Target selection and imaging requirements for JWST fine phasing

Joseph Jacob Green; Bruce H. Dean; Catherine M. Ohara; David C. Redding; Yan Zhang

doi:10.1117/12.552433

12 October 2004 Target selection and imaging requirements for JWST fine phasing

Joseph Jacob Green, Bruce H. Dean, Catherine M. Ohara, David C. Redding, Yan Zhang

Proceedings Volume 5487, Optical, Infrared, and Millimeter Space Telescopes; (2004) https://doi.org/10.1117/12.552433
Event: SPIE Astronomical Telescopes + Instrumentation, 2004, Glasgow, United Kingdom

Abstract

To achieve and maintain the fine alignment of its segmented primary mirror the James Webb Space Telescope (JWST) plans to use focus-diverse wavefront sensing (WFS) techniques with science camera imagery. The optical requirements for JWST are such that the error contribution from the WFS itself must be limited tp 10nm rms over the controllable degrees of freedom of the telescope. In this paper, we will explore the requirements on the target selection and imaging requirements necessary to achieve the desired level of WFS accuracy. Using Monte Carlo simulations we explore the WFS error as a function of wavefront aberrations level, defocus-diversity level, optical bandwidth and imaging signal-to-noise ratio to establish the key imaging requirements. By taking into account practical integration time limits along with the distribution of the defocused point-spread functions, we establish the bright and faint star magnitude limits suitable for WFS target selection.

Citation Download Citation

Joseph Jacob Green, Bruce H. Dean, Catherine M. Ohara, David C. Redding, and Yan Zhang "Target selection and imaging requirements for JWST fine phasing", Proc. SPIE 5487, Optical, Infrared, and Millimeter Space Telescopes, (12 October 2004); https://doi.org/10.1117/12.552433

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available