Linear controller error budget assessment for classical adaptive optics systems.

Area of Science:

• Astronomy and Astrophysics
• Optical Engineering
• Control Systems

Background:

• Adaptive optics (AO) systems are essential for high-resolution astronomical imaging.
• Understanding AO system limitations is critical for designing next-generation telescopes like the Very Large Telescope (VLT) and Extremely Large Telescope (ELT).
• Controller performance significantly impacts AO system accuracy and overall effectiveness.

Purpose of the Study:

• To develop a comprehensive error budget assessment formalism for linear controllers in AO systems.
• To analyze the potential of various controllers for VLT and ELT adaptive optics.
• To specifically address control-dependent errors within AO system design.

Main Methods:

• Developed an analytic formalism based on disturbance temporal power spectral density (PSD) and controller transfer functions.
• Applied the formalism to a NAOS/VLT-type single conjugated AO system.
• Utilized simulated turbulence and wavefront sensor measurements to derive disturbance PSDs.

Main Results:

• Detailed error budgets were constructed for integrator and Linear Quadratic Gaussian (LQG) controllers.
• The formalism allows for the assessment of control-dependent errors, highlighting their significance.
• The method is applicable to various AO configurations, including single- and multi-conjugated systems.

Conclusions:

• The proposed error budget formalism provides a robust tool for AO system design and controller selection.
• The findings are directly applicable to current AO systems and scalable to future ELT-sized systems.
• Further research can extend this formalism to more complex AO configurations and control strategies.