Gust front automatic recognition method based on Doppler weather radar data

Abstract

The invention discloses a gust front automatic recognition method based on Doppler weather radar data, and the method comprises the following steps: 1), extracting a weak narrow band echo suspected area according to the radar performance characteristics of gust front through employing a local binaryzation algorithm; 2), carrying out the segmentation, connection and screening of the weak narrow band echo suspected area, and obtaining a skeleton image corresponding to a weak ridge-shaped belt; 3), obtaining an optical flow field through two low-pitching-angle radar images at a current moment and a former moment, supposing the matched skeletons at the former and latter moments in the skeleton images corresponding to the weak ridge-shaped belt obtained at step 2) as the suspected gust front, and recognizing the gust front according to the relation between the position and speed of the suspected gust front and the position and speed of a windstorm cell and the relation between the direction and speed of the suspected gust front. The method achieves the automatic detection of the gust front, achieves the timely early warning of disasters, and reduces the economic loss and casualty. Moreover, the validity of the method is verified.

Description

technical field [0001] The invention relates to the field of meteorology, in particular to an automatic identification method of gust front based on Doppler weather radar data. Background technique [0002] Weather radar is one of the main tools for monitoring and early warning of severe convective weather. Weather radar emits electromagnetic waves in the form of pulses. When the electromagnetic waves encounter precipitation materials (snowflakes, raindrops and hail, etc.), most of the energy continues to move forward, while a small part of the energy is scattered in all directions by the precipitation material, and the energy scattered back is received by the radar. [0003] In the mature stage of the convective cell, the cold downdraft, as a cold air, expands outward at the bottom layer near the ground, and merges with the warm and humid airflow in front of the cell to form a front. This phenomenon is reflected in the radar reflectivity map. Usually, a weak ridge-shaped a...

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Problems solved by technology

literature [3] The method cannot be used when there is an invalid velocity area in the velocity field data; in the reflectivity intensity field, the two-way gradient method limits the distance between the narrowband echo and the parent echo

So far, in the literature on gust front detection, there is no solution to the overlapping phenomenon of gust front and other weak narrow-band echo collisions, and there is no solution to the fracture phenomenon in the gust front detection.

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