diagram at radar contour plane position and the radar elevation angle.

Embodiment

Embodiment one:

Process flow diagram as shown in Figure 1, the present embodiment adopts step described as follows to carry out corrected Calculation:

Step one, builds an echo gain function, and this argument of function should comprise distance that electromagnetic wave propagated, electromagnetic wave by way of the decay produced everywhere.Simultaneously, function also should meet following relationship: for the clear sky of the weather phenomena such as cloudless, rain, in effective radius of investigation that radar is specified, because of launch electromagnetic wave and echo strength much larger than the decay in transmitting procedure, actual ghosts intensity now should be approximately equal to detected echo strength value; The echo strength value that function calculates gained should meet objective law, can not be excessive or too small, and for S-band radar, generally functional value should between 0 to 80; Due to the restriction of detecting devices and condition, pad value everywhere cannot be quantized, can only by the intensity counter degree that push away electromagnetic wave attenuation of electromagnetic wave by way of radar return everywhere.According to the detection principle of radar and the feature of data structure thereof, the function of structure can be expressed as formula (1).

Step 2, choose a radar A, and choose adjacent with radar A geographic position and that model is identical radar B, and the base data file of these two radars of random selecting synchronization when there being strong convective weather process, echo strength data (also referred to as baseis reflectivity data) in base data are converted to plane right-angle coordinate by the data layout of polar coordinate system by formula (2) and formula (3), wherein, any point (θ under formula (3) expression polar coordinate system, r) with (x under plane right-angle coordinate, y) the coordinate corresponding relation between, the computing method of the echo strength value of each point under formula (2) expression plane right-angle coordinate, wherein in formula (2), first left equal sign represents P ' _{(x, y)}with P ' _{(θ, r)}coordinate position of equal value, second equal sign represents that the echo strength value that (x, y) puts is calculated by the base data echo strength value of some points that (θ, r) puts and position is adjacent.Again the echo strength value calculated by formula (2) is revised by formula (1), formula (1) comprises two variable elements, be respectively h and a, these two parameters are respectively in its span, increase progressively by respective step-length, obtain thus many groups with h and a parameter value variation different correction echo strength value P _{(x, y)};

$P_{(x,y)}=P_{(\mathrm{\θ},r)}=\frac{{P^{\′}}_{(\mathrm{\θ},r)}}{e^{-1\×\underset{j=1}{\overset{r}{\Σ}}{\mathrm{hP}}_{(\mathrm{\θ},j)}^a}}---\left(1\right),$

$\left\{\begin{array}{c}\mathrm{\θ}=\frac{\arcsin \left(\frac{x-X_0}{r}\right)\·180}{\mathrm{\π}}\\ r=\sqrt{x^2+y^2}\end{array}\right.---\left(3\right),$

In formula, point (θ, r) be any point under a certain elevation angle in above-mentioned radar A base data file, θ represents the position angle of this point, r is the distance between this point and radar A central point, azimuth angle theta ∈ [0,360] and be 0 degree with direct north, (in base data, r is the range bin number of this point reflection rate in radial direction, and therefore r is less than or equal to the maximum effective radius of radar detection.) point (x, y) is the corresponding coordinate in plane right-angle coordinate of point (θ, r); P _{(x, y)}and P _{(θ, r)}represent the revised echo strength value of this point, the former is plane right-angle coordinate, and the latter is polar coordinate system; P ' _{(x, y)}and P ' _{(θ, r)}represent the echo strength value at this some place adopting formula (2) to calculate, the former is plane right-angle coordinate, and the latter is polar coordinate system, (wherein (x, y) be converted to by formula (3) with the corresponding relation of (θ, r)); H and a is variable element, h ∈ [1 × 10 ^-7, 1 × 10 ^-6], step-length is 1 × 10 ^-7; A ∈ [0.5,1.5], step-length is 0.1; put under representing the current elevation angle with for position angle, the echo strength value of the point at distance radar i place, this value also obtains by the base data file of radar A, (in formula (2), value is θ-1, θ, θ+1, i value be r-1, r and r+1); P _{(θ, j)}represent under the current elevation angle with point (θ, r) the echo strength value at distance radar j place in same radial direction, (this value obtains by the base data file of radar A), j is as the variable in calculating, in formula (1), j value is [1, r]; At X ₀, Y ₀it is radar A center point coordinate under plane right-angle coordinate; The center of circle in corresponding polar coordinate system.

