Disclosure of Invention
Aiming at the defects existing in the prior art, the invention provides a lamellar cloud melting layer identification method based on an airplane and a double-polarization weather radar, which comprises the steps of firstly scanning lamellar cloud by using the double-polarization weather radar to determine a target precipitation area; and then, vertical detection is carried out on a target area by using an airplane, and the ambient temperature, the particle diameter and the cloud particle image are obtained. Estimating the upper and lower boundaries of the layered cloud melting layer according to a melting layer identification algorithm MLDA and the ambient temperature detected by the aircraft; and determining the upper boundary height and the lower boundary height of the layered cloud melting layer by analyzing cloud particle images near the boundary of the melting layer and inflection points of the mass weighted average diameters of precipitation particles. The plane and the double-polarization weather radar are utilized to cooperatively detect the layered cloud melting layer, so that the recognition accuracy of the boundary of the layered cloud melting layer can be improved.
The invention provides a layered cloud melting layer identification method based on an airplane and a dual-polarization weather radar, which is characterized by comprising the following steps of;
step S1, detecting a target area by using a double-polarization weather radar, so as to determine a precipitation area in the target area; analyzing the double-polarization radar information corresponding to the precipitation area, so as to determine the boundary of the layered cloud melting layer in the precipitation area;
step S2, an airplane is instructed to vertically detect the layered cloud, so that cloud particle images above, in and below the layered cloud melting layer are obtained; analyzing the evolution characteristics of the small cloud particle image from 1km above the melting layer to the upper boundary of the melting layer, thereby determining the height of the upper boundary of the layered cloud melting layer;
step S3, the aircraft is instructed to vertically detect in the layered cloud, so that the mass weighted average diameter D of precipitation particles in the layered cloud is obtainedm And the first-order and second-order differential vertical profile thereof; analyzing the precipitation particle mass weighted average diameter Dm Is an inflection point of (1); according to Dm The evolution characteristics of the large cloud particle image from the inflection point and the lower boundary of the melting layer to 1km below the lower boundary are determined, so that the lower boundary height of the layered cloud melting layer is determined;
further, in the step S1, the target area is detected by using the dual-polarization weather radar, so that determining the precipitation area existing in the target area specifically includes:
scanning and detecting a target area by using a double-polarization weather radar so as to obtain double-polarization radar information corresponding to the target area;
extracting cloud layer reflectivity information corresponding to a target area from the dual-polarization radar information, and determining a precipitation area according to the cloud layer reflectivity information;
further, in the step S1, analyzing the dual-polarized radar information corresponding to the precipitation area, so as to determine the boundary of the layered cloud melting layer in the precipitation area specifically includes:
processing the double-polarization radar parameters corresponding to the precipitation area by using a melting layer identification algorithm MLDA; estimating the upper boundary and the lower boundary of the layered cloud melting layer in the water-reducing area by using a melting layer identification algorithm MLDA output result and the aircraft detected ambient temperature;
further, in the step S2, the plane is instructed to perform vertical detection on the layered cloud, so as to obtain cloud particle images above, in and below the layered cloud melting layer, specifically including:
the aircraft is instructed to vertically detect the layered cloud, so that the aircraft detects the areas above, in and below the melting layer of the estimated layered cloud, and cloud particle images above, in and below the melting layer of the layered cloud are obtained;
further, in the step S2, analyzing the evolution characteristics of the small cloud particle image from 1km above the melting layer to the upper boundary of the melting layer, so as to determine the height of the upper boundary of the layered cloud melting layer specifically includes:
identifying and obtaining the shape and phase state information of ice particles from a small cloud particle image from 1km above the melting layer to the upper boundary of the melting layer;
determining evolution characteristics of the shape and the phase state of the ice particles 1km above the layered cloud melting layer and reaching the upper boundary of the melting layer according to the shape and the phase state information of the ice particles; extracting turning points of the shape and the phase state of the ice particles according to the evolution characteristics of the shape and the phase state of the ice particles; then taking the height corresponding to the turning point as the upper boundary height of the layered cloud melting layer;
further, in said step S3,
an airplane is instructed to vertically detect the layered cloud melting layer, so that a particle image of the layered cloud melting layer and vertical distribution characteristics of cloud micro physical quantity are obtained; analyzing the vertical distribution characteristics of the particle image and the cloud micro physical quantity; and determining the height of the lower boundary of the melting layer according to the evolution characteristic of the large cloud particle image along with the height and the vertical distribution characteristic of the cloud micro physical quantity.
