Metasurface-enabled small-satellite polarisation imaging

Fuente: arXiv
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Main Authors: Dean, Sarah E., Munro, Josephine, Li, Neuton, Sharp, Robert, Neshev, Dragomir N., Sukhorukov, Andrey A.
Format: Preprint
Published: 2024
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author Dean, Sarah E.
Munro, Josephine
Li, Neuton
Sharp, Robert
Neshev, Dragomir N.
Sukhorukov, Andrey A.
author_facet Dean, Sarah E.
Munro, Josephine
Li, Neuton
Sharp, Robert
Neshev, Dragomir N.
Sukhorukov, Andrey A.
contents Polarisation imaging is used to distinguish objects and surface characteristics that are otherwise not visible with black-and-white or colour imaging. Full-Stokes polarisation imaging allows complex image processing like water glint filtering, which is particularly useful for remote Earth observations. The relatively low cost of small-satellites makes their use in remote sensing more accessible. However, their size and weight limitations cannot accommodate the bulky conventional optics needed for full-Stokes polarisation imaging. We present the modelling of an ultra-thin topology-optimised diffractive metasurface that encodes polarisation states in five different diffraction orders. Positioning the metasurface in a telescope's pupil plane allows the diffraction orders to be imaged onto a single detector, resulting in the capability to perform single-shot full-Stokes polarisation imaging of the Earth's surface. The five rectangular image swaths are designed to use the full width of the camera, and then each successive frame can be stitched together as the satellite moves over the Earth's surface, restoring the full field of view achievable with any chosen camera without comprising the on-ground resolution. Each set of four out of the five orders enables the reconstruction of the full polarisation state, and their simultaneous reconstructions allow for error monitoring. The lightweight design and compact footprint of the polarisation imaging optical system achievable with a metasurface is a novel approach to increase the functionality of small satellites while working within their weight and volume constraints.
format Preprint
id arxiv_https___arxiv_org_abs_2412_06132
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Metasurface-enabled small-satellite polarisation imaging
Dean, Sarah E.
Munro, Josephine
Li, Neuton
Sharp, Robert
Neshev, Dragomir N.
Sukhorukov, Andrey A.
Optics
Instrumentation and Methods for Astrophysics
Polarisation imaging is used to distinguish objects and surface characteristics that are otherwise not visible with black-and-white or colour imaging. Full-Stokes polarisation imaging allows complex image processing like water glint filtering, which is particularly useful for remote Earth observations. The relatively low cost of small-satellites makes their use in remote sensing more accessible. However, their size and weight limitations cannot accommodate the bulky conventional optics needed for full-Stokes polarisation imaging. We present the modelling of an ultra-thin topology-optimised diffractive metasurface that encodes polarisation states in five different diffraction orders. Positioning the metasurface in a telescope's pupil plane allows the diffraction orders to be imaged onto a single detector, resulting in the capability to perform single-shot full-Stokes polarisation imaging of the Earth's surface. The five rectangular image swaths are designed to use the full width of the camera, and then each successive frame can be stitched together as the satellite moves over the Earth's surface, restoring the full field of view achievable with any chosen camera without comprising the on-ground resolution. Each set of four out of the five orders enables the reconstruction of the full polarisation state, and their simultaneous reconstructions allow for error monitoring. The lightweight design and compact footprint of the polarisation imaging optical system achievable with a metasurface is a novel approach to increase the functionality of small satellites while working within their weight and volume constraints.
title Metasurface-enabled small-satellite polarisation imaging
topic Optics
Instrumentation and Methods for Astrophysics
url https://arxiv.org/abs/2412.06132