The Ozone Mapping and Profiler Suite (OMPS) is being developed for the United States National Polar-orbiting Operational Environmental Satellite System (NPOESS). We describe the optical design and predict the performance of the OMPS earth limb-imaging spectrometer. Limb-scattered solar radiation is measured at selected ultraviolet (UV), visible, and near infrared (NIR) wavelengths to determine ozone profile concentrations for the altitude range of 8 to 60 km. The sensor consists of a telescope with three separate crosstrack fields of view of the limb, a prism spectrometer covering 290 to 1050 nm, and a solar-diffuser calibration mechanism. The sensor provides 3 km vertical resolution profiles of atmospheric radiance with channel spectral resolutions (full-width at half-maximum, FWHM) ranging from 2.7 nm in the UV to 35 nm in the NIR and handles the demanding spectral and spatial dynamic range of the limb-scattered solar radiation with the required sensitivity for ozone retrievals.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.