== P3.14	Star center Fourier mode images == 
 
- **Phase**		:	3  
- **Status**		: 	Draft	 
- **Category**	: 	Nighttime testing (functionality and operability) (C5) + Nighttime calibration (C6)
- **Recurrence**	: 	once after instrument installation at telescope platform
- **Duration**	: 	8 hours

**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*

**Success criteria**
- Accuracy of 3 mas (goal 1 mas) 

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

**LBTO support**
- AO support

**Date performed and by whom**