Share Email Print

Proceedings Paper

Preparation of the pointing and control system of the SOFIA Airborne Telescope for early science missions
Author(s): Ulrich Lampater; Terry Herter; Paul Keas; Franziska Harms; Christian Engfer; Peter Salewsky; Holger Jakob; Hans-Peter Roeser
Format Member Price Non-Member Price
PDF $17.00 $21.00

Paper Abstract

During observation flights the telescope structure of the Stratospheric Observatory for Infrared Astronomy (SOFIA) is subject to disturbance excitations over a wide frequency band. The sources can be separated into two groups: inertial excitation caused by vibration of the airborne platform, and aerodynamic excitation that acts on the telescope assembly (TA) through an open port cavity. These disturbance sources constitute a major difference of SOFIA to other ground based and space observatories and achieving the required pointing accuracy of 1 arcsecond cumulative rms or better below 70 Hz in this environment is driving the design of the TA pointing and control system. In the current design it consists of two parts, the rigid body attitude control system and a feed forward based compensator of flexible TA deformation. This paper discusses the characterization and control system tuning of the as-built system. It is a process that integrates the study of the structural dynamic behavior of the TA, the resulting image motion in the focal plane, and the design and implementation of active control systems. Ground tests, which are performed under controlled experimental conditions, and in-flight characterization tests, both leading up to the early science performance capabilities of the observatory, are addressed.

Paper Details

Date Published: 28 July 2010
PDF: 13 pages
Proc. SPIE 7733, Ground-based and Airborne Telescopes III, 77330S (28 July 2010); doi: 10.1117/12.856562
Show Author Affiliations
Ulrich Lampater, SOFIA Airborne Systems Operations Ctr., NASA Dryden Flight Research Ctr. (United States)
Terry Herter, Cornell Univ. (United States)
Paul Keas, CSA Engineering, Inc. (United States)
Franziska Harms, Kayser-Threde GmbH (Germany)
Christian Engfer, SOFIA Airborne Systems Operations Ctr., NASA Dryden Flight Research Ctr. (United States)
Peter Salewsky, Resolut GmbH (Germany)
Holger Jakob, SOFIA Airborne Systems Operations Ctr., NASA Dryden Flight Research Ctr. (United States)
Hans-Peter Roeser, Univ. Stuttgart (Germany)

Published in SPIE Proceedings Vol. 7733:
Ground-based and Airborne Telescopes III
Larry M. Stepp; Roberto Gilmozzi; Helen J. Hall, Editor(s)

© SPIE. Terms of Use
Back to Top
Sign in to read the full article
Create a free SPIE account to get access to
premium articles and original research
Forgot your username?