A window is applied to the spectral image data along the λ dimension, to select a subset of the spectral image data corresponding to {HEAD ~ a range} of {TAIL ~ wavelengths} 
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A window is applied to the spectral image data along the λ dimension , to select a subset of the spectral image data corresponding to { HEAD ~ a range } of { TAIL ~ wavelengths }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL