An optical spectrometer distinguishes ambiguity between different wavelength constituent components present in incident light. A spatial filter in the spectrometer spatially filters the incident light. A dispersion system receives the spatially filtered light and disperses images of the spatial filter in a wavelength dependent fashion such that two or more wavelength-specific images at least partially overlap at a detector system. The detector system comprises a detector array and processor that detects and processes the dispersed light to remove ambiguity between one or more of the overlapping images. The detector array may detect coded aperture images associated with a coded aperture spatial filter defined by a coded aperture function, and the processor may process the detector array output signals using an analysis function that complements the coded aperture function. The detector system may filter the spatial filter images and electronically process the resulting detector array output signals.