The EarthCARE satellite mission objective is the observation of clouds and aerosols from low Earth orbit. The key spatial context providing instrument within the payload suite of 4 instruments is the Multi-Spectral Imager (MSI), previously described in . The MSI is intended to provide information on the horizontal variability of the atmospheric conditions and to identify e.g. cloud type, textures, and temperature. It will form Earth images at 500m ground sample distance (GSD) over a swath width of 150km; it will image Earth in 7 spectral bands: one visible, one near-IR, two short-wave IR and three thermal IR. The instrument will be comprised of two key parts:<p> </p>• a visible-NIR-SWIR (VNS) optical unit radiometrically calibrated using a sun illuminated quasivolume diffuser and shutter system<p> </p>• a thermal IR (TIR) optical unit radiometrically calibrated using cold space and an internal black-body. This paper, being the first of a sequence of two, will provide an overview of the MSI and enter into more detail the critical performance parameters and detailed design the MSI TIR optical design.<p> </p>The TIR concept is to provide pushbroom imaging of its 3 bands through spectral separation from a common aperture. The result is an efficient, well controlled optical design without the need for multiple focal plane arrays. The designed focal plane houses an area array detector and will meet a challenging set of requirements, including radiometric resolution, accuracy, distortion and MTF.
The Tropospheric Monitoring Instrument, TROPOMI, is a passive UV-VIS-NIR-SWIR spectrograph, which uses sun
backscattered radiation to study the Earth's atmosphere and to monitor air quality, on both global and local scale. It
follows in the line of SCIAMACHY (2002) and OMI (2004), both of which have been very successful. OMI is still
operational. TROPOMI is scheduled for launch in 2015. Compared with its predecessors, TROPOMI will take a major
step forward in spatial resolution and sensitivity. The nominal observations are at 7 x 7 km<sup>2</sup> at nadir and the signal-tonoises
are sufficient for trace gas retrieval even at very low albedos (2 to 5%). This allows observations of air quality at
sub-city level. TROPOMI has reached CDR status and production of flight model units has started. Flight detectors have
been produced and detector electronics is expected to be finished by mid-2013. The instrument control unit is undergoing
extensive tests, to ensure full instrument functionality. Early results are promising and this paper discusses these H/W
results, as well as some challenges encountered during the development of the instrument.
The EarthCARE satellite mission objective is the observation of clouds and aerosols from low Earth orbit. The key
spatial context providing instrument within the payload suite of 4 instruments is the Multi-Spectral Imager (MSI).The
MSI will take data at 500m ground sample distance (GSD) over a swath width of 150 km via pushbroom imaging. One
part of the MSI instrument will be a thermal IR optical unit (TIROU). We describe the design of the focal plane array for
the TIROU, its time-delay and integration readout scheme and present results derived from its associated simulator.