The Ozone Monitoring Instrument-Imaging Spectrometer (OMI and ImS) is a trace gas monitoring instrument in the line of GOME. OMI provides nadir viewing UV-visible spectroscopy with a resolution sufficient to separate out the various absorbing trace gases present in a wavelength range of 270 to 780 nm. This includes O3, SO2, BrO, OCIO, HCHO, NO2, NO3 and water vapor. O2 is also measured and is used to derive cloud top heights and cloud cover. The ImS is different as compared to the GOME in the sense that a 2D CCD is used as detector instead of a 1D diode array. The first dimension of the CCD is used to detect spectral information and the second dimension is used to image the swath perpendicularly to the track of the satellite. The concept allows to have a wide swath together with good horizontal resolution, has a polarization scrambler and room temperature detectors. A special add-on channel measures, at reduced resolution, polarization in three directions for the full spectral range. This channel is meant to enhance aerosol and PSC data products. The ImS is intended for flight on the ESA/Eumetsat METOP satellites.