Step 3, as as stated above, 9 elevations angle in the base data file of radar A are revised respectively, random selecting contour plane again, adopt general interpolation algorithm (as bilinear interpolation or anti-distance weighting interpolation), utilize all results at above-mentioned 9 elevations angle of trying to achieve, calculate the revised echo strength PA of radar on this contour plane, as shown in Figure 3, left side ordinate represents the height above distance radar center point, unit is km, right side ordinate represents the elevation angle of radar detection, horizontal ordinate represents the distance with radar center point in horizontal direction, unit is km, the thickest black line represents required contour plane (3km height), on this face, the echo strength value of each point is drawn by the echo strength interpolation calculation at each elevation angle on same horizontal ordinate.。

Step 4, choose an and radar B that model identical adjacent with current radar A position, by step 2 and step 3 process, calculate in the effective radius of investigation of this radar, in plane right-angle coordinate with same contour plane position correction in step 3 after echo strength value PB.

Step 5, delimit two radar scanning overlapping regions, the mode of delimiting for: the latitude and longitude coordinates both calculating according to the geographic position of two radars is poor, △ x in plane right-angle coordinate and △ y is corresponded to by this mathematic interpolation, △ x and △ y is defined as m and n respectively, and as shown in Figure 2, in figure, two circles represent the effective scanning region of two radars respectively, two centers of circle represent two radars position, the region be made up of m and n is a rectangle.

Step 6, builds Calculation of correlation factor formula 4, calculates the related coefficient of echo strength in this overlapping rectangles region on revised two same contour planes of radar of being obtained respectively by step 5.

${\mathrm{\γ}}_{(a,h,k)}=\frac{\underset{z=-k}{\overset{k}{\Σ}}\underset{x=0}{\overset{m+z}{\Σ}}\underset{y=0}{\overset{n+z}{\Σ}}(P{0}_{(x,y)}-\stackrel{\‾}{P0})(P{1}_{(x,y)}-\stackrel{\‾}{P1})}{\sqrt{\underset{z=-k}{\overset{k}{\Σ}}\underset{x=0}{\overset{m+z}{\Σ}}\underset{y=0}{\overset{n+z}{\Σ}}{(P{0}_{(x,y)}-\stackrel{\‾}{P0})}^2.\underset{z=-k}{\overset{k}{\Σ}}\underset{x=0}{\overset{m+z}{\Σ}}\underset{y=0}{\overset{n+z}{\Σ}}{(P{1}_{(x,y)}-\stackrel{\‾}{P1})}^2}}$ Formula 4

In formula, P0 _{(x, y)}and P1 _{(x, y)}when representing this contour plane respectively, in above-mentioned rectangular extent, certain a bit revises back echo intensity, i.e. P0 to radar A and radar B _{(x, y)}∈ PA, P1 _{(x, y)}∈ PB, represent radar A in the rectangular area of above-mentioned contour plane the mean value of correction back echo intensity a little; In like manner, represent radar B in the rectangular area of above-mentioned contour plane the mean value of correction back echo intensity a little; K is a distance adjustment parameter, and (for adjusting deviation when plane right-angle coordinate and latitude and longitude coordinates system change) integer that span is k ∈ [0,19], step-length is 1, and is integer.At γ _{(a, h, k)}when different a, h and k values, the related coefficient calculated respectively.

Step 7, gets γ _{(a, h, k)}a and h when result is maximum, is the optimal parameter of radar formula 1 and formula 2 under current atmospheric situation, and the P (x, y) gone out by this coefficient calculations is the echo strength value of attenuation correction the best.

Application example one:

The Doppler radar of existing random selecting Guangzhou, each S-band in riverhead, wherein, the radar in Guangzhou is as object of the invention process, and the radar at riverhead is as the adjacent radar station of the object implemented.

First, when random selecting has strong convective weather to occur, these two radars are at the base data file of synchronization, as: Z_RADR_I_Z9200_20140521033000_O_DOR_SA_CAP.bin and Z_RADR_I_Z9762_20140521033000_O_DOR_SA_CAP.bin, the former is Guangzhou radar data, and the latter is riverhead radar data.

By the step 2 in calculation procedure in embodiment one and step 3, the echo strength data of 9 elevations angle (radar observation pattern is VCP21) in the base data of Guangzhou are converted to plane right-angle coordinate by the data layout of polar coordinate system by formula (2) and formula (3).In the process of this conversion and interpolation, on planimetric rectangular coordinates, the echo strength value of each lattice point uses formula (1) to revise.

Due in formula 1, h ∈ [1 × 10 ^-7, 1 × 10 ^-6], h is with step-length 1 × 10 ^-7increase progressively, a ∈ [0.5,1.5], a are 0.1 to increase progressively with step-length, and therefore, calculating the data file number exported is: 9 × 11 × 11=1089.Wherein, h and a that each group is determined, has the data file at 9 different elevations angle.Set a height, as 3000 meters high, for the file at each group 9 elevation angle, use bilinear interpolation algorithm (also can adopt anti-distance weighting interpolation algorithm), calculate the data file of the echo strength after exporting this contour plane position correction.

