17.11

Cycle 17 Calibration Plan

The STIS Cycle 17 calibration plan includes the usual routine calibration and monitoring observations performed in previous Cycles; however, because of the long gap in STIS operations, and changes in STIS usage, the emphasis on some activities have changed:

•	Programs to derive new pixel-to-pixel flat fields for both the MAMA (programs 11861 and 11862) and CCD (programs 11852 and 11853) detectors were a high priority for early in Cycle 17.

•	New flux calibrations for all STIS echelle central wavelength settings have also been included early in the cycle, in order to measure changes in the echelle blaze function (program 11866).

•	Special calibration programs to improve the cross-calibration between STIS, COS, and other space-based instrumentation (programs 11865 and 11999) were also executed.

•	New supplemental Cycle 17 calibration programs were added to follow up on the results of earlier SMOV4 and Cycle 17 calibration observations.Specifically, program 12078: to verify of the adjustment of two STIS MSM positions and 12079: to study the calibration lamp ratios at all wavelengths.

•	Observations were added as part of the Cycle 17 supplemental calibration plan to programs 11861, 11857, and 11860 to improve the characterization of the FUV-MAMA flat fields, the MAMA dark rate, and the echelle time-dependent sensitivity.