OASIS is a collection of analysis routines and a Graphical User Interface (GUI) developed for the Cloud Imaging Probes (CIP) manufactured by Droplet Measurement Technologies, Inc. These probes utilize an illuminated one dimensional photo-diode array to create 2-d “shadow” images of cloud particles which pass through the sample area. OASIS supports both 1-bit (Mono) and 2-bit (Grayscale) CIP data formats obtained from the DMT PADS acquisition systems. OASIS has been developed to operate on multiple CPU cores/threads simultaneously, speeding up data processing and analysis.