Limitations and problems

  • The retrieval is performed only for pixels where the satellite zenith angle is less than 70 degrees.
  • SPhR products are available for clear (cloud-free) pixels only.
  • Since it is an iterative physical retrieval, computation is relatively expensive and reduction of resolution might be necessary to process large regions.
  • The products may contain significant errors over mountainous regions with large differences between the real topography and the topography used in the NWP model and/or in the SPhR retrieval algorithm, as well as in desert pixels, where surface emissivity is not well known, and in pixels contaminated with undetected cloud (see Chapter IV).