H. He, J. McDowell, M.Conroy
SAO
We describe the coordinate transformation library for AXAF data analysis. The library handles transformations between celestial coordinates and instrumental (mirror, focal plane, detector pixel) coordinate systems. The need for careful transformations is driven by the telescope and the accuracy of the detectors and the attitude determination system. Some of the detectors consist of non-planar elements. Coordinate transform calculations are driven by a set of parameter interface files which store experimental and scientific calibration parameters, and use a set of generic matrix transformation routines for maximum flexibility. The code is written in C and uses the SAO IRAF-compatible parameter interface.