This chapter is concerned with the transformation of the Astro-D data formats from telemetry to more readily accessible formats. The first of these transformations is the conversion of the original data as sent from Japan into FITS format. This transformation, which involves no loss of information, will allow access to the raw data in a standard, self-defining file structure enabling present and future investigators to analyze their data without the need to be familiar with the Astro-D-specific data structures. Further transformations use the scientific and housekeeping data to filter and select subsets for analysis. The processing system itself is described in the next chapter, and illustrated by the flow charts in Figs. 1-3.