== P3.13 	Distortion map == 
 
- **Phase**		:	3  
- **Status**		: 	Draft	 
- **Category**	: 	Nighttime testing (functionality and operability) (C5) + Nighttime calibration (C6)
- **Recurrence**	: 	once every week starting from commissioning + on request.
- **Duration**	: 	4 hours

**Description**
- Determine distortion map of science frame. Monitor distortion coefficient with time (weekly calibration) and measure the precise distortion of a given observation in any setup, if requested. 

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

**Procedure**
- Observe a dense field (e.g., a globular cluster) with accurate HST astrometry and a guide star bright enough (mag F860W < 11).

**Templates**

**Success criteria**
- Better than 1 mas over FoV. 

**Notes**
- Same as activity 9.6 in AD4

**LBTO support**
- AO support

**Date performed and by whom**