ML1RADD is the EOS Aura Microwave Limb Sounder (MLS) product containing the level 1 radiances from the digital autocorrelators. The data version is 4.2. Data coverage is from August 8, 2004 to current. Spatial coverage is near-global (-82 degrees to +82 degrees latitude), and files contain a full days worth of data (15 orbits). Users of the ML1RADD data product should read the 'A Short Guide to the Use and Interpretation of v4.2x Level 1 Data' document for additional information.The data are stored in the version 5 Hierarchical Data Format, or HDF-5. Each file contains radiances and ancillary information written as HDF-5 dataset objects (n-dimensional arrays), along with file attributes and metadata.