Automatic hail identification method based on radar image spatial mapping

An automatic hail identification method based on radar image spatial mapping, comprising the following steps:

• S1:
• obtaining a base reflectivity radar image, wherein the base reflectivity radar image comprises radar information parameters and a radar echo image;
• S2:
• identifying text information, digital parameters and color scales from the radar information parameters, grading radar echoes using intensity values represented by different colors, and detecting radar center coordinates from the radar echo image;
• S3:
• performing spatial mapping on radar echo information through a planar projection algorithm by using the radar center coordinates and the identified text information and digital parameters, and establishing a dictionary for radar echo intensity in a new radar image space;
• S4:
• after expanding the dictionary in a rectangular coordinate system of a screen, transforming V-shaped notch and three-body scatter spike (TBSS) characteristics behind an original radar echo area into a standard rectangle and a triangle behind a echo in the new radar image space;
• S5:
• establishing an identification for the standard rectangle and the triangle behind the echo in the new radar image space, filtering out noise interference, and analyzing the standard rectangle and the triangle outside of a echo by graphic fitting, wherein if the standard rectangle behind the echo in the new radar image space is successfully fitted, there is a V-shaped notch in the original radar image, and there is a second hail;
• if the triangle behind the echo in the new radar image space is successfully fitted, there is TBSS in the original radar image, and there is first hail;
• otherwise, there is no hail;
• and
• S6:
• marking the V-shaped notch or the TBSS if any in the original radar image, calculating a position where hail occurs using the identified text information and digital parameters, outputting an identification result as first hail or second hail, and the position where hail occurs, otherwise, outputting no hail.