By the computation process same with Guangzhou base data, identical computation process is done to riverhead base data, obtain with Guangzhou radar at same contour plane position correction back echo intensity data files.

By step 5 mode, delimit the scanning overlapping region of Guangzhou radar and riverhead radar.First, the geographic position according to these two radars: Guangzhou radar (east longitude 113.355 °, north latitude 23.004 °), riverhead radar (east longitude 114.607 °, north latitude 23.690 °), the latitude and longitude coordinates of both calculating is poor:

Difference of longitude △ lon=113.355 °-114.607 °=-1.252 °

Difference of latitude △ lat=23.004 °-23.690 °=-0.686 °

The relation of base area ball warp latitude and distance, can calculate:

M ≈ ABS (| △ lon| × 111 kilometer/degree)=ABS (1.252 × 111) ≈ 139

N ≈ ABS (| △ lat| × 111 kilometer/degree × Cos ((Guangzhou latitude+riverhead latitude)/2))=ABS (0.686 × 111 × (23.004 °+23.690 °)/2) ≈ 70

Wherein, ABS represents and asks absolute value.As shown in Figure 2, in figure, two circles represent the effective scanning region of two radars respectively, two centers of circle represent two radars position, the region be made up of m and n is a rectangle.

Setting P0 _{(x, y)}and P1 _{(x, y)}represent Guangzhou radar and riverhead radar any point correction back echo intensity in the rectangular extent of 3000 meters of high contour planes respectively, represent Guangzhou radar in the rectangular area of this contour plane the mean value of correction back echo intensity a little; In like manner, represent riverhead radar in the rectangular area of this contour plane the mean value of correction back echo intensity a little; K is a distance adjustment parameter, (for adjusting deviation when plane right-angle coordinate and latitude and longitude coordinates system change) integer that span is k ∈ [0,19], and step-length is 1;

H and a that each group corresponding is determined, substituting into formula 4 by revising back echo data file in the above-mentioned rectangular extent in same contour plane position selected by Guangzhou, riverhead, calculating related coefficient γ _{(a, h, k)}.

Simultaneously in formula 4, k ∈ [0,19], and k round numbers, therefore in computation process, carry out value successively to k, and needs have carried out 11 × 11 × 20=2420 time calculating altogether, obtain 2420 γ _{(a, h, k)}.The γ that selected value is maximum _{(a, h, k)}, a and h is now optimal parameter, and namely the data file of the echo that a and h is corresponding have recorded the echo strength value of Guangzhou radar data attenuation correction the best.

Above-mentioned a and h determined also is the optimal parameter of riverhead radar.

Due to above step, operand is larger in actual applications, therefore, for close atmospheric conditions and weather phenomenon, only need carry out in first time the parameter value recording optimum a and h when above-mentioned steps calculates, in application after this, directly this and h is substituted into formula 2.The P calculated thus _{(x, y)}be the echo strength value of attenuation correction the best.For different atmospheric conditions or weather phenomenon, different a and h parameter values should be adopted.

Claims (3)

1. revise a method for Doppler radar echo attenutation, it is characterized in that, comprise the following steps:

(1) set radar A as the Doppler radar of echo attenutation correction need be carried out, choose adjacent with radar A geographic position and that model is identical radar B, and the base data file of these two radars of random selecting synchronization when there being strong convective weather process;

(2) by polar coordinate system, plane right-angle coordinate form is converted to by formula (2) and formula (3) to echo strength data in radar A base data file, wherein, any point (θ under formula (3) expression polar coordinate system, r) the coordinate corresponding relation and under plane right-angle coordinate between (x, y); Again the echo strength value calculated by formula (2) is revised by formula (1), in formula (1), two variable element h and a increase progressively value by respective step-length respectively, obtain the many groups of correction echo strength value P changed with h and a parameter value variation _{(x, y)};

Wherein each formula is as follows:

Echo strength value correction formula is $P_{(x,y)}=P_{(\mathrm{\θ},r)}=\frac{{P^{,}}_{(\mathrm{\θ},r)}}{e^{-1\×\underset{j=1}{\overset{r}{\Σ}}{\mathrm{hP}}_{(\mathrm{\θ},j)}^a}}---\left(1\right),$

Under plane right-angle coordinate, the echo strength value computing formula of any point is

Polar coordinate system and plane right-angle coordinate transformational relation are $\left\{\begin{array}{c}\mathrm{\θ}=\frac{\arcsin \left(\frac{x-X_0}{r}\right)\·180}{\mathrm{\π}}\\ r=\sqrt{x^2+y^2}\end{array}\right.---\left(3\right),$

