Rain fall attenuation coefficient estimation device, rain fall attenuation coefficient estimation program, and rain fall attenuation coefficient estimation system

Abstract

To enhance estimation accuracy of a rainfall attenuation coefficient regardless of a large amount of rainfall attenuation by high rainfall intensity in a partial district even in a long distance when viewing from a weather radar device, or in a partial district to the long distance when viewing from the weather radar device.SOLUTION: The present disclosure is configured to: acquire information on rainfall reflection intensity a main observation radar device M observes from points A and B present on a straight line and in a different distance when viewing from the main observation radar device M; acquire information on rainfall reflection intensity a complement observation radar device C observes from points A and B present in an almost same distance when viewing from the complement observation radar device C; and estimate a rainfall attenuation coefficient serving as an amount of rainfall attenuation per unit distance on the basis of the rainfall reflection intensity from the points A and B the main observation radar device M observes, the rainfall reflection intensity from the points A and B the complement observation radar device C observes, and a distance between the points A and B when viewing from the main observation radar device M.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a technique for estimating a rain attenuation coefficient, which is the amount of rain attenuation per unit distance. [Background technology]

[0002] Techniques for estimating the rain attenuation coefficient, which is the amount of rain attenuation per unit distance, are disclosed in Patent Documents 1 and 2. A specific example of the rain attenuation coefficient estimation process of the conventional technique is shown in FIG.

[0003] In the upper and lower sections of Figure 1, the rain reflection strength Z [dBz] observed by the weather radar equipment at a distance r [km] from the weather radar equipment is affected by the amount of rain attenuation up to the distance r [km] from the weather radar equipment (see "Before correction"), so it is necessary to remove the effect of the amount of rain attenuation up to the distance r [km] from the weather radar equipment (see "After correction").

[0004] In the upper part of Figure 1, the rain reflection strength Z [dBz] observed by the weather radar at a short distance r1 [km] from the weather radar is calculated by excluding the effect of rain attenuation K1 [dB] up to the short distance r1 [km] from the weather radar. And the rain attenuation coefficient γ1 [dB / km] at the short distance r1 [km] from the weather radar is estimated.

[0005] In the middle part of Fig. 1, the rain reflection strength Z [dBz] observed by the weather radar device at the mid-range r2 [km] from the weather radar device is calculated by excluding the effect of rain attenuation K2 [dB] up to the mid-range r2 [km] from the weather radar device. Here, rain attenuation K2 [dB] is calculated by multiplying the rain attenuation K1 [dB] estimated in the upper part of Fig. 1 and the rain attenuation K2-K1 [dB] estimated in the middle part of Fig. 1. Then, the rain attenuation coefficient γ2 [dB / km] at the mid-range r2 [km] from the weather radar device is estimated.

[0006] In the lower part of Fig. 1, the rain reflection strength Z [dBz] observed by the weather radar device at a long distance r3 [km] from the weather radar device is calculated by excluding the effect of rain attenuation K3 [dB] up to the long distance r3 [km] from the weather radar device. Here, rain attenuation K3 [dB] is calculated by multiplying rain attenuation K2 [dB] estimated in the middle part of Fig. 1 and rain attenuation K3-K2 [dB] estimated in the lower part of Fig. 1. Then, rain attenuation coefficient γ3 [dB / km] at the long distance r3 [km] from the weather radar device is estimated. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2010-197185 A [Patent Document 2] JP 2012-149920 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, in the lower part of Figure 1, the rain attenuation K3 [dB] at a long distance r3 [km] from the weather radar device is calculated by accumulating the rain attenuation K1 [dB] estimated in the upper part of Figure 1, the rain attenuation K2-K1 [dB] estimated in the middle part of Figure 1, and the rain attenuation K3-K2 [dB] estimated in the lower part of Figure 1, so the accumulation error can be large.

[0009] In the lower part of Figure 1, the rain attenuation K3 [dB] at a distance of r3 [km] from the weather radar device can also have large noise errors due to the large rain attenuation caused by high rainfall intensity in some areas up to the distance r3 [km] from the weather radar device.

