Modeling technique for the Hubble Space Telescope wave-front deformation.

Area of Science:

• Astrophysics
• Optical Engineering

Background:

• Hubble Space Telescope (HST) images were affected by spherical aberration caused by a primary mirror conic-constant error.
• The corrective optics space telescope axial replacement (COSTAR) program aimed to address these optical issues.

Purpose of the Study:

• To investigate the discrepancy between experimental and software-calculated point-spread functions (PSF) for the HST.
• To propose a novel modeling method for accurate PSF prediction.

Main Methods:

• Development of simulators to generate PSF for the telescope alone and with the faint-object camera.
• Comparison of experimental PSF data with results from standard optical software.
• Proposal of a modeling approach based on wave-front error determination at the exit-pupil level.

Main Results:

• Experimental PSF measurements were found to be identical to in-orbit data.
• Commonly used optical software failed to accurately replicate the observed PSF.
• The proposed wave-front error modeling method yielded results consistent with actual observations.

Conclusions:

• Standard optical software is insufficient for accurately modeling the HST's optical aberrations.
• A new modeling method focusing on exit-pupil wave-front error provides accurate PSF predictions.
• This advancement improves the understanding and correction of optical errors in space telescopes.