A new low-cost three-dimensional precipitation particle imager (3D-PPI ² ): design and experiment

Abstract This study introduces the new low-cost generation of three-dimensional precipitation particle imager version 2 (3D-PPI 2 ), a novel device designed to observe the solid precipitation particles. The 3D-PPI 2 is equipped with five high-resolution cameras positioned at various angles to capture detailed images of the particles. Compared to its predecessor, this version increases the number of cameras and enhances the ability to capture side information about the particles. It employs non-telecentric lenses, which significantly decrease both the size and construction cost of the instrument. Considering the characteristics of non-telecentric lenses, this study designed a calibration experiment and a data preprocessing algorithm. Field observations were conducted in Yantai, China, during the winter of 2024–2025. The shape and texture features of the obtained data were analyzed. The results demonstrate the effectiveness of the 3D-PPI 2 in capturing detailed information about solid precipitation particles, providing valuable data for the study of cloud and precipitation physics.