The 2MASS Calibration Scan Extended Source Working Databases (Cal-XSWDB, LMC/SMC Cal-XSWDB) contain 388 columns of information per source entry (most of which is photometry). Because extended sources are much more complicated than point sources, it takes many more parameters to characterize them. Some parameters are required to describe the spatial extent of a source, and many more are required to characterize the photometry. In addition to a number of standard measures of photometry, the Cal-XSWDBs also report the magnitude as measured in a number of different fixed-size apertures. The columns are described in the tables below. We have separated the columns accordingto their basic function and utility.
Photometry algorithms and performance, "Large Aperture Photometry: Profile Fitting, Isophotal & Total Mags," are discussed in Section IV.5e. The information contained in the All-Sky Release Extended Source Catalog (XSC) FAQ and Primer, "How to Use the 2MASS XSC -- FAQ Sheet" (Section II.3b) is directly applicable to the Cal-XSWDBs since the calibration scan data were reduced using the same algorithms as the All-Sky Survey.