Since each decontamination procedure changes the structure of the flat fields and assembling a new flat field calibration from observations of the sunlit earth requires many observations, internal calibration lamp exposures for a limited set of filters have been obtained twice per month since late December 1991. Some other internal lamp exposures have also been obtained as part of the calibration program. This lamp is not bright and therefore only broadband, longer wavelength internal flat fields can be obtained. The 2876 proposal for Cycle 1 calibration internal flats is executed approximately every two weeks. The details on these intflats have been summarized in Table 1.
All tables specify the filter, camera, exposure time, and date of each observation.
Due to the different reflectivity characteristics of the two shutter blades, the shutter in use is listed as well. In addition to the variations in the overall streak patterns, blade A exhibits obvious internal reflections in group 4 while blade B has these reflections in group 2.