Background information on the Nimbus 4 spacecraft and experiments is provided for potential data users as a basis for selecting, obtaining, and utilizing Nimbus 4 data in research studies. The basic spacecraft system operation and the objectives of the Nimbus 4 flight are outlined, with a detailed discussion of each of the experiments included. The format, archiving, and access to the data are also described. Finally, the contents and format of the Nimbus 4 data catalogs are described.