[0010] Therefore, in the lower part of Figure 1, at a long distance r3 [km] from the weather radar device, the correction accuracy of the rain reflection intensity Z [dBz] observed by the weather radar device may be low, and accordingly, the estimation accuracy of the rain attenuation coefficient γ3 [dB / km] may also be low.

[0011] Therefore, in order to solve the above problem, the present disclosure aims to improve the estimation accuracy of the rain attenuation coefficient, even at long distances from the weather radar device, or regardless of large amounts of rain attenuation due to high rainfall intensity in some areas up to long distances from the weather radar device. [Means for solving the problem]

[0012] In order to solve the above problem, information on rain reflection intensity observed by the primary observation radar from two points at different distances on a straight line as seen from the primary observation radar is acquired. Then, based on the rain reflection intensity from the two points observed by the primary observation radar and the distance between the two points as seen from the primary observation radar, the rain attenuation coefficient between the two points as seen from the primary observation radar is estimated. However, the rain reflection intensity at the two points remains as an unknown quantity, not an observed value.

[0013] Therefore, information on rain reflection intensity observed by the complementary observation radar device from two points at almost the same distance from the complementary observation radar device is obtained. Then, based on the rain reflection intensity from the two points observed by the complementary observation radar device, the rain attenuation coefficient between the two points as seen by the primary observation radar device is estimated. Here, if it is assumed that the rain reflection intensity at each of the two points is the same reflection intensity as seen by the primary observation radar device and the complementary observation radar device, it is not an observation value but disappears from the unknowns. And, if it is assumed that the rain attenuation to each of the two points as seen by the complementary observation radar device is the same attenuation amount, it is not an observation value but disappears from the unknowns.

[0014] Specifically, the present disclosure provides a rain attenuation coefficient estimation device comprising: a primary observation radar rain information acquisition unit that acquires information on rain reflection intensity observed by the primary observation radar device from two points that are on a straight line and at different distances from the primary observation radar device; a complementary observation radar rain information acquisition unit that acquires information on rain reflection intensity observed by the complementary observation radar device from the two points that are at approximately the same distance from the complementary observation radar device; and a rain attenuation coefficient estimation unit that estimates a rain attenuation coefficient, which is the amount of rain attenuation per unit distance between the two points as seen from the primary observation radar device, based on the rain reflection intensity from the two points observed by the primary observation radar device, the rain reflection intensity from the two points observed by the complementary observation radar device, and the distance between the two points as seen from the primary observation radar device.

[0015] According to this configuration, the rain attenuation coefficient is not estimated based on the accumulated rain attenuation amount from the short distance to the long distance from the primary observation radar, but is estimated based on the observed value of rain reflection intensity between two points of interest from the primary observation radar. Therefore, even at a long distance from the primary observation radar, or regardless of a large rain attenuation amount due to high rain intensity in a part of the area up to a long distance from the primary observation radar, it is possible to eliminate an accumulation error or a noise error and to improve the estimation accuracy of the rain attenuation coefficient.

[0016] The present disclosure also relates to a rain attenuation coefficient estimation device, characterized in that the rain attenuation coefficient estimation unit estimates the rain reflection intensities from the two points observed by the primary observation radar equipment as Zma1 and Zmb1, the rain reflection intensities from the two points observed by the complementary observation radar equipment as Zma2 and Zmb2, the distance between the two points as seen from the primary observation radar equipment as r, and the rain attenuation coefficient γ between the two points as seen from the primary observation radar equipment as γ = {(Zma2-Zmb2)-(Zma1-Zmb1)} / r.

[0017] With this configuration, the estimation accuracy of the rain attenuation coefficient can be improved by eliminating accumulation errors or noise errors based on the rain reflection intensity from two points of interest between the two points observed by the primary observation radar equipment, the rain reflection intensity from two points observed by the complementary observation radar equipment, and the distance between the two points as seen from the primary observation radar equipment.

