5 December 2001 Design, tolerancing, and alignment of pushbroom imaging spectrometers for high-response uniformity
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We present a design and tolerancing approach that permits the achievement of a high degree of spatial and spectral uniformity of response from a pushbroom imaging spectrometer. Such uniformity of response is crucial for the extraction of accurate spectroscopic information from remotely sensed data. The spectrometer system example comprises two independent spectrometer modules covering the 400 - 2500 nm range, separated through a dichroic mirror. The relative merits of alternative approaches are briefly reviewed before concentrating on the problem of building a flight-worthy system that can approximate its design performance. The tolerancing approach requires simultaneous monitoring of many parameters, and specifically: overall image quality, spectral distortion, spectral MTF variation with field, spatial distortion, spatial MTF variation with wavelength, and slit magnification to within a small fraction of a pixel. It is shown that the wavefront error alone or even supplemented by distortion figures is insufficient for characterizing a system with high response uniformity. Tolerance values on the components and their positioning are primarily guided by the need to achieve the same magnification between the two spectrometer modules, as well as by the interferometric alignment method.
© (2001) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Pantazis Z. Mouroulis, James J. Shea, David A. Thomas, "Design, tolerancing, and alignment of pushbroom imaging spectrometers for high-response uniformity", Proc. SPIE 4441, Current Developments in Lens Design and Optical Engineering II, (5 December 2001); doi: 10.1117/12.449557; https://doi.org/10.1117/12.449557

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