edu.ucar.opensky::articles:12040 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-26T04:06:29.450588 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7bz66rh Design and ground calibration of the helioseismic and magnetic imager (HMI) instrument on the solar dynamics observatory 2012-01-01T00:00:00Z publication https://n2t.org/ark:/85065/d7bz66rh https://doi.org/10.1007/s11207-011-9842-2 Schou, J. author Scherrer, P. author Bush, R. author Wachter, R. author Couvidat, S. author Rabello-Soares, M. author Bogart, R. author Hoeksema, J. author Liu, Y. author Duvall, T. author Akin, D. author Allard, B. author Miles, J. author Rairden, R. author Shine, R. author Tarbell, T. author Title, A. author Wolfson, C. author Elmore, David F. author Norton, Aimee author Tomczyk, Steven author UCAR/NCAR - Library publisher The Helioseismic and Magnetic Imager (HMI) investigation (Solar Phys. doi:10.1007/s11207-011-9834-2, 2011) will study the solar interior using helioseismic techniques as well as the magnetic field near the solar surface. The HMI instrument is part of the Solar Dynamics Observatory (SDO) that was launched on 11 February 2010. The instrument is designed to measure the Doppler shift, intensity, and vector magnetic field at the solar photosphere using the 6173 Å Fe I absorption line. The instrument consists of a front-window filter, a telescope, a set of waveplates for polarimetry, an image-stabilization system, a blocking filter, a five-stage Lyot filter with one tunable element, two wide-field tunable Michelson interferometers, a pair of 4096² pixel cameras with independent shutters, and associated electronics. Each camera takes a full-disk image roughly every 3.75 seconds giving an overall cadence of 45 seconds for the Doppler, intensity, and line-of-sight magnetic-field measurements and a slower cadence for the full vector magnetic field. This article describes the design of the HMI instrument and provides an overview of the pre-launch calibration efforts. Overviews of the investigation, details of the calibrations, data handling, and the science analysis are provided in accompanying articles. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication Copyright 2012 Springer. None eng geoscientificInformation