The ''M'' stands for MIPS. ''CHNLNUM'' is the header keyword for ''channel number,'' and channel 1 = 24 micron, channel 2 = 70 micron, and channel 3 = 160 micron. The AORKEY (also a header keyword) is a unique 10-digit number assigned to each AOR in our operations database. The EXPID (=exposure id, or number, also a header keyword) and DCENUM (=DCE number, also a header keyword) refers to where in the observing sequence this particular frame was obtained. The ''version'' refers to the number of times that this particular data set has been reprocessed through a validated pipeline. As the understanding of the instrument matured and the pipelines evolved, we reprocessed everything in the Archive, generally multiple times. Finally, ''type'' and ''suffix'' can be any of a variety of abbreviations, referring to the kind of file and its contents, like ''bcd'' and ''fits,'' respectively.
The most important MIPS-24 BCD file types for most users will be the *_bcd.fits files for scan mode data and the *_ebcd.fits (enhanced BCD, see section 6.3.4) files for photometry data.
For 70 and 160 microns, there are two important BCD files: *_bcd.fits, and *_fbcd.fits. We currently recommend the application of a median high-pass-filter for scan maps of regions containing faint point sources (*_fbcd.fits), and the standard data reduction (*_bcd.fits) for bright and/or extended sources. (See additional discussion below.)
A complete list of the types for MIPS-24 are listed in Table 6.1, the types for MIPS-70 and MIPS-160 are listed in Table 6.2.
Bit mask definitions for the arrays appear in Table 6.6 for MIPS-24 and Table 6.7 for MIPS-Ge. The bad pixel masks (pmasks) for all the arrays appeared in section 6.5.
