Stage II processing units: * environment, environment variables, file names, paths and types. * mask, define the mask pattern. * detector, physical detector parameters, calibration data. * instrument create the instrument data file. * cdi, assemble a detector image from an eventfile. * correlate, reconstruct celestial image. * iros, reconstruct celestial image, identify sources. * simulate, compute a mean detector image, given a sourcelist. * lcv, compute lightcurve and spectrum for selected sky positions. * eci, restore X-ray data in reduced sky .res image. * wop, arithmatic operations on FITS images.