HARP is a toolkit for reading, processing and inter-comparing satellite remote sensing data, model data, in-situ data, and ground based remote sensing data. The toolkit is composed of a set of command line tools and a C library of analysis functions.
The main goal of HARP is to assist in the inter-comparison of data sets. By appropriately chaining calls to HARP command line tools one can pre-process data sets such that two datasets that need to be compared end up having the same temporal/spatial grid, same data format/structure, and same physical unit. At the end of the toolchain you will have a set of data files that can be directly compared in e.g. Python, IDL or MATLAB.
In order for the HARP command line tools to handle each others output the toolkit uses its own data format conventions for intermediate files. The use of this harmonized formatting means that satellite products need to be converted first to HARP compliant files. Once in this format, further processing can be performed. HARP already contains builtin support for a wide range of atmospheric data products.