In formula, point (θ, r) be any point under a certain elevation angle in above-mentioned radar A base data file, θ represents the position angle of this point, and r is the distance between this point and radar A central point, azimuth angle theta ∈ [0,360] and be 0 degree with direct north, point (x, y) is the corresponding coordinate in plane right-angle coordinate of point (θ, r); P _{(x, y)}and P _{(θ, r)}represent the revised echo strength value of this point, the former is plane right-angle coordinate, and the latter is polar coordinate system; P ' _{(x, y)}and P ' _{(θ, r)}represent the echo strength value at this some place adopting formula (2) to calculate, the former is plane right-angle coordinate, and the latter is polar coordinate system; H and a is variable element, h ∈ [1 × 10 ^-7, 1 × 10 ^-6], step-length is 1 × 10 ^-7; A ∈ [0.5,1.5], step-length is 0.1; put under representing the current elevation angle with for position angle, the echo strength value of the point at distance radar i place, this value also obtains by the base data file of radar A; P _{(θ, j)}represent the echo strength value with distance radar j place in the same radial direction of point (θ, r) under the current elevation angle, j is as the variable in calculating, and in formula (1), j value is [1, r]; At X ₀, Y ₀it is radar A center point coordinate under plane right-angle coordinate;

As stated above, the echo strength at 9 elevations angle in the base data file of radar A is revised respectively, choose a certain height again, utilize all results at above-mentioned 9 elevations angle of trying to achieve, adopt general interpolation algorithm to calculate the revised echo strength PA of radar A on this contour plane;

(3) identical process is carried out to radar B base data, obtain the revised echo strength PB of radar B and identical contour plane in step (2);

(4) above-mentioned two radar scanning overlapping regions delimited, the mode of delimiting for: the latitude and longitude coordinates both calculating according to the geographic position of two radars is poor, △ x in plane right-angle coordinate and △ y is corresponded to by this mathematic interpolation, △ x and △ y is defined as m and n respectively, and the region be made up of m and n is a rectangle; By formula (4), calculate the revised radar A contour plane echo strength and the related coefficient of radar B contour plane echo strength in this overlapping rectangles region that are obtained respectively by above-mentioned steps (2) and step (3);

Calculation of correlation factor formula is

${\mathrm{\γ}}_{(a,h,k)}=\frac{\underset{z=-k}{\overset{k}{\Σ}}\underset{x=0}{\overset{m+z}{\Σ}}\underset{y=0}{\overset{n+z}{\Σ}}(P{0}_{(x,y)}-\stackrel{\‾}{P0})(P{1}_{(x,y)}-\stackrel{\‾}{P1})}{\sqrt{\underset{z=-k}{\overset{k}{\Σ}}\underset{x=0}{\overset{m+z}{\Σ}}\underset{y=0}{\overset{n+z}{\Σ}}{(P{0}_{(x,y)}-\stackrel{\‾}{P0})}^2.\underset{z=-k}{\overset{k}{\Σ}}\underset{x=0}{\overset{m+z}{\Σ}}\underset{y=0}{\overset{n+z}{\Σ}}{(P{1}_{(x,y)}-\stackrel{\‾}{P1})}^2}}---\left(4\right)$

In formula, P0 _{(x, y)}and P1 _{(x, y)}represent that certain a bit revises back echo intensity, i.e. P0 to this contour plane place radar A and radar B in above-mentioned rectangular extent respectively _{(x, y)}∈ PA, P1 _{(x, y)}∈ PB, represent radar A in the rectangular area of above-mentioned contour plane the mean value of correction back echo intensity a little; In like manner, represent radar B in the rectangular area of above-mentioned contour plane the mean value of correction back echo intensity a little; K is a distance adjustment parameter, and span is the integer of k ∈ [0,19], and step-length is 1;

(5) scope of k is set, to γ _{(a, h, k)}when getting different k, a and h and carrying out value, calculated respectively by formula (4) and obtain a related coefficient γ _{(a, h, k)}, record γ _{(a, h, k)}the value of a and h when being worth maximum, is the optimal parameter of radar A under current atmospheric situation, incites somebody to action the P that now a and h value substitution formula (1) calculates _{(x, y)}or P _{(θ, r)}be the echo strength value of radar A attenuation correction the best.

2. the method for correction Doppler radar according to claim 1 echo attenutation, is characterized in that: described general interpolation algorithm adopts bilinear interpolation or anti-distance weighting interpolation.

3. the method for correction Doppler radar according to claim 1 and 2 echo attenutation, is characterized in that: as stated above, determines the optimal parameter of radar B under current atmospheric situation, obtains the echo strength value of radar B attenuation correction the best.