  We present an automated system for detecting, tracking, and cataloging
emerging active regions throughout their evolution and decay using SOHO
Michelson Doppler Interferometer (MDI) magnetograms. The SolarMonitor Active
Region Tracking (SMART) algorithm relies on consecutive image differencing to
remove both quiet-Sun and transient magnetic features, and region-growing
techniques to group flux concentrations into classifiable features. We
determine magnetic properties such as region size, total flux, flux imbalance,
flux emergence rate, Schrijver's R-value, R* (a modified version of R), and
Falconer's measurement of non-potentiality. A persistence algorithm is used to
associate developed active regions with emerging flux regions in previous
measurements, and to track regions beyond the limb through multiple solar
rotations. We find that the total number and area of magnetic regions on disk
vary with the sunspot cycle. While sunspot numbers are a proxy to the solar
magnetic field, SMART offers a direct diagnostic of the surface magnetic field
and its variation over timescale of hours to years. SMART will form the basis
of the active region extraction and tracking algorithm for the Heliophysics
Integrated Observatory (HELIO).
