NOTE: Fresco is not currently available.

FRESCO (Full RESolution Survey COadd) produces full resolution coadded images from the IRAS raw survey data. They are referred to as "full resolution" because they use the raw data (Calibrated Raw Detector Data, or CRDD) without applying any resolution enhancement techniques or smoothing. Hence the resolution of the data are approximately the size of the detectors in the various wavelength bands:

  • ~ 1'x5' at 12 and 25 µm
  • ~ 2'x5' at 60 µm
  • and ~ 4'x5' at 100 µm

The pixel size used is small compared to the detector size for all bands, so the resolution loss from binning is negligible.

FRESCOs are 1 degree by 1 degree or 2 degrees by 2 degrees in size, and the user can choose either 15" or 30" pixels for the coadded image. The user also has control over what survey data goes into the coadd.

Users who are familiar with the IRAS two-dimensional data products produced prior to 1989 should note that FRESCO differs from the old IBM DSCO processing in two ways.

  • First, it uses the IRAS detector response functions for binning and coadding detector fluxes. These functions more accurately model the detector than the rectangular box apertures used in the DSCO coadder, thus improving photometry.
  • Second, the user can now choose between two methods of de-striping the coadded data. In addition to the de-striping method implemented in DSCO (cross-scan offset removal), the detector baselines can be removed by iteratively fitting each detector scan to a linear baseline and subtracting it.

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(Interpreting SCANPI Results) (FRESCO Processing)