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) to provide a reference input for frame derotation in post-processing.

Prerequisites

Procedure

• Apply ASM Fourier modes to generate multiple satellite spots in the focal plane + AO closed-loop + coronagraph.
• The required specifications are the presence of at least four satellite spots placed symmetrically to the star, at separation within 5 and 15 lambda/D, with FWHM < 45 mas and separation precision < 6 mas.
• 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.
• The detailed sequence of tests is described in ​https://docs.google.com/document/d/18j3rBLl6Z4qZXMq1UN-AXKVImgvY4kB7F6lc0gne8m4/edit

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 (Juan Carlos, Xianyu, Guido)

Date performed and by whom November 21st, Luca, Elena, Daniele, Davide R., Jacopo