Browsing by Author "Freeland, S."

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Instrument Calibration of the Interface Region Imaging Spectrograph (IRIS) Mission
(2018-11) Wulser, J. P.; Jaeggli, Sarah A.; De Pontieu, Bart; Tarbell, Ted D.; Boerner, P.; Freeland, S.; Liu, W.; Timmons, R.; Brannon, Sean R.; Kankelborg, Charles; Madsen, C.; McKillop, Sean; Prchlik, J.; Saar, Steven; Schanche, N.; Bryans, P.; Wiesmann, M.
The Interface Region Imaging Spectrograph (IRIS) is a NASA small explorer mission that provides high-resolution spectra and images of the Sun in the 133-141nm and 278-283nm wavelength bands. The IRIS data are archived in calibrated form and made available to the public within seven days of observing. The calibrations applied to the data include dark correction, scattered light and background correction, flat fielding, geometric distortion correction, and wavelength calibration. In addition, the IRIS team has calibrated the IRIS absolute throughput as a function of wavelength and has been tracking throughput changes over the course of the mission. As a resource for the IRIS data user, this article describes the details of these calibrations as they have evolved over the first few years of the mission. References to online documentation provide access to additional information and future updates.
The Interface Region Imaging Spectrograph (IRIS)
(2014-02) De Pontieu, Bart; Title, Alan M.; Lemen, James; Kushner, G.D.; Akin, D.J.; Allard, A.; Berger, T.; Boerner, P.; Cheung, M.; Chou, C.; Drake, J.F.; Duncan, D.W.; Freeland, S.; Heyman, G.F.; Hoffman, C.; Hurlburt, Neal E.; Lindgren, R.W.; Mathur, D.; Rehse, R.; Sabolish, D.; Seguin, R.; Schrijver, C.J.; Tarbell, Ted D.; Wülser, J.P.; Wolfson, C.J.; Yanari, C.; Mudge, J.; Nguyen-Phuc, N.; Timmons, R.; van Bezooijen, R.; Weingrod, I.; Brookner, R.; Butcher, G.; Dougherty, B.; Eder, J.; Knagenhjelm, V.; Larsen, S.; Mansir, D.; Phan, L.; Boyle, P.; Cheimets, P.N.; DeLuca, E.E.; Golub, Leon; Gates, R.; Hertz, E.; McKillop, Sean; Park, Saehan; Perry, T.; Podgorski, W.A.; Reeves, Kathy K.; Saar, Steven; Testa, Paola; Tian, Hui; Weber, Mark A.; Dunn, C.; Eccles, S.; Jaeggli, Sarah; Kankelborg, Charles; Mashburn, K.; Pust, Nathan J.; Springer, Larry
The Interface Region Imaging Spectrograph (IRIS) small explorer spacecraft provides simultaneous spectra and images of the photosphere, chromosphere, transition region, and corona with 0.33 0.4 arcsec spatial resolution, twosecond temporal resolution, and 1 km s1 velocity resolution over a fieldofview of up to 175 arcsec × 175 arcsec. IRIS was launched into a Sunsynchronous orbit on 27 June 2013 using a PegasusXL rocket and consists of a 19cm UV telescope that feeds a slitbased dualbandpass imaging spectrograph. IRIS obtains spectra in passbands from 1332 1358 Å, 1389 1407 Å, and 2783 2834 Å, including bright spectral lines formed in the chromosphere (Mg ii h 2803 Å and Mg ii k 2796 Å) and transition region (C ii 1334/1335 Å and Si iv 1394/1403 Å). Slitjaw images in four different passbands (C ii 1330, Si iv 1400, Mg ii k 2796, and Mg ii wing 2830 Å) can be taken simultaneously with spectral rasters that sample regions up to 130 arcsec × 175 arcsec at a variety of spatial samplings (from 0.33 arcsec and up). IRIS is sensitive to emission from plasma at temperatures between 5000 K and 10 MK and will advance our understanding of the flow of mass and energy through an interface region, formed by the chromosphere and transition region, between the photosphere and corona. This highly structured and dynamic region not only acts as the conduit of all mass and energy feeding into the corona and solar wind, it also requires an order of magnitude more energy to heat than the corona and solar wind combined. The IRIS investigation includes a strong numerical modeling component based on advanced radiativeMHD codes to facilitate interpretation of observations of this complex region. Approximately eight Gbytes of data (after compression) are acquired by IRIS each day and made available for unrestricted use within a few days of the observation.