High precision heliostat for long path light tracking
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Discipline
Physical sciences
Subject
Cameras
Charge coupled devices
Data acquisition
Heliostats (instruments)
Mirrors
Optical systems
Remote sensing
Solar absorbers
Spectroscopic analysis
Brucker 120M spectrometer
Solar beams
Automatic target recognition
Audience
Scientific
Date
2003Metadata
Show full item recordDescription
A heliostat has been designed and built for use in optical remote sensing of the atmosphere. The heliostat uses two flat mirrors to track the sun and direct the sunlight to optical instruments. A stepper motor driven horizontal turntable is used to track the sun in azimuth and support an elevation assembly and a mechanical tower. The stepper motor driven elevation assembly drives an acquisition mirror that tracks the sun in elevation. This mirror directs the solar beam to a secondary mirror fixed on the mechanical tower. The secondary mirror then directs the solar beam along the axis of the tracker for use in measurements. A sensitive, high resolution CCD camera, receives a small part of the solar beam to analyze for fine servo-control. Ground based tests have demonstrated this instrument's tracking capability for the sun, the moon, stars and for long pathlength sources. Presently, this system is coupled with a high-resolution Brucker 120M spectrometer used to obtain solar absorption spectra. The heliostat directs the solar radiation along the spectrometer optical axis. The pointing precision was measured to be better than 0.5 arcsec. A description of the heliostat is presented, as well as the results of ground tests.
Citation
Hawat, T.; Stephen, T.M.; De Maziere, M.; Neefs, E. (2003). High precision heliostat for long path light tracking. , Proceedings of SPIE 5082, Acquisition, Tracking, and Pointing XVII, Vol. 5082, 13-20, DOI: 10.1117/12.499060.Identifiers
scopus: 2-s2.0-0242719979
Type
Conference
Peer-Review
No
Language
eng