Desensitization optimization method for a space camera with a tiltable secondary mirror based on the nodal aberration...

Area of Science:

• Optical Engineering
• Space Optics
• Image Stabilization

Background:

• Space cameras experience vibrations during in-orbit imaging, causing image blur and positioning errors.
• Catadioptric systems use secondary mirror (SM) tilt for image stabilization, but it induces aberrations, degrading imaging quality.

Purpose of the Study:

• To develop a desensitization optimization method for space cameras with tiltable secondary mirrors.
• To analytically derive expressions for astigmatism and coma sensitivity to SM tilt using nodal aberration theory (NAT).

Main Methods:

• Systematic derivation of analytical expressions for astigmatism and coma sensitivity to SM tilt based on NAT.
• Construction of a desensitization evaluation function using the root mean square of sensitivity.
• Proposal and validation of a desensitization optimization method through optical design case studies.

Main Results:

• The proposed method significantly enhances modulation transfer function (MTF) values at the Nyquist frequency under ±0.05° SM tilt.
• Improved image quality across the entire field of view and strengthened system tolerance performance.
• Outperformed conventional methods and SAB optimization in imaging performance.

Conclusions:

• The novel method effectively enhances imaging stability for space cameras in disturbed environments.
• Maintains structural rationality while improving overall imaging performance.
• Provides a robust solution for high-precision image stabilization in space optics.