Compared with the prior art, the method for identifying the layered cloud melting layer based on the plane and the double-polarization weather radar comprises the steps of firstly scanning the layered cloud by using the double-polarization weather radar to determine a target precipitation area; and then, performing vertical detection on a target area by using an airplane to obtain an environment temperature, a particle diameter and a cloud particle image. Estimating to obtain the upper boundary of the layered cloud melting layer according to the MLDA processing result of the melting layer identification algorithm and the environmental temperature; determining the height of the upper boundary of the layered cloud melting layer by analyzing the evolution characteristics of the particle image near the upper boundary of the melting layer; and determining the height of the lower boundary of the layered cloud melting layer by analyzing the evolution characteristics of the particle image near the lower boundary of the melting layer and the inflection point of the weight average diameter of the mass of the precipitation particles. The plane and the double-polarization weather radar are utilized to cooperatively detect the layered cloud melting layer, so that the recognition accuracy of the boundary of the layered cloud melting layer can be improved.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims thereof as well as the appended drawings.
The technical scheme of the invention is further described in detail through the drawings and the embodiments.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Referring to fig. 1, a flow chart of a method for identifying a layered cloud melting layer based on an aircraft and a dual-polarization weather radar according to an embodiment of the present invention is shown. The layered cloud melting layer identification method based on the plane and the double-polarization weather radar comprises the following steps of;
step S1, detecting a target area by using a double-polarization weather radar, so as to determine a precipitation area in the target area; analyzing the double-polarization radar information corresponding to the precipitation area, so as to determine the boundary of the layered cloud melting layer in the precipitation area;
step S2, an airplane is instructed to vertically detect the layered cloud, so that cloud particle images above a melting layer, in the melting layer and below the melting layer of the layered cloud are obtained; analyzing the evolution characteristics of the small cloud particle image from 1km above the melting layer to the upper boundary of the melting layer, thereby determining the height of the upper boundary of the layered cloud melting layer;
step S3, the aircraft is instructed to vertically detect in the layered cloud, so as to obtain the mass weighted average diameter D of precipitation particles in the layered cloudm And the first-order and second-order differential vertical profile thereof; analysis of the precipitation particles mass weighted average diameter Dm Is an inflection point of (1); according to Dm And determining the height of the lower boundary of the layered cloud melting layer by turning points and the evolution characteristics of the cloud particle image from the lower boundary of the melting layer to 1km below the lower boundary.
The beneficial effects of the technical scheme are as follows: the method for identifying the layered cloud melting layer based on the plane and the double-polarization weather radar comprises the steps of firstly detecting a target area by using the double-polarization weather radar, and estimating the upper boundary and the lower boundary of the layered cloud melting layer by combining a melting layer identification algorithm; and vertical detection is carried out on the target area by using the airplane, so that a particle image and a particle mass weighted average diameter in the cloud are obtained. The upper and lower boundary heights of the layered cloud melt layer are determined by analyzing the vertical distribution characteristics of the particle image and the particle mass weighted average diameter. The method has the advantages that the advantages of radar remote sensing and airplane field detection are taken into consideration by utilizing the cooperative detection means of the airplane and the double-polarization weather radar for the layered cloud melting layer, and the recognition accuracy of the layered cloud melting layer can be improved.
Preferably, in this step S1, the target area is detected by using a dual polarized weather radar, so that determining the precipitation area existing in the target area specifically includes:
scanning and detecting a target area by using a double-polarization weather radar so as to obtain double-polarization radar information corresponding to the target area;
and extracting cloud layer reflectivity information corresponding to the target area from the dual-polarization radar information, and determining a precipitation area according to the cloud layer reflectivity information.
The beneficial effects of the technical scheme are as follows: the radar scanning detection is carried out on the target area through the double-polarization weather radar, so that a double-polarization radar image corresponding to the target area can be obtained, the double-polarization radar image contains cloud layer reflectivity information of a polarization state in the target area, and a precipitation area existing in the target area can be determined through extracting and analyzing the cloud layer reflectivity information. Because the cloud layer reflectivity of the precipitation cloud layer existing in the precipitation area is obviously different from the cloud layer reflectivity of other non-precipitation areas, the existing position of the precipitation area can be rapidly and accurately determined based on the difference, and the method belongs to a precipitation area determination mode commonly used in the field, and the specific determination process is not detailed.
Preferably, in the step S1, analyzing the dual-polarized radar information corresponding to the precipitation area, so as to determine the boundary of the layered cloud melting layer in the precipitation area specifically includes:
processing the double-polarization radar parameters corresponding to the precipitation area by using a melting layer identification algorithm MLDA; and (3) estimating and obtaining the upper boundary and the lower boundary of the layered cloud melting layer in the water-reducing area by using the output result of the melting layer identification algorithm MLDA and the detected ambient temperature of the airplane.
