P2.6 Tip-Tilt internal fast loop test with ASM turbulence

• Phase : 2
• Status : Draft
• Category : Daytime testing (functionality and operability) (C3)
• Recurrence : after instrument installation at telescope platform
• Duration : 1/2 day

Description

• To verify the SHARK-NIR internal fast tip-tilt loop (using CRED2 and SHARK-NIR ALPAO DM) using the ARGOS light source (only at zenith) for various seeing conditions (0.5", 0.8") simulated at the ASM. This test will verify if the correction of the fast tip-tilt loop is affected by the residual turbulence for star at different magnitudes.
• Before or after the previous test, we will also perform a short test (about 30 mins long) to find the center of the field.

Prerequisites

• Knowledge of Argos light source magnitude and the possibility of tuning its brightness.

Procedure for the Tip-Tilt internal fast loop test

• Use ARGOS light source (to be used only at zenith) and direct light towards SHARK-NIR.
• Close the SOUL AO loop to have the best ASM shape. Keep the ASM static with the best shape.
• Close the SHARK-NIR internal tip-tilt loop.
• Take 10mins of data at the CRED2 (at loop frame rate) and SCICAM.
• Introduce 0.5" seeing at the ASM and close the loop.
• Close the SHARK-NIR internal tip-tilt loop.
• Take 10mins of data at the CRED2 and SCICAM.
• Introduce 0.8" seeing at the ASM and close the loop.
• Close the SHARK-NIR internal tip-tilt loop.
• Take 10mins of data at the CRED2 and SCICAM.
• Repeat the above steps for the selected brightness of the Argos light source

Procedure for finding the field center

• Use ARGOS light source (to be used only at zenith) and direct light towards SHARK-NIR.
• Close the SOUL AO loop to have the best ASM shape. Keep the ASM static with the best shape.
• Keep the SHARK-NIR internal tip-tilt loop OPEN.
• Move the derotator in 10 degrees (TBD) step and take an image at each position. From the data taken, estimate the center of the field.

Templates

Success criteria

• SHARK-NIR fast tip-tilt loop works efficiently within the requirements in all the seeing conditions.
• The center of field estimated.

Notes

• For the SN team: know in advance how many minutes of data can be downloaded from CRED2 or the ring-buffer size.

LBTO support

• Authorize SHARK-NIR
• Permission to use SX-ASM and LBTI-AO
• SOUL-LBTI AO support
• AO support

Date performed and by whom November 10th Luca, Daniele, Elena and remote support by Fulvio