Released on February 21, 2014
The Slit-Jaw Imager (SJI) aboard IRIS (Interface Region Imaging Spectrograph) observes a tiny region of the Sun at an image resolution (0.166 arc-seconds per pixel) almost four times higher than the Solar Dynamics Observatory (SDO) (0.6 arc-seconds per pixel). In addition, IRIS has a narrow slit in the imaging plane (the thin, dark vertical line in the center of the inset) which directs some of the light to a spectrograph which allows solar physicists to determine velocity and temperature of the solar plasma.
In this zoom-in from a full-disk view of the Sun from SDO, the imager is observering the Sun at a wavelength of 133nm (1330 angstroms). The imager field-of-view is moved across the solar disk in four steps, allowing the slit to pass over different regions of the Sun to determine the properties of the plasma.
Note: IRIS and SDO are in very different orbits. You can see samples of the orbits at The 2013 Earth-Orbiting Heliophysics Fleet. IRIS is in a near-Earth orbit, while SDO is much higher at geosynchronous orbit. This difference in camera location creates a small parallax between the images composited from these two cameras.
GCMD keywords can be found on the Internet with the following citation:
Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 184.108.40.206.0