2010年7月13日 · HMI provides four main types of data: dopplergrams (maps of solar surface velocity), continuum filtergrams (broad-wavelength photographs of the solar photosphere), and both line-of-sight and vector magnetograms (maps of the photospheric magnetic field).

SDO is designed to help us understand the Sun's influence on Earth and Near-Earth space by studying the solar atmosphere on small scales of space and time and in many wavelengths simultaneously.

Helioseismic and Magnetic Imager (HMI): is one of three instruments aboard the Solar Dynamics Observatory (SDO) designed to study oscillations and the magnetic field at the solar surface.

The Helioseismic and Magnetic Imager is a new and improved version of the Michelson Doppler Imager (MDI) instrument on the Solar and Heliospheric Observatory (SOHO). SOHO is a joint project of the European Space Agency and NASA.

The Helioseismic and Magnetic Imager (HMI) provides full-disk, high-cadence Doppler, intensity, and magnetic images at 1′′ resolution (4096×4096-pixel images) of the solar photosphere, allowing studies of the sources and evolution of activity within the solar interior.

2024年11月26日 · HMI measures the Sun's magnetic field over the entire visible disk with 1 arc second resolution. Magnetograms are available with a cadence of 45s (line-of-sight) and 720s (line-of-sight and vector). Definitive data products are generally available in a few days.

2012年11月20日 · The Helioseismic Magnetic Imager (HMI) aboard the Solar Dynamics Observatory takes a series of images every 45 seconds in a very narrow range of wavelengths in visible light of the solar photosphere. The wavelengths correspond to a region around the 6173 Ångstroms (617.3 nanometers) spectral line of neutral iron (Fe I).