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Multispectral Microimager for AstrobiologyA primary goal of the astrobiology program is the search for fossil records. The astrobiology exploration strategy calls for the location and return of samples indicative of environments conducive to life, and that best capture and preserve biomarkers. Successfully returning samples from environments conducive to life requires two primary capabilities: (1) in situ mapping of the mineralogy in order to determine whether the desired minerals are present; and (2) nondestructive screening of samples for additional in-situ testing and/or selection for return to laboratories for more in-depth examination. Two of the most powerful identification techniques are micro-imaging and visible/infrared spectroscopy. The design and test results are presented from a compact rugged instrument that combines micro-imaging and spectroscopic capability to provide in-situ analysis, mapping, and sample screening capabilities. Accurate reflectance spectra should be a measure of reflectance as a function of wavelength only. Other compact multispectral microimagers use separate LEDs (light-emitting diodes) for each wavelength and therefore vary the angles of illumination when changing wavelengths. When observing a specularly-reflecting sample, this produces grossly inaccurate spectra due to the variation in the angle of illumination. An advanced design and test results are presented for a multispectral microimager which demonstrates two key advances relative to previous LED-based microimagers: (i) acquisition of actual reflectance spectra in which the flux is a function of wavelength only, rather than a function of both wavelength and illumination geometry; and (ii) increase in the number of spectral bands to eight bands covering a spectral range of 468 to 975 nm.
Document ID
20080013262
Document Type
Preprint (Draft being sent to journal)
External Source(s)
Authors
Sellar, R. Glenn (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Farmer, Jack D. (Arizona State Univ. AZ, United States)
Kieta, Andrew (Mount San Antonio Coll. Walnut, CA, United States)
Huang, Julie (California Inst. of Tech. Pasadena, CA, United States)
Date Acquired
August 24, 2013
Publication Date
August 13, 2006
Subject Category
Instrumentation and Photography
Meeting Information
SPIE Optics and Photonics Symposium , Instruments, Methods, and Missions for Astrobiology X(San Diego, CA)
Distribution Limits
Public
Copyright
Other
Keywords
microimager
multispectral imager
astrobiology