P2.9 Star center Fourier mode images

• Phase : 2
• Status : Draft
• Category : Daytime testing (functionality and operability) (C3)
• Recurrence : once after instrument installation at telescope platform
• Duration : 1 day

Description

• This calibration is performed to calibrate the center of the target star (hidden by the coronagraph) in order to provide a reference input for frame derotation to be performed in post-processing.

Prerequisites

Procedure

• TBW+TBC
• Offset of the ASM generating multiple satellite spots in the focal plane + AO closed-loop + coronagraph
• The required specifications of the corresponding image are the presence of at least 4 satellite spots placed symmetrically with respect to the star, at separation within 5 and 15 lambda/D, with FWHM < 45 mas and separation precision < 6 mas.
• Either KL#62 or KL#119 is applied to the ASM on target acquisition to generate the satellite spots. Find the centroids of the spots and fit a circle to them. The center of the circle is the extrapolated star position behind the coronagraph.

Templates

• SHARKNIR_gen_cal_StarCenter (not released)

Success criteria

• Accuracy < 10 mas (goal 5 mas)

Notes

• Same as activity 7.8 in AD4

LBTO support

• Authorize SHARK-NIR on the SX side.
• AO support

Date performed and by whom