== [[span(style=color: green, **P3.14	Star center Fourier mode images** )]]== 
 
- **Phase**		:	3  
- **Status**		: 	[[span(style=color: green, **COMPLETE** )]][[span(style=color: blue, **, checks at fainter magnitude stars to be performed later with low priority** )]]	  	 
- **Category**	: 	Nighttime testing (functionality and operability) (C5) + Nighttime calibration (C6)
- **Recurrence**	: 	once after instrument installation at telescope platform
- **Duration**	: 	1 hour

**Description**
- This calibration is performed to calibrate the target star center to the detector in order to provide a reference input for frame derotation and quadrant combination. 

**Prerequisites**
- Authorize SHARK-NIR on the SX side.
- Atmospheric conditions: AO working conditions.
- Bad pixel map, Dark 

**Procedure**
- DM produce a pattern offset with four spots symmetric with respect to the star + AO closed-loop + coronagraph
- The corresponding image's required specifications are a grid of at least 2x2 regularly spaced focal plane image peaks within 5 and 15 lambda/D with FWHM < 45 mas and separation precision < 6 mas.
- DM offset applied on target acquisition to produce a waffle image. Find the center of the four first-order diffraction peaks (cross geometry) to deduce the pixel corresponding to the center field.

**Templates**
- There is no template as of now (12 Oct 2023). The Fourier modes are injected by the LBT ASM experts [Guido and Xang-yu]. Currently,  they are working to make the procedure automated.


**Success criteria**
- Accuracy of 3 mas (goal 1 mas) 
- A report of the activity performed during daytime tests on 15, 20, and 21 of December 2022 using SHARK-NIR coupled with the M2 adaptive secondary mirror (ASM) of LBT can be found in this ​link
- Details of the activity done on-sky and a summary can be found in the minutes of the run.

**Notes**
- Same as activity 7.8 in AD4

**LBTO support**
- AO support

**Date performed and by whom**