SDC2 Instrument flat field, detector linearity and bad pixels

• Phase : Any
• Status : Draft
• Category : Daytime calibration (C3)
• Recurrence : every day, with setup on request.
• Duration : 20 minutes per configuration (this duration is valid only during regular operations, i.e., after commissioning)

Description

• Instrument flat field, detector linearity, and bad pixels.

Prerequisites

Procedure

• Use the calibration flat-field source.
• This calibration is performed illuminating the detector uniformly using the instrument FF lamp, for each filter.
• It is expected that the detector FF depends on filters, the final accumulated charge in the pixels. Thus, a series of exposures will be taken at different count levels (realized via ND filters and/or DIT) for each filter setup. In this case, the template takes the background frames automatically. Comparing different count rates at constant DIT will also yield a linearity map of the detector.

Templates

• SHARKNIR_gen_cal_InstrumentFlatField (not released)

Success criteria

• 95% luminous uniformity at a large scale.
• 99% luminous uniformity at pixel-to-pixel scale 10-2.
• Large scales filtered out, only a small detector scale will remain. Effect of the large-scale flat field on DBI (rescaling in flux & wavelength) has negligible impact on DBI performances.

Notes

• Same as activity 7.9 in AD4

LBTO support

Date performed and by whom