In traditional methods, the radar echo‐top (ET) height is in fact calculated from radar signals at the same slant range but different horizontal locations, which may result in deviations. To address this problem, a new method for calculating ET height has been presented in this article, involving a three‐step process: first, the raw 3D polar coordinate radar data (comprising elevation angle, slant range, and azimuth angle) is transformed into a new 3D polar coordinate system (incorporating elevation angle, horizontal distance, and azimuth angle). Subsequently, the maximum elevation angle corresponding to a reflectivity of 18 dBZ at specific horizontal locations is identified through linear interpolation. Finally, the ET height is computed utilizing the radar beam height formula. Compared with traditional methods, the new method adds the process of coordinate conversion of radar data, which ensures that the radar signals at different elevation angles used to calculate ET height are from the same horizontal location. Comparative analyses based on China New Generation Weather Radar/SA (CINRAD/SA) data at Nanchang (NC) and Jingdezhen (JDZ) during June–July 2020 reveal that the difference between ET heights obtained from the new and traditional methods can exceed 2 km, and the ET height derived from the new method exhibits enhanced association with observed precipitation. Furthermore, the ET heights from both methods are introduced into a Gate Recurrent Unit (GRU) Neural Network for radar quantitative precipitation estimation (RQPE). The results indicate that the difference between RQPEs generated from the two calculated ET heights can occasionally exceed 10 mm, with the RQPE based on the new method’s ET heights exhibiting closer alignment with observed precipitation. This improved physical consistency underscores the potential of the new method of ET height for improving precipitation estimation.
Zhu et al. (Thu,) studied this question.