[0018] The present disclosure also provides a rain attenuation coefficient estimation device characterized in that the distance between the two points as seen from the primary observation radar device is short so that the distances between the two points as seen from the complementary observation radar device are approximately the same.

[0019] With this configuration, since the distance between the two points as seen by the primary observation radar equipment is short, it is possible to assume that the routes to each of the two points as seen by the complementary observation radar equipment are almost the same routes, and that the amount of rain attenuation to each of the two points as seen by the complementary observation radar equipment is the same amount of attenuation, thereby improving the estimation accuracy of the rain attenuation coefficient.

[0020] The present disclosure also provides a rain attenuation coefficient estimation device characterized in that the direction connecting the two points in a straight line as seen from the primary observation radar device is approximately perpendicular to the direction of each of the two points as seen from the complementary observation radar device, and the distances between each of the two points as seen from the complementary observation radar device are approximately the same.

[0021] With this configuration, even if the distance to each of the two points as seen by the complementary observation radar device is long, the route to each of the two points as seen by the complementary observation radar device is assumed to be approximately the same route, and the amount of rain attenuation to each of the two points as seen by the complementary observation radar device is assumed to be the same amount of attenuation, thereby improving the estimation accuracy of the rain attenuation coefficient.

[0022] The present disclosure also provides a rain attenuation coefficient estimation device characterized in that, although the direction connecting the two points in a straight line as seen from the main observation radar device and the direction of each of the two points as seen from the complementary observation radar device are not perpendicular to each other, the distances between each of the two points as seen from the complementary observation radar device are approximately the same.

[0023] With this configuration, since the distances to the two points as seen by the complementary observation radar device are short, even though the routes to the two points as seen by the complementary observation radar device are different, the amount of rain attenuation to each of the two points as seen by the complementary observation radar device can be assumed to be the same, thereby improving the estimation accuracy of the rain attenuation coefficient.

[0024] The present disclosure also relates to a rain attenuation coefficient estimation device, further comprising a rain intensity estimation unit that estimates rain intensity between the two points as seen from the main observation radar device based on the rain attenuation coefficient between the two points as seen from the main observation radar device.

[0025] With this configuration, the estimation accuracy of rain intensity can be improved based on the rain attenuation coefficient, even at long distances from the primary observation radar device, or regardless of large amounts of rain attenuation due to high rain intensity in some areas up to a long distance from the primary observation radar device.

[0026] The present disclosure also provides a rain attenuation coefficient estimation program for causing a computer to execute each processing step executed by each processing unit included in the rain attenuation coefficient estimation device described above.

[0027] According to this configuration, it is possible to provide a program having the above-described effects.

[0028] The present disclosure also provides a rain attenuation coefficient estimation system comprising the rain attenuation coefficient estimation device described above, the primary observation radar device, and the complementary observation radar device.

[0029] According to this configuration, it is possible to provide a system having the effects described above.

[0030] The above disclosed inventions can be combined to the greatest extent possible. Effect of the Invention

[0031] In this way, the present disclosure can improve the estimation accuracy of the rain attenuation coefficient, even at long distances from the weather radar device, or regardless of large amounts of rain attenuation due to high rainfall intensity in some areas up to a long distance from the weather radar device. [Brief description of the drawings]

[0032] [Figure 1] FIG. 1 is a diagram showing a specific example of a rain attenuation coefficient estimation process according to the prior art; [Diagram 2] FIG. 1 is a diagram showing an overview of a rain attenuation coefficient estimation system according to the present disclosure. [Diagram 3] 1 is a diagram illustrating a configuration of a rain attenuation coefficient estimation system according to the present disclosure. [Figure 4] FIG. 2 is a diagram showing the procedure of a rain attenuation coefficient estimation process according to the present disclosure. [Diagram 5] 1 is a diagram showing the positional relationship between a primary / complementary observation radar device of the present disclosure and an observation point. [Figure 6] 1 is a diagram showing the positional relationship between a primary / complementary observation radar device of the present disclosure and an observation point. [Figure 7] 1 is a diagram showing the positional relationship between a primary / complementary observation radar device of the present disclosure and an observation point. [Figure 8] 1 is a diagram showing the positional relationship between a primary / complementary observation radar device of the present disclosure and an observation point. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present disclosure will be described with reference to the accompanying drawings. The embodiments described below are examples of the present disclosure, and the present disclosure is not limited to the following embodiments.

