# Reduced Order Estimation of the Speckle Electric Field History for Space-Based Coronagraphs

## TL;DR

This paper introduces a reduced-order electric field estimation method for space-based coronagraphs that accounts for deformable mirror actuation, improving the modeling of speckle evolution in exoplanet imaging.

## Contribution

It presents a novel reduced-order electric field estimation approach incorporating deformable mirror dithering, requiring fewer modes than traditional intensity-based PCA methods.

## Key findings

- Lower number of modes needed for accurate electric field estimation
- Effective simulation results with FALCO for WFIRST coronagraph
- Potential for improved exoplanet imaging contrast

## Abstract

In high-contrast space-based coronagraphs, one of the main limiting factors for imaging the dimmest exoplanets is the time varying nature of the residual starlight (speckles). Modern methods try to differentiate between the intensities of starlight and other sources, but none incorporate models of space-based systems which can take into account actuations of the deformable mirrors. Instead, we propose formulating the estimation problem in terms of the electric field while allowing for dithering of the deformable mirrors. Our reduced-order approach is similar to intensity-based PCA (e.g. KLIP) although, under certain assumptions, it requires a considerably lower number of modes of the electric field. We illustrate this by a FALCO simulation of the WFIRST hybrid Lyot coronagraph.