SHARP stands for Space-weather HMI Active Region Patch. A SHARP is a DRMS series that contains (1) various space-weather quantities calculated from the photospheric vector magnetogram data and stored as FITS header keywords, and (2) 31 data segments (described in detail below), including each component of the vector magnetic field, the line-of-sight magnetic field, continuum intensity, doppler velocity, error maps and bitmaps. The data segments are not full-disk; rather, they are partial-disk, automatically-identified active region patches. SHARPs are calculated every 12 minutes. Often, there is more than one active region on the solar disk at any given time. Thus, SHARPs are indexed by two prime keys: time, T_REC, and HMI Active Region Patch Number, HARPNUM.
The hmi.sharp_720s_cea_nrt and hmi.sharp_cea_720s data have been projected and remapped to a Cylindrical Equal Area (CEA) Cartesian coordinate system centered on the tracked active region. The size of the nrt regions will evolve with time. At each time step the definitive SHARPs will enclose the maximum extent of the region during it's disk passage. The three prime vector components are Bx, By, and Bz. HARP maps of 8 additional quantities are also provided at each time step: the three estimated component errors, the line-of-sight magnetogram, a Dopplergram, the continuum intensity, a map of the active pixels, and an estimate of the confidence in the disambiguation.