[0034] (Overview of the rain attenuation coefficient estimation system of the present disclosure) An overview of the rain attenuation coefficient estimation system of the present disclosure is shown in Fig. 2. The rain attenuation coefficient estimation system S includes a primary observation radar device M, a complementary observation radar device C, and a rain attenuation coefficient estimation device R. The rain attenuation coefficient estimation device R estimates the rain attenuation coefficient, which is the amount of rain attenuation per unit distance, between points A and B in a rain area P that are on a straight line and at different distances from the primary observation radar device M.

[0035] Here, the rain attenuation coefficient estimation device R acquires information on rain reflection intensities Zma1[dBz] and Zmb1[dBz] observed by the primary observation radar device M from points A and B that are on a straight line and at different distances from the primary observation radar device M. Then, based on the rain reflection intensities Zma1[dBz] and Zmb1[dBz] from points A and B observed by the primary observation radar device M and the distance r[km] between points A and B as seen from the primary observation radar device M, the rain attenuation coefficient γ[dB / km] between points A and B as seen from the primary observation radar device M is estimated. However, the rain reflection intensities Za[dBz] and Zb[dBz] at points A and B remain as unknowns, not observed values.

[0036] Therefore, the rain attenuation coefficient estimation device R acquires information on rain reflection intensities Zma2[dBz] and Zmb2[dBz] observed by the complementary observation radar device C from points A and B that are at almost the same distance from the complementary observation radar device C. Then, based on the rain reflection intensities Zma2[dBz] and Zmb2[dBz] from points A and B observed by the complementary observation radar device C, the rain attenuation coefficient γ[dB / km] between points A and B as seen from the main observation radar device M is estimated. Here, if it is assumed that the rain reflection intensities Za[dBz] and Zb[dBz] at each point A and B are the same reflection intensities as seen from the main observation radar device M and the complementary observation radar device C (see the explanations of Figs. 3 and 4), they are not observed values ​​but disappear from the unknowns. Furthermore, if we assume that the rain attenuation Ka2 [dB] and Kb2 [dB] from points A and B as seen from the complementary observation radar device C are the same attenuation (see the explanations of Figures 5 to 7), then although they are not observed values, they disappear from the unknowns.

[0037] In this way, the rain attenuation coefficient is not estimated based on the accumulated rain attenuation amount from the short distance to the long distance as seen from the primary observation radar device M, but is estimated based on the observed value of rain reflection intensity between points A and B of interest as seen from the primary observation radar device M. Therefore, even at long distances as seen from the primary observation radar device M, or regardless of large rain attenuation amount due to high rain intensity in some areas up to the long distance as seen from the primary observation radar device M, accumulation error or noise error can be eliminated, and the estimation accuracy of the rain attenuation coefficient can be improved.

[0038] (Configuration of the rain attenuation coefficient estimation system of the present disclosure) The configuration of the rain attenuation coefficient estimation system of the present disclosure is shown in Fig. 3. The procedure of the rain attenuation coefficient estimation process of the present disclosure is shown in Fig. 4. The rain attenuation coefficient estimation device R includes a beam irradiation direction control unit 1, a primary observation radar rainfall information acquisition unit 2, a complementary observation radar rainfall information acquisition unit 3, a rain attenuation coefficient estimation unit 4, and a rainfall intensity estimation unit 5. The rain attenuation coefficient estimation device R can be realized by installing the rain attenuation coefficient estimation program shown in Fig. 4 in a computer.

[0039] The beam irradiation direction control unit 1 controls the beam irradiation directions of the primary observation radar device M and the complementary observation radar device C toward points A and B (see the description of FIG. 2) (step S1).

