&lt;title&gt;Design and performance of the Global Ultraviolet Imager (GUVI)&lt;/title&gt;

Humm, D. C.; Paxton, L. J.; Christensen, A. B.; Ogorzalek, Bernard S.; Pardoe, C. T.; Meng, C.‐I.; Morrison, D.; Strickland, D. J.; Evans, J. S.; Weiss, Michele B.; Crain, William R.; Lew, Patricia H.; Mabry, D. J.; Goldsten, J.; Gary, Stephen A.; Peacock, Keith; Persons, David F.; Harold, Mark J.; Alvarez, E. Brian; Ercol, Carl J.

doi:10.1117/12.330325

Cited by 25 publications

(19 citation statements)

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“… Sagawa et al [2005] found that this wave number‐4 longitudinal signature could not be explained by magnetic declination, F region wind, magnetic field strength or the offset between magnetic and geographic equators and cited lower atmosphere‐ionosphere coupling via nonmigrating tides as a possible explanation. Measurements from equinox 2002 (March, April, September, and October) reported by Henderson et al [2005a], using the same emission line observed by TIMED GUVI [ Humm et al , 1998; Paxton et al , 1999; Christensen et al , 2003] show a clear wave number‐4 signature in the brightness and offset from the magnetic equator of the northern airglow arc, which was also mirrored in the in the offset of the southern arc, although the longitudinal dependence of the brightness of the southern arc did not show this signature. Good symmetry between the northern and southern arcs during these time periods supports the theory that the equatorial fountain was the major factor controlling equatorial F region plasma densities during the spring equinox 2002 as suggest by Sagawa et al [2005].…”

Section: Introductionmentioning

confidence: 74%

Effect of atmospheric tides on the morphology of the quiet time, postsunset equatorial ionospheric anomaly

England¹,

Immel²,

Sagawa³

et al. 2006

J. Geophys. Res.

115

133

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[1] Recent global-scale observations of the postsunset equatorial O + airglow bands in the F region ionosphere using the IMAGE FUV and TIMED GUVI have revealed a longitudinal wave number four pattern in the magnetic latitude and concentration of the F region peak ion density when measured at a fixed local time. In a new comparison of two data sets with observations made by the OGO 4 satellite, this pattern is seen to be persistent over many days around equinox during magnetically quiet conditions close to solar maximum but can be dominated by other processes such as cross-equator winds during other periods. It is found that the longitudinal variability is created by a processes occurring in the dayside ionosphere. A longitudinal modulation of the dayside equatorial fountain is the most likely driving mechanism. Through comparison with GWSM-02 model, it is shown that the predicted modulation of the dayside thermospheric winds and temperatures at E region altitudes created by non-migrating diurnal tides can explain the modulation in the dayside equatorial fountain. This result highlights the importance of understanding the temporal variability of tropospheric weather systems on our understanding and possible predictability of the development of the F region ionosphere. It may also provide a possible further means of testing our understanding of atmospheric tides on a global scale.

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Section: Introductionmentioning

confidence: 74%

Effect of atmospheric tides on the morphology of the quiet time, postsunset equatorial ionospheric anomaly

England¹,

Immel²,

Sagawa³

et al. 2006

J. Geophys. Res.

115

133

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“…The TIMED orbit allows global coverage of the ionosphere with each orbit occurring with a local time about one minute earlier than the previous one, covering all local times every 60 days. The sensitivity of the GUVI instrument at 1356 Å is approximately 0.5 counts/sec/Rayleigh/pixel [ Humm et al , 1998]. The detector array has 14 spatial elements and 160 spectral elements, with selected spectral elements downlinked as “colors”.…”

Section: Guvi Instrumentmentioning

confidence: 99%

A tomographic model for ionospheric imaging with the Global Ultraviolet Imager

2007

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[1] A tomographic forward and inverse model is presented that enables the recovery of three-dimensional ionospheric structures from space-based optical observations. In this paper we apply the technique to the Global Ultraviolet Imager (GUVI) on board the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite. The forward model is based on GUVI observation geometry to simulate radiance observations of a model ionosphere. This model incorporates the physics of the 1356 Å emission and the pattern of line-of-sight measurements out of the plane of the orbit into a discrete matrix representation of the GUVI observation. The application of matrix inversion techniques to the discrete observation matrix allows a multidimensional electron density profile to be reconstructed from the GUVI brightness measurements. Appropriate regularization functionals are incorporated to constrain the reconstructed solution. A smoothness constraint with a nonconvex penalty function ensures smoothness while preserving edges in the reconstructed image, an attribute which is crucial for the reconstruction of sharp ionospheric gradients. Results using GUVI data are shown to demonstrate the applicability of this technique.

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“…The GUVI is an important element of NASA's TIMED mission and simultaneously produces monochromatic images at five colors (HI 121.6‐nm, O I 130.4‐nm, O I 135.6‐nm, N 2 Lyman‐Birge‐Hopfield (LBH) bands from 140.0 to 150.0‐nm and from 165.0 to 180.0‐nm) as its field‐of‐view scans from horizon to the horizon [ Humm et al , 1