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Q: Is it possible to obtain the auxiliary data used in the processing, e.g. absorption cross sections, through the USF? A: Nominally, all data identified as auxiliary data in the Envisat product specification can be ordered via ESA's EO helpdesk, provided the user has been given the relevant privilege, i.e. the data is on the list of products he can order. The absorption cross-sections, for instance, are contained in the product named "SCI_BL2_AX*". Many of the currently used auxiliary files can be downloaded from the ESA web site. (updated: 3 May 2005) Q: How do I extract geolocation information belonging to a measurement from a SCIAMACHY PDS file A: The geolocation information (e.g., the pixel coordinates) is stored in a data block separate from the measurement data (e.g., a total ozone column measurement). The appropriate geolocation information, i.e. belonging to a specific measurement, thus has to be extracted from this data block. The procedure is not trivial, and is explained in more detail in this document. For further information please contact Jan Fokke Meirink. (updated: 20 January 2003) Q: How can I distinguish between forward and backward scans? A: The SCIAMACHY PDS files do not give information on the pixel type (forward or backward scan). If, for some reason, you want to make this distinction, you may use the following function. For further questions please contact Jan Fokke Meirink. (updated: 20 January 2003) Q: What is the ground pixel size for the different SCIAMACHY products A: The ground pixel size for the nadir measurements (total columns) depends on the wavelength region used for the retrieval and on the orbital position. Here is a picture, made by Heinrich Bovensmann and Stefan Noel indicating the horizontal resolution (across track) for different wavelength regions along the orbit (valid around Equinox). UV/DOAS is the wavelength region for O3, Vis/DOAS for NO2. The across-track ground pixel size for limb measurements, i.e. for profiles, also varies along the orbit (between 240 km and 960 km). (updated: 29 August 2002) Q: When will Sciamachy start measurements? A: Sciamachy has started nominal measurements on 18 July 2002. Nominal measurements will be interrupted by non-nominal measurements (to check instrument functionality and calibration) for a total period of a few weeks until then end of 2002. The planned measurement schedule can be found via the website of the SCIAMACHY Operations Support Team. (updated: 29 August 2002) Q: When and how will the Sciamachy products be available for the validation teams? A: In principle the distribution of products to the validation teams should go as described in detail in this ESA document. The current status for the various products is as follows:
Last update: 09-10-2007
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