== P3.9	Internal TT loop working and performance== 
•	**Phase**		:	3  
•	**Status**		: 	Draft	 
•	**Category**		: 	Nighttime testing (functionality and operability) (C4)
•	**Recurrence**	: 	once at commissioning
•	**Duration**		: 	2 hours
**Description**
•	Evaluate the performance of the internal tip-tilt (TT) loop of SHARK-NIR for stars of varying brightness.
**Prerequisites**
•	Atmospheric conditions: ?
•	Authorize SHARK-NIR on the SX side.
•      Stars (of known brightness from 8mag-13mag in R band) as targets.
•	AO working.
**Procedure**
•	Run the internal TT loop after the star is acquired and the AO loop is closed. 
* Take unsaturated images of the star for a given (?) science filter before and after the internal TT loop closure in the SCICAM.
* Take data in TECCAM simultaneously. 
* Use data to estimate the improvement of the residual jitter after the TT loop is closed.
* Repeat for different star magnitudes.

**Success criteria**
•	Estimate the residual jitter after SOUL-AO is closed for a given seeing and star brightness.
* Checking the working and performance of the internal TT loop.
* Quantify and numbers to add?

**Notes**

**LBTO support**
•	SOUL-AO support

**Associated SHARK-NIR personnel**

**Date performed and by whom**