The project is simultaneoulsy developing the EST adaptive optics system and a multi-conjugated adaptive optics testbed
Top: Illumination system (Figure1) and turbulence simulator (Figure 2). Bottom: Wavefront sensor (Figure 3).
EST specialises in high spatial and temporal resolution, and shall correct the image blur due to turbulence in the Earth's atmosphere. To do so, it will include an innovative adaptive optics (AO) system.
The project is simultaneously developing a final AO system and a laboratory multi-conjugated adaptive optics (MCAO) testbed. The testbed will have reduced capabilities than the telescope AO, but it shall be commissioned in advance, so the lessons learned will improve the final design of the telescope MCAO system. The main components of the MCAO testbed are:
- Illumination system. It provides different sources required in the testbed, both for calibration and for performing the MCAO tests. It is composed by a LED source illuminating the integrated sphere and an object mask.
- Turbulence simulator. This system provides turbulence at the entrance of the testbed, simulating the turbulence expected in EST but adapted to the constrains imposed by the optomechanical design of the testbed. The simulator can emulate a vertical profile with 5 tuneable altitudes.
- Wavefront Sensor. Two different wavefront sensing strategies will be implemented: correlation Shark-Hartmann wavefront sensing and Artificial Neural Networks. The wavefront sensor optics and camera design shall be similar for both strategies, only the microlens array and the image processing will change.
- Deformable mirrors. Three ALPAO deformable mirrors are under construction, one with 820 actuators and two with 468 actuators.
Each module has been characterised independently and the whole testbed will be operative during the next months. In parallel, simulations and new reconstruction strategies have been developed to be implemented on the bench.