Title :
An optical line of sight sensor for the pinhole facility
Author :
Greene, Michael ; Tan, Hong
Author_Institution :
Dept. of Electr. Eng., Auburn Univ., AL, USA
Abstract :
A scale model of the optical line-of-sight sensor that measures the pointing angle error to the sun for the Space-Shuttle-based pinhole facility has been designed and tested in the laboratory. This sensor consists of a pinhole camera with two pairs of perpendicularly mounted linear photodiode arrays to detect the intensity distribution of the solar image produced by the pinhole. The video signal of the arrays is digitized and transferred into a microcomputer. The deflection of the image center, which expresses the pointing error, is calculated from these data. The experimental results show that the sensor can estimate the pointing error of 0.0167 arc-s resolution and 0.0032 arc-s r.m.s. accuracy for the full-scale system when the pinhole is 32 m from the detector
Keywords :
X-ray apparatus; X-ray astronomy; astronomical telescopes; attitude control; cameras; computerised picture processing; laboratory apparatus and techniques; microcomputer applications; photodetectors; photodiodes; position measurement; space vehicles; Space-Shuttle-based pinhole facility; Sun; X-ray telescope; digitization; image center deflection; image displacement; intensity distribution; laboratory scale model; microcomputer; optical line-of-sight sensor; perpendicularly mounted linear photodiode arrays; pinhole camera; pinhole facility; pointing angle error; r.m.s. accuracy 0.0032 arc s; resolution 0.0167 arc s; solar image; solar instrumentation; sun; video signal; Cameras; Goniometers; Image sensors; Laboratories; Optical design; Optical sensors; Photodiodes; Sensor arrays; Sun; Testing;
Conference_Titel :
System Theory, 1989. Proceedings., Twenty-First Southeastern Symposium on
Conference_Location :
Tallahassee, FL
Print_ISBN :
0-8186-1933-3
DOI :
10.1109/SSST.1989.72526
