HMI Magnetic Field Products

Synoptic Maps Available

General Description of HMI Magnetic Field Data Products

The line-of-sight magnetic field, hmi.M, is computed from the difference of the Doppler velocities observed in two circular polarizations, as was done for MDI. The filtergrams are obtained by the Doppler camera on HMI. The basic line-of-sight observing cadence is 45 seconds.

The vector magnetic field, hmi.B, is computed from Stokes parameters derived from an independent set of polarized filtergrams. The basic vector field observing cadence is currently 135 seconds and uses HMI's Magnetic camera. Most analysis is done with 720s averages.

The possibility of combining filtergrams from the two cameras will be explored.

Vector field data products include the following quantities (and at least 23 others, including uncertainties)

Data will be exported in a variety of coordinate systems: [Bx,By,Bz], [B_total,gamma,phi], and [Br,Btheta,Bphi]

More detail is provided at VectorMagneticField and LineofsightMagneticField and SpaceWeatherProducts.

Selected HMI Science Data Products

Standard Pipeline

On Demand

On Request