| 1 | == P3.21 Star center == |
| 2 | • **Phase** : 3 |
| 3 | • **Status** : Draft |
| 4 | • **Category** : Nighttime calibration (C5) |
| 5 | • **Recurrence** : on every target, starting from commissioning. |
| 6 | • **Duration** : 20 minutes |
| 7 | **Description** |
| 8 | • This calibration is performed to calibrate the target star center with respect to the detector in order to provide a reference input for frame derotation and quadrant combination. |
| 9 | **Prerequisites** |
| 10 | • Authorize SHARK-NIR on the SX side. |
| 11 | • Atmospheric conditions: AO working conditions. |
| 12 | • Bad pixel map, Dark |
| 13 | **Procedure** |
| 14 | • DM produce a pattern offset with four spots symmetric with respect to the star + AO closed-loop + coronagraph |
| 15 | • The required specifications of the corresponding image 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. |
| 16 | • 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. |
| 17 | **Success criteria** |
| 18 | • Accuracy of 3 mas (goal 1 mas) |
| 19 | **Notes** |
| 20 | • Same as activity 7.8 in AD4 |
| 21 | **LBTO support** |
| 22 | • Support from LBTI/LBTO? |
| 23 | **Associated SHARK-NIR personnel** |
| 24 | • JF, LM, MdP |
| 25 | **Date performed and by whom** |