The OGIP caldb classifies files as `Primary Calibration Files', `Basic Calibration Files' and `Calibration Product Files' (PCFs, BCFs & CPFs respectively; see also CAL/GEN/91-001, available on-line as postscript and html versions). PCFs are 'raw' ground and in-orbit calibration datasets not of immediate interest to most users as they are not directly required for (all but the most specialized) scientific data analysis tasks. These dataset are not considered here. BCFs contain the lowest level calibration datasets potentially required by downstrem software, and can be considered the `atomic units' of the instrument calibration. CPFs contain `convolutions' of the information stored within BCFs customized for a specific analysis task and/or scientific observation.
All BCF & CPF calibration files are organized using the scheme
/cpfsub-directories is made in most cases. Non-instrument specific calibration datasets, including general spacecraft housekeeping information etc, can be found in the