LAUNDR is the program that performs preliminary data clean-up for two of IPAC's IRAS data processors, the FRESCO Full RESolution Survey COadder and the HIRES resolution enhancement processor.

LAUNDR performs two primary functions. One, "de-glitching", is the flagging for removal (in YORIC) of spurious non-source-like signals called glitches, typically caused by radiation hits on individual detectors. The second, "de-striping", is the minimization of detector-to-detector response variations.

There are two de-striping methods available in LAUNDR:

  • The default method, known as "baseline removal", fits a linear baseline to each individual detector scan and subtracts it, bringing all the scans to a flat background. Baseline removal is sometimes also called "flattening" because it removes any planar gradient in the background.
  • The second de-striping option is called "cross-scan offset removal". Cross-scan offset de-striping maintains the approximate DC level of the background and does not substantially affect overall gradients. It simply removes a DC offset from each scan, attempting to bring all scans to a common background level.

Baseline removal usually does a better job of removing the stripes from the data, but cross-scan offset de-striping may perform better when the field has so much structure that a good linear fit cannot be achieved. In some extreme cases, for example, extremely confused regions, neither de-striper will work very well. In these cases better results may be obtained by processing the data with no de-striping.

LAUNDR is more fully described in the LAUNDR Software Design Specification (J.W. Fowler and M.Melnyk, 1989, IPAC, Pasadena).