The ISIS file format is a specialized data structure primarily used by the United States Geological Survey (USGS) for the processing and analysis of planetary image data. It is the core format for the Integrated Software for Imagers and Spectrometers (ISIS) software suite, which is widely utilized by planetary scientists to calibrate, map, and analyze data returned from space missions such as those by NASA and ESA. The format is designed to handle multi-dimensional data cubes, which include not only the raw pixel values from sensors but also extensive metadata regarding the spacecraft's orientation, camera geometry, and planetary coordinates. This allows researchers to perform complex photogrammetric tasks, such as orthorectification and mosaicking, ensuring that images taken from different angles or times can be accurately aligned to a planetary surface model. Because it stores complex spatial and spectral information, it is significantly more robust than standard image formats like JPEG or PNG, which lack the necessary geodetic metadata required for scientific planetary research.