== 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**