Neural Network Classification of Ice-Crystal Images Observed by an Airborne Cloud Imaging Probe

Abstract

ABSTRACT In the atmosphere, cloud particles have different shapes. The study of cloud particle shapes plays an important role in understanding cloud precipitation processes, radiative transfer, and weather modification. The image resolution and data quality of cloud probes affect the accuracy of the classification of particle shapes. To solve the occlusion of the photosensitive edge of the particle image and achieve automatic, high-precision ice-crystal classification of airborne Cloud Imaging Probe (CIP) ice-crystal images, this study uses a traditional image processing algorithm for data quality control and applies artificial intelligence algorithms to classify ice-crystal images. At present, there are mainly two types of ice-crystal classification methods, one classifies the shape of ice crystals using a pattern parameterization scheme, and the other uses an artificial intelligence network model to classify the shape. Combined with data quality control, the dataset was tested on eight models, and the TL-EfficientNet-b6 model was found to be the most accurate. Therefore, the TL-EfficientNet-b6 classifier model was used in this study, which is a newly developed convolutional neural network (CNN) based on a transfer learning method. Experimental results show that the TL-EfficientNet-b6 model can reach 100% in the single-class precision of tiny and hexagonal ice crystals, and the average precision can reach 98%. These results are more accurate than those using traditional classification methods. This method could be valuable in cloud microphysics research and weather modification.