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https://gnanaganga.inflibnet.ac.in:8443/jspui/handle/123456789/7452
Title: | Autofocus System for Space Cameras |
Authors: | Zhaohui Li Keyong Wu |
Issue Date: | 2005 |
Publisher: | Optical Engineering |
Abstract: | A novel autofocusing technique using a self-imaging approach is developed for a space camera having large aperture and long focus. Its optical system consists of an emitting system, receiving system, and two pentagonal prisms. The emitting system has three parts: a light source, beamsplitter, and aim slit. The receiving system includes a field lens, two separate lenses, and CCD. Using two little pentaprisms instead of a large planar mirror makes the autofocus system simple and compact. A defocused signal is acquired by measuring the change of the slit self-image position imaged on the CCD. The algorithm to calculate the movement of the slit self-image position is analyzed to achieve subpixel position estimation. The results of the experiments show a ::t 10-µ.m precision of autofocusing in a range of ::t 5-mm defocusing. The system demonstrates high resolution, easy adjustment, and high reliability. Also this method can meet the requirements of various accurate focus measurement systems |
URI: | http://gnanaganga.inflibnet.ac.in:8080/jspui/handle/123456789/7452 |
Appears in Collections: | Articles to be qced |
Files in This Item:
File | Size | Format | |
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Autofocus system for space cameras.pdf Restricted Access | 2.34 MB | Adobe PDF | View/Open Request a copy |
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