SHARP Near Real Time data in CCD coordinates.

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.

Note that HARPNUMs in the nrt and defnitive data series will be different.

Total unsigned flux

Mean inclination angle, gamma

Mean value of the total field gradient

Mean value of the vertical field gradient

Mean value of the horizontal field gradient

Mean vertical current density

Total unsigned vertical current

Mean current helicity

Total unsigned current helicity

Absolute value of the net current helicity

Sum of the Absolute Value of the Net Currents Per Polarity

Mean photospheric excess magnetic energy density

Total photospheric magnetic energy density

Percentage of pixels with a mean shear angle greater than 45 degrees

The magnetogram segment contains HARP-sized line-of-sight magnetogram data from the DRMS series hmi.M_720s.

The bitmap segment identifies the pixels located within the smooth bounding curve by labeling each pixel with the following:
1 : weak field outside smooth bounding curve
2 : strong field outside smooth bounding curve
33 : weak field inside smooth bounding curve
34 : strong field inside smooth bounding curve

The dopplergram segment contains HARP-sized dopplergram data from the DRMS series hmi.V_720s.

The dopplergram segment contains HARP-sized dopplergram data from the DRMS series hmi.Ic_720s.

The inclination segment contains the magnetic field inclination with respect to the line-of-sight.

The azimuth segment contains the magnetic field azimuth. Zero corresponds to the up direction of a column of pixels on HMI’s CCD; values increase counter-clockwise.

The field segment contains the magnetic field strength. Currently, the filling factor is equal to unity, so this quantity is representative of the magnetic flux density. It is hard to give a single 'uncertainly' value because of the difference in noise between the line-of-sight and transverse field components. Values of 220 Mx/cm2 or less are generally considered to be noise.

The vlos_mag segment contains the velocity of the plasma along the line-of-sight. Positive means redshift. [Note: These data are in cm/s, whereas the dopplergram data are in m/s.]

The dop_width segment contains the doppler width of the spectral line, computed as if it were assumed to be a Gaussian.

The eta_0 segment contains the center-to-continuum absorption coefficient.

The damping segment contains the electron dipole oscillation approximated as a simple harmonic oscillator. In the current version of the code, this parameter is constant and set to 0.5.

The src_continuum segment contains the source function at the base of the photosphere. In the Milne-Eddington approximation, the source function varies linearly with optical depth.

The src_grad segment contains gradient of the source function with optical depth. By definition, src_continuum + src_grad = observed continuum intensity.

The segment alpha_mag is defined as the portion of the resolution element that is filled with magnetized plasma. However, in the current version of the code, this parameter is constant and set to unity.

The segment chisq is a measure of how well the profiles are fit in the least squares iteration. Chisq is not normalized.

This is currently not calcuated.

The info_map segment identifies the quality index of the inversion output. The higher bits are filled by the inversion module, while the lower ones are updated during the disambiguation step (see below). The index of the higher bits at each pixel is defined as follows:
0x00000000 : Good pixel, with no severe issue.
0x0[0-6]00000 : Same as the convergence index in CONV_FLAG
0x08000000 : Bad pixel, defined as the same criteria as #5 of CONFID_MAP.
0x10000000 : Low Q or U signal. sqrt((Q_0 + ··· + Q_5)^2 + (U_0 + ··· + U_5)^2) was smaller than 0.206 sqrt(I_0 + ··· + I_5 )
0x20000000 : Low V signal; |V_0| + |V_1| + ··· + |V_5| was smaller than 0.206 sqrt(I_0 + ··· + I_5 )
0x40000000 : Low B_los value. |Blos| from magnetogram algorithm was smaller than 6.2 Gauss.
0x80000000 : Missing data

The confid_map segment identifies the confidence index of the inversion output. The index value at each pixel will take the integer value from 0 (best) to 6(worst), defined as the highest item number satisfying the following conditions:
0: No issue found in the input Stokes
1: Signals for the transverse field component in the input Stokes parameters (Q & U) were weak.
2: Signal for the line-of-sight field component in the input Stokes parameters (V) was weak.
3: Magnetic field signals of both LoS and transverse component were weak.
4: The ME-VFISV iteration did not converge within the iteration maximum.
In the test data release, we set very small , thus, the confidence ε index at most pixels may be 4.
5: If the difference between the absolute value of the line-of-sight field strength derived from magnetogram algorithm and the absolute value of the LoS component from VFISV inversion |B cos(inclination)| is greater than 500 Gauss, we regard the inversion did not well solve the problem.
6: One (or more) of the 24 input Stokes arrays had NaN value.