The purpose of this document is to describe the Cloud Absorption Radiometer (CAR) Instrument, methods used in the CAR Hierarchical Data Format (HDF) data processing, the structure and format of the CAR HDF data files, and methods for accessing the data. Examples of CAR applications and their results are also presented. The CAR instrument is a multiwavelength scanning radiometer that measures the angular distributions of scattered radiation. Li, Jason Y. and Arnold, G. Thomas and Meyer, Howard G. and Tsay, Si-Chee and King, Michael D. Goddard Space Flight Center NASA Order C-1269-25...