The beneficial effects of the technical scheme are as follows: and after determining the corresponding precipitation area, acquiring double-polarization radar information corresponding to the precipitation area, and processing the double-polarization radar information by adopting a thawing layer identification algorithm MLDA. According to the output result of the fusion layer identification algorithm MLDA and the detected ambient temperature of the airplane, the upper boundary and the lower boundary of the layered cloud fusion layer in the water-reducing area can be estimated, wherein the adoption of the fusion layer identification algorithm MLDA for double-polarization radar information processing belongs to the conventional technical means in the field, and detailed description is omitted here.
Preferably, in the step S2, the plane is instructed to perform vertical detection on the layered cloud, so as to obtain cloud particle images above, in and below the layered cloud melting layer specifically includes:
and indicating the plane to perform vertical detection on the layered cloud so as to enable the plane to detect in the areas above, in and below the melting layer of the estimated layered cloud, thereby obtaining cloud particle images above, in and below the melting layer of the layered cloud.
The beneficial effects of the technical scheme are as follows: when the upper boundary and the lower boundary of the layered cloud melting layer are estimated, the aircraft is instructed to detect three areas, namely, a region 1km above the upper boundary of the layered cloud melting layer, a region 1km in the melting layer and a region 1km below the lower boundary of the melting layer, by using the carried two-dimensional stereo light array probe 2DS and the cloud particle high-definition imager CPI, so that cloud particle images above the layered cloud melting layer, in the melting layer and below the melting layer are obtained.
Preferably, in the step S2, analyzing the evolution characteristics of the small cloud particle image from 1km above the melting layer to the upper boundary of the melting layer, so as to determine the height of the upper boundary of the layered cloud melting layer specifically includes:
identifying and obtaining the shape and phase state information of ice particles from a small cloud particle image from 1km above the melting layer to the upper boundary of the melting layer;
determining the evolution characteristics of the shape and the phase state of the ice particles 1km above the layered cloud melting layer to the upper boundary of the melting layer according to the shape and the phase state information of the ice particles; extracting turning points of the shape and the phase state of the ice particles according to the evolution characteristics of the shape and the phase state of the ice particles; and taking the height corresponding to the turning point as the upper boundary height of the layered cloud melting layer.
The beneficial effects of the technical scheme are as follows: the ice crystal shape is mainly related to temperature, humidity, etc. During the ice crystal falling process, as the ambient temperature gradually increases, the ice crystal begins to melt and changes shape. As the temperature increases further, some small scale ice crystals fuse into spherical droplets. The height corresponding to the temperature can determine the upper boundary height of the layered cloud melting layer.
Preferably, in the step S2, according to the shape and phase state information of the ice particles, determining the evolution characteristics of the shape and phase state of the ice particles from 1km above the layered cloud melting layer to the upper boundary of the melting layer; and then according to the evolution characteristics of the shape and the phase state of the ice particles, determining the upper boundary height of the layered cloud melting layer specifically comprises the following steps:
according to the ice particle shape and phase state information and the corresponding height of the aircraft vertically detected in the area near the upper boundary of the layered cloud melting layer, determining the evolution characteristics of the ice particle shape and phase state of the area near the upper boundary along with the height;
and extracting turning points of the shape and the phase of the ice particles from evolution characteristics of the shape and the phase of the ice particles, and taking the height corresponding to the turning points as the upper boundary height of the layered cloud melting layer.
The beneficial effects of the technical scheme are as follows: as the ambient temperature rises, the edges and corners of the ice crystal appearance above the melting layer are clear, the ice crystal appearance near the upper boundary of the melting layer is round, and small-scale melting spherical ice particles begin to appear. And according to the height corresponding to the change characteristics of the shape and the phase state of the ice particles, the upper boundary height of the layered cloud melting layer can be accurately judged.
Preferably, in the step S3, the aircraft is instructed to perform vertical detection on the layer cloud melting layer, thereby obtaining a precipitation particle mass weighted average diameter D of the layer cloudm The method specifically comprises the following steps:
directing an aircraft to vertically detect the layered cloud so as to obtain a particle image and a particle spectrum of the layered cloud melting layer; the precipitation particle mass weighted average diameter D of the layered cloud melting layer is obtained through calculationm . Analyzing the particle image to obtain particle shape and phase state information corresponding to the area below the layered cloud melting layer, and further determining evolution characteristics of the shape and phase state of the large cloud particles; and then according to the shape of the large cloud particles and the evolution characteristics of the phase state. Finally, the average diameter D is weighted by the mass of precipitation particlesm And (3) calculating to obtain the lower boundary height of the layered cloud melting layer according to the inflection point of the cloud particle shape and the evolution characteristics of the phase state.
