Segment-level thermal sensitivity analysis for exo-Earth imaging

TL;DR

This paper develops a detailed segment-level thermal sensitivity analysis for space telescopes, linking temperature gradients to wavefront errors and estimating their impact on exoplanet imaging contrast.

Contribution

It introduces a novel segment-level wavefront stability error budget using finite element modeling and the PASTIS sensitivity approach for exo-Earth imaging.

Findings

Quantifies wavefront variations due to temperature gradients at the segment level.

Provides static and dynamic tolerance allocations for telescope segments.

Estimates the impact on imaging contrast and stability for exoplanet detection.

Abstract

We present a segment-level wavefront stability error budget for space telescopes essential for exoplanet detection. We use a detailed finite element model to relate the temperature gradient at the location of the primary mirror to wavefront variations on each of the segment. We apply the PASTIS sensitivity model forward approach to allocate static tolerances in physical units for each segment, and transfer these tolerances to the temporal domain via a model of the WFS&C architecture in combination with a Zernike phase sensor and science camera. We finally estimate the close-loop variance and limiting contrast for the segments' thermo-mechanical modes.