Impact of the visible detector design on GOES imager and sounder MTF

Frederick L. Williams; David R. Wickholm; John C. Ehlert

doi:10.1117/12.254101

18 October 1996 Impact of the visible detector design on GOES imager and sounder MTF

Frederick L. Williams, David R. Wickholm, John C. Ehlert

Proceedings Volume 2812, GOES-8 and Beyond; (1996) https://doi.org/10.1117/12.254101
Event: SPIE's 1996 International Symposium on Optical Science, Engineering, and Instrumentation, 1996, Denver, CO, United States

Abstract

The modulation transfer function is one of the GOES Imager and Sounder system's key optical performance indicators. Though the visible images from GOES-8 and GOES-9 are excellent, the MTF values measured during ground tests are below expectations. The 4490 cycle per radian frequency MTF is particularly interesting because it is not significantly affected by small changes in focus or aberrations of the optical system. The primary contributors to the ow MTF values which are within the instrument are the ghost reflections from the transmissive components and the detector and its package. The ghost reflections that exist are certainly a factor in the stray light. An estimate of each ghost's intensity produces a worst case effect on MTF of approximately 2.5 percent. The detector itself appears to be the largest contributor to the stray light. There are several ways that the detector and its package contribute to the stray light. The most prominent among them is the reflection from the aluminum coated substrate combined with the closeness of the detector window. The stray light form the detector reduces the MTF by approximately 4 percent. Instantaneous geometric field of view (IGFOV) curves verify the existence of the stray light and calculations show approximately the magnitude of difference between measured and expected MTF data. A new detector design appropriate for the Imager visible channel or the Sounder star sense channel incorporates the changes recommended to reduce stray light within the detector THe first of the new detectors qualifies for the Sounder star sense detector. IGFOV curves show the reduction in stray light levels by about a factor of 2 to 4. Sounder star sense optical MTF data shows approximately 8 percent increase in the MTF at 4490 cycles per radian compared to SN05 Sounder.

Citation Download Citation

Frederick L. Williams, David R. Wickholm, and John C. Ehlert "Impact of the visible detector design on GOES imager and sounder MTF", Proc. SPIE 2812, GOES-8 and Beyond, (18 October 1996); https://doi.org/10.1117/12.254101

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

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
12 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Sensors

Modulation transfer functions

Stray light

Imaging systems

Signal detection

Reflectivity

Reflection

Show All Keywords

Keywords/Phrases

Search In:

Publication Years