[0040] The primary observation radar rain information acquisition unit 2 acquires information on rain reflection intensities Zma1[dBz] and Zmb1[dBz] observed by the primary observation radar device M from points A and B, which are on a straight line and at different distances from the primary observation radar device M (step S2, formula (1)). Here, Za[dBz] and Zb[dBz] are the rain reflection intensities at points A and B, and Ka1[dB] and Kb1[dB] are the rain attenuation amounts to each of points A and B as seen from the primary observation radar device M. Zma1=Za-Ka1, Zmb1=Zb-Kb1 (1)

[0041] The complementary observation radar rainfall information acquisition unit 3 acquires information on rainfall reflection intensities Zma2[dBz] and Zmb2[dBz] observed by the complementary observation radar device C from points A and B, which are at almost the same distance from the complementary observation radar device C (step S3, formula (2)). Here, Za[dBz] and Zb[dBz] are rainfall reflection intensities at points A and B, and are assumed to be the same reflection intensities as seen by the main observation radar device M and the complementary observation radar device C, since the raindrop shape is almost spherical. Ka2[dB] and Kb2[dB] are rainfall attenuation amounts from points A and B to the complementary observation radar device C, and are assumed to be the same attenuation amounts as the attenuation path lengths are almost the same. Furthermore, ΔZ[dBz] is the observation error between the main observation radar device M and the complementary observation radar device C for rainfall with the same reflection intensity. Zma2=Za-ΔZ-Ka2, Zmb2=Zb-ΔZ-Kb2 (2)

[0042] The rain attenuation coefficient estimation unit 4 estimates the rain attenuation coefficient γ [dB / km] between points A and B as seen from the main observation radar device M based on the rain reflection intensities Zma1 [dBz] and Zmb1 [dBz] from points A and B as seen by the main observation radar device M, the rain reflection intensities Zma2 [dBz] and Zmb2 [dBz] from points A and B as seen by the complementary observation radar device C, and the distance r [km] between points A and B as seen from the main observation radar device M (step S4, equation (3)). γ={Ka1-Kb1} / r={(Za-Zma1)-(Zb-Zmb1)} / r ={(Za-Zb)-(Zma1-Zmb1)} / r ={(Zma2+ΔZ+Ka2)-(Zmb2+ΔZ+Kb2) -(Zma1-Zmb1)} / r (where Ka2=Kb2) ={(Zma2-Zmb2)-(Zma1-Zmb1)} / r (3)

[0043] The rainfall intensity estimation unit 5 estimates the rainfall intensity R [mm / h] between points A and B as seen from the main observation radar device M based on the rain attenuation coefficient γ [dB / km] between points A and B as seen from the main observation radar device M (step S5, formula (4)). Note that here, the ZR relational expression between the rain reflection intensity Z [dBz] and the rainfall intensity R [mm / h] is used, but the γ-R relational expression between the rain attenuation coefficient γ [dB / km] and the rainfall intensity R [mm / h] is used. γ = kR n , n ≒ 1, k, n depends on radar frequency (4)

[0044] In this way, between points A and B of interest as seen from the primary observation radar device M, it is possible to eliminate integration errors or noise errors and improve the estimation accuracy of the rain attenuation coefficient based on the rain reflection intensity from points A and B observed by the primary observation radar device M, the rain reflection intensity from points A and B observed by the complementary observation radar device C, and the distance between points A and B as seen from the primary observation radar device M. Furthermore, it is possible to improve the estimation accuracy of the rain intensity based on the rain attenuation coefficient, even at long distances as seen from the primary observation radar device M, or regardless of large rain attenuation due to high rain intensity in some areas up to long distances as seen from the primary observation radar device M.

[0045] (Positional relationship between the primary and complementary observation radar devices and the observation point in this disclosure) The positional relationship between the primary and complementary observation radar devices and the observation points in this disclosure is shown in Figures 5 to 7. As a first premise of this disclosure, it is assumed that the rain reflection intensities Za [dBz] and Zb [dBz] at points A and B are the same reflection intensities as seen from the primary observation radar device M and the complementary observation radar device C because the raindrop shapes are almost spherical. As a second premise of this disclosure, it is assumed that the rain attenuation amounts Ka2 [dB] and Kb2 [dB] to points A and B as seen from the complementary observation radar device C are the same attenuation amounts because the attenuation path lengths are almost the same, as follows.

