High fidelity point-spread function retrieval in the presence of electrostatic, hysteretic pixel response

TL;DR

This paper develops a method to accurately retrieve the point-spread function in CCD sensors by modeling electrostatic pixel responses, aiming to reduce sensor-induced errors in high-precision astronomical imaging.

Contribution

It introduces a novel approach combining electrostatic drift calculations with flat field data to constrain pixel distortions and improve FPSF estimation in CCD sensors.

Findings

Validated model against operational data across voltage settings

Demonstrated improved FPSF accuracy in high-contrast conditions

Proposed laboratory tests to measure hysteretic pixel responses

Abstract

We employ electrostatic conversion drift calculations to match CCD pixel signal covariances observed in flat field exposures acquired using candidate sensor devices for the LSST Camera. We thus constrain pixel geometry distortions present at the end of integration, based on signal images recorded. We use available data from several operational voltage parameter settings to validate our understanding. Our primary goal is to optimize flux point-spread function (FPSF) estimation quantitatively, and thereby minimize sensor-induced errors which may limit performance in precision astronomy applications. We consider alternative compensation scenarios that will take maximum advantage of our understanding of this underlying mechanism in data processing pipelines currently under development. To quantitatively capture the pixel response in high-contrast/high dynamic range operational extrema, we propose herein some straightforward laboratory tests that involve altering the time order of source illumination on sensors, within individual test exposures. Hence the word {\it hysteretic} in the title of this paper.