NASA Logo

NTRS

NTRS - NASA Technical Reports Server

The auto‑search feature has been disabled based on user feedback. Enter a search term/phrase and click “Search” to begin.

Back to Results
Impact of Near-Angle Scatter on Exo-Earth CoronagraphyNear-Angle Scatter (NAS) of the host star’s light may limit the ability of a potential Habitable Worlds Observatory (HWO) to detect and characterize an Earth-like planet around a Sun-like star via coronagraphy. NAS from each optical surface produces an E-field across the dark hole that is coherent. These E-fields sum and could be as large or larger than the coronagraph mask leakage E-field. NAS E-fields contribute to the dark hole noise floor via both shot noise and heterodyne amplification of the wavefront instability. The amount of NAS is determined entirely by the statistical properties of the optical surface microroughness and the operating wavelength. Surface properties include not only the rms roughness, but also correlation length and the functional form of the distribution itself. This paper derives an expression that specifies the surface statistics required to achieve a given coronagraph error budget NAS throughput allocation. Analysis does not include scatter from coating columnar structure, edges, contamination, micrometeoroid impacts, or polarization.
Document ID
20240007049
Acquisition Source
Marshall Space Flight Center
Document Type
Conference Paper
Authors
H Philip Stahl
(Marshall Space Flight Center Redstone Arsenal, United States)
David D Smith
(Marshall Space Flight Center Redstone Arsenal, United States)
Bijan Nemati
(University of Alabama in Huntsville Huntsville, United States)
Date Acquired
May 31, 2024
Subject Category
Astrophysics
Meeting Information
Meeting: SPIE Astronomy 2024
Location: Yokohama
Country: JP
Start Date: June 16, 2024
End Date: June 21, 2024
Sponsors: International Society for Optics and Photonics
Funding Number(s)
WBS: 141108.04.16.01.07
Distribution Limits
Public
Copyright
Public Use Permitted.
Technical Review
Single Expert
No Preview Available