[0046] In Fig. 5, the distance r [km] between points A and B as seen from the primary observation radar device M is short so that the distances between points A and B as seen from the complementary observation radar device C are approximately the same distance r' [km]. On the other hand, the distance r [km] between points A and B as seen from the primary observation radar device M is long so that the rain attenuation coefficient γ [dB / km] between points A and B as seen from the primary observation radar device M can be estimated with high accuracy. In other words, the distance r [km] between points A and B as seen from the primary observation radar device M is set taking into consideration the balance (trade-off) between the two, and is set to, for example, the distance between adjacent range bins of the primary observation radar device M.

[0047] As described above, in FIG. 5, since the distance r [km] between points A and B as seen from the primary observation radar M is short, it is possible to assume that the routes to points A and B as seen from the complementary observation radar C are almost the same, and that the rain attenuation amounts Ka2 [dB] and Kb2 [dB] to points A and B as seen from the complementary observation radar C are the same, thereby improving the estimation accuracy of the rain attenuation coefficient γ [dB / km].

[0048] In Figure 6, the direction of a straight line connecting points A and B as seen from the main observation radar device M is approximately perpendicular to the direction of each of points A and B as seen from the complementary observation radar device C, and the distance between each of points A and B as seen from the complementary observation radar device C is approximately the same distance r' [km].

[0049] In this way, in FIG. 6, even if the distance r' [km] to each of points A and B as seen from the complementary observation radar device C is long, it is assumed that the routes to each of points A and B as seen from the complementary observation radar device C are approximately the same routes, and that the rain attenuation amounts Ka2 [dB] and Kb2 [dB] to each of points A and B as seen from the complementary observation radar device C are the same attenuation amounts, thereby making it possible to improve the estimation accuracy of the rain attenuation coefficient γ [dB / km].

[0050] In Figure 7, even though the direction connecting points A and B on a straight line as seen from the primary observation radar M is not perpendicular to the direction of each of points A and B as seen from the complementary observation radar C, the distance between each of points A and B as seen from the complementary observation radar C is almost the same distance r' [km].

[0051] In this way, in Figure 7, the distance r' [km] to each of points A and B as seen from the complementary observation radar device C is a close distance within the same rainfall area, so even though the routes to each of points A and B as seen from the complementary observation radar device C are different routes, the rain attenuation amounts Ka2 [dB] and Kb2 [dB] to each of points A and B as seen from the complementary observation radar device C can be assumed to be the same attenuation amounts, and the estimation accuracy of the rain attenuation coefficient γ [dB / km] can be improved.

[0052] In Fig. 7, the distance r [km] between points A and B as seen from the primary observation radar device M may be longer than that in Fig. 6. The rain attenuation in each of "multiple sections" between points A and B as seen from the primary observation radar device M can be estimated with high accuracy, with the rain attenuation γ [dB / km] × r [km] between points A and B as seen from the primary observation radar device M being the upper limit. However, it is preferable that the direction connecting points A and B on a straight line as seen from the primary observation radar device M and the direction of each point A and B as seen from the complementary observation radar device C are not approximately on the same straight line.

[0053] In the above embodiments, the primary observation radar device M is a high-performance, high-power, long-range weather radar device or the like installed with a license by the Japan Meteorological Agency or the like, and the complementary observation radar device C is a low-performance, low-power, short-range weather radar device or the like installed without a license by a private entity or the like. As a first variation, both the primary observation radar device M and the complementary observation radar device C may be weather radar devices installed by the Japan Meteorological Agency or the like. As a second variation, both the primary observation radar device M and the complementary observation radar device C may be weather radar devices installed by a private entity or the like.