The following is a specific application example of the melting layer identification method of the technical airplane and the polarized weather radar:
taking the process of detecting the first layered cloud precipitation of the middle and the south of the Hebei province by using an aerial King 350 artificial precipitation plane and an X-band dual-polarization weather radar in the weather center of the Hebei province as an example, the implementation process of the algorithm is shown. The scheme adopted is as follows:
(1) and determining a precipitation area by radar scanning. And according to the radar estimation result, performing vertical detection by using the aircraft. And estimating the upper boundary and the lower boundary of the melting layer according to the melting layer identification algorithm MLDA and the ambient temperature observed by the aircraft.
(2) And vertically detecting the layered cloud by using a two-dimensional stereo optical array probe 2DS and a cloud particle high-definition imager CPI carried by the airplane to obtain a cloud particle image. And analyzing the shape and the phase evolution characteristics of the ice particles near the upper boundary of the melting layer. The ice crystal appearance edges and corners above the melting layer are clear, the upper boundary appearance of the melting layer is fuzzy, and small-scale spherical and ellipsoidal liquid drops appear. And determining the height of the upper boundary of the melting layer according to the evolution characteristics of the shape and the phase state of the small cloud particles near the upper boundary of the melting layer.
(3) And detecting and acquiring a precipitation particle spectrum by using a high-volume precipitation spectrometer HVPS carried by the aircraft. Calculation of precipitation particle mass weighted average diameter D from particle spectram Obtaining Dm And the first and second differential vertical profiles thereof. Searching D from bottom to top within 1km from the lower boundary to the lower boundary of the melting layerm The second order difference value exceeds 0.5X104 mm km-2 Corresponding height, and D within + -150 m of the heightm The first order differential value exceeds 100mm km-1 Point D of (2)m Inflection point. And analyzing the evolution characteristics of the cloud particle image near the lower boundary of the melting layer. According to Dm And the inflection point and the characteristic that the lower boundary of the melting layer is gradually and gradually melted into spherical liquid drops, and determining the height of the lower boundary of the melting layer.
Referring to fig. 2, particle images corresponding to different parts of a layered cloud melt layer in the method for identifying the layered cloud melt layer based on the plane and the dual-polarization weather radar provided by the invention are shown. The particle image corresponding to fig. 2 directly reflects the particle images of three different partial areas of the upper boundary of the melt layer, the middle of the melt layer and the lower boundary of the melt layer of the layered cloud melt layer. The height corresponding to the upper boundary and the lower boundary of the melting layer can be accurately obtained by analyzing the particle image, and repeated tiredness is not made here.
Referring to fig. 3, a schematic diagram of a vertical profile of aircraft detection data in a layered cloud melt layer identification method based on an aircraft and a dual-polarization weather radar is provided. The detection data schematic diagram sequentially comprises a layered cloud environment temperature vertical profile, a precipitation particle mass weighted average diameter vertical profile and a precipitation particle mass weighted average diameter D from left to rightm Is a first order differential vertical profile of (D) and precipitation particle mass weighted average diameter Dm Is a second order differential vertical profile of (c). And black dotted lines in the figure represent the upper and lower boundaries of the layered cloud melt layer, respectively.
As can be seen from the content of the above embodiment, the method for identifying the layered cloud melting layer based on the plane and the dual-polarization weather radar firstly scans the layered cloud by using the dual-polarization weather radar to determine a target precipitation area; and then, performing vertical detection on a target area by using an airplane to obtain an environment temperature, a particle diameter and a cloud particle image. Estimating to obtain the upper boundary of the layered cloud melting layer according to the MLDA processing result of the melting layer identification algorithm and the environmental temperature; determining the height of the upper boundary of the layered cloud melting layer by analyzing the evolution characteristics of the particle image near the upper boundary of the melting layer; and determining the height of the lower boundary of the layered cloud melting layer by analyzing the evolution characteristics of the particle image near the lower boundary of the melting layer and the inflection point of the weight average diameter of the mass of the precipitation particles. The plane and the double-polarization weather radar are utilized to cooperatively detect the layered cloud melting layer, so that the recognition accuracy of the boundary of the layered cloud melting layer can be improved.
It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.