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The NASA/NSO Spectromagnetograph (SPM) at the National Solar Observatory/Kitt Peak Vacuum Telescope has obtained diachronic, full-disk images of the Sun in photospheric magnetic flux, line-of-sight velocity, continuum intensity, equivalent width, and central line depth from 21 Apr 92 to 19 Nov 92 in Fe I 550.7 nm and from 21 Nov 92 to date in Fe I 868.8 nm. The five daily images are formed from on-line analysis of spatially and spectrally resolved line profiles obtained by scanning the solar image across a long-slit spectrograph and are thus strictly simultaneous and cospatial. We discuss a set of curve-fitting procedures for measuring and removing center-to-limb variations, systematic instrumental effects, and terrestrial atmospheric variations with which we have reduced six months of data from 12 Aug 92 to 3 Feb 93. One major purpose of this analysis is to explore how the spatial structures in the SPM diachronic data relate to variations in total solar irradiance. To reduce the data volume (each day's observation is 32 Mbytes) while retaining flexibility to explore a wide variety of possible criteria for classification of features, we have prepared pairs of 2-D histograms comparing each of the four other variables to magnetic flux as well as coarse but strategically binned 5-D histograms. We compare summary statistics based on preliminary feature classification with solar irradiance data obtained over the same period.
