SOHO MDI Continuum
MDI measures line-of-sight motion (Dopplergrams), magnetic field (magnetograms), and brightness images in full disk at several resolutions (4 arc-second to very low resolution) and a fixed selected region in higher resolution (1.2 arc-second). MAny data products are available in low level and higher level or processing from raw images to spherical harmonic amplitudes of velocity. Some high level products available directly on the web include maps of a proxy for magnetic activity on the farside of the Sun.
See active regions and coronal holes of the Sun.
SOHO is a project of international cooperation between ESA and NASA