[0054] As a modification of Fig. 8, the primary observation radar M and the complementary observation radar C may switch roles of primary and complementary depending on the observation positions of the rain reflection intensity. In other words, the observation positions A and B of the rain reflection intensity are on a straight line at different distances as seen from the primary observation radar M, and are at approximately the same distance as seen from the complementary observation radar C. On the other hand, the observation positions D and E of the rain reflection intensity are on a straight line at different distances as seen from the complementary observation radar C (switched to the primary role), and are approximately the same distance as seen from the primary observation radar M (switched to the complementary role). [Industrial Applicability]

[0055] The rain attenuation coefficient estimation device, rain attenuation coefficient estimation program, and rain attenuation coefficient estimation system disclosed herein can increase the estimation accuracy of the rain attenuation coefficient even at long distances from the meteorological (primary observation) radar device, or regardless of large amounts of rain attenuation due to high rainfall intensity in some areas up to long distances from the meteorological (primary observation) radar device. [Explanation of symbols]

[0056] S: Rain attenuation coefficient estimation system M: Main observation radar device C: Complementary observation radar equipment R: Rain attenuation coefficient estimator P:Rainfall area A, B, D, E: Point 1: Beam irradiation direction control unit 2: Main observation radar rain information acquisition section 3: Complementary observation radar rainfall information acquisition section 4: Rain attenuation coefficient estimation part 5: Rainfall intensity estimation part

Claims

1. a primary observation radar rain information acquisition unit that acquires information on rain reflection intensity observed by the primary observation radar device from two points that are on a straight line and at different distances from the primary observation radar device; a complementary observation radar rain information acquisition unit that acquires information on rain reflection intensity observed by the complementary observation radar device from the two points that are at substantially the same distance from the complementary observation radar device; a rain attenuation coefficient estimation unit which estimates a rain attenuation coefficient, which is the amount of rain attenuation per unit distance between the two points as seen from the primary observation radar equipment, based on the rain reflection intensities from the two points observed by the primary observation radar equipment, the rain reflection intensities from the two points observed by the complementary observation radar equipment, and the distance between the two points as seen from the primary observation radar equipment; A rain attenuation coefficient estimation device comprising:

2. The rain attenuation coefficient estimation unit estimates the rain attenuation coefficient γ between the two points as seen from the main observation radar equipment as γ={(Zma2-Zmb2)-(Zma1-Zmb1)} / r, where Zma1 and Zmb1 are the rain reflection intensities from the two points as seen from the main observation radar equipment, Zma2 and Zmb2 are the rain reflection intensities from the two points as seen from the complementary observation radar equipment, and r is the distance between the two points as seen from the main observation radar equipment.

2. The rain attenuation coefficient estimating device according to claim 1 .

3. The distance between the two points as seen from the primary observation radar is short so that the distances between the two points as seen from the complementary observation radar are substantially the same.

3. The rain attenuation coefficient estimating device according to claim 1 or 2.

4. A direction connecting the two points on a straight line as seen from the main observation radar device and a direction of each of the two points as seen from the complementary observation radar device are approximately perpendicular to each other, and the distances between each of the two points as seen from the complementary observation radar device are approximately the same.

3. The rain attenuation coefficient estimating device according to claim 1 or 2.

5. Although the direction connecting the two points on a straight line as seen from the primary observation radar device is not perpendicular to the direction of each of the two points as seen from the complementary observation radar device, the distances between each of the two points as seen from the complementary observation radar device are substantially the same.

3. The rain attenuation coefficient estimating device according to claim 1 or 2.

6. a rain intensity estimation unit that estimates rain intensity between the two points as seen from the primary observation radar device based on a rain attenuation coefficient between the two points as seen from the primary observation radar device; The rain attenuation coefficient estimating device according to claim 1 or 2, further comprising:

7. A rain attenuation coefficient estimation program for causing a computer to execute each processing step executed by each processing unit included in the rain attenuation coefficient estimation device according to claim 1 or 2.

8. A rain attenuation coefficient estimation system comprising: the rain attenuation coefficient estimation device according to claim 1 or 2; the primary observation radar device; and the complementary observation radar device.

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