Solar-light shielding using a near-hemispherical lens for a star sensor

Hiroyuki Kawano; Haruhiko Shimoji; Shoji Yoshikawa; Katsumasa Miyatake; Kazumori Hama; Shuji Nakamura

doi:10.1117/1.2402101

1 December 2006 Solar-light shielding using a near-hemispherical lens for a star sensor

Hiroyuki Kawano, Haruhiko Shimoji, Shoji Yoshikawa, Katsumasa Miyatake, Kazumori Hama, Shuji Nakamura

Author Affiliations +

Optical Engineering, Vol. 45, Issue 12, 124403 (December 2006). https://doi.org/10.1117/1.2402101

Abstract

We have developed a light-shielding technique for a star sensor that can shorten the baffle length. We achieved a baffle length of 120 mm, two-thirds that of a conventional two-stage baffle. The key idea is that the first lens of the imaging optics is designed as a near-hemispherical (NHS) lens that can work as an angle filter; high-incidence-angle rays are not permitted to be transmitted but low-incidence-angle rays from stars can be. A star sensor system with the new light-shielding technique onboard the SERVIS-1 satellite was launched in October 2003 as an experimental device. Though the in-orbit data verified its fundamental performance in capturing star images, undesirable solar background noise was observed in two corners of the field of view. Ray-trace simulations revealed that slight scattered light on the specular baffle surface entered the NHS lens and reached the corners of the image sensor through a multireflection path inside the lens. We redesigned the baffle and confirmed that stray light was reduced below maximum acceptable levels in a ground test. The star sensor with redesigned baffles is planned to be installed as the main attitude sensor for the SERVIS-2 satellite to be launched in 2008 or later.

©(2006) Society of Photo-Optical Instrumentation Engineers (SPIE)

Citation Download Citation

Hiroyuki Kawano, Haruhiko Shimoji, Shoji Yoshikawa, Katsumasa Miyatake, Kazumori Hama, and Shuji Nakamura "Solar-light shielding using a near-hemispherical lens for a star sensor," Optical Engineering 45(12), 124403 (1 December 2006). https://doi.org/10.1117/1.2402101

Published: 1 December 2006

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