Field-of-view limitations of phased telescope arrays

Area of Science:

• Optical Engineering
• Astronomy
• Telescope Array Design

Background:

• Imaging phased telescope arrays are susceptible to performance degradation from various error sources.
• Residual optical aberrations in individual telescopes are fundamental error sources impacting array performance.

Purpose of the Study:

• To analyze how third-order field curvature and distortion affect optical performance in imaging phased telescope arrays.
• To predict field-dependent image degradation based on subaperture configurations and telescope design parameters.

Main Methods:

• Analysis of relative phase and tilt errors introduced by field curvature and distortion in array elements.
• Prediction of image degradation for varying subaperture sizes and telescope designs.
• Graphical presentation of quantitative results and tolerances for residual field curvature.

Main Results:

• Field curvature and distortion induce relative phase and tilt errors between telescopes in an array.
• For simple two-mirror telescopes, distortion limits the field of view to <5 arcmin (D < 0.5 m).
• Field curvature limits the field of view to <1 arcmin for subapertures >2 m.

Conclusions:

• Field curvature and distortion significantly degrade the optical performance of imaging phased telescope arrays.
• Achieving a 0.5-degree field of view for telescopes >2 m requires complex optical designs to meet stringent aberration tolerances.
• Aberration control is critical for scaling up phased array telescopes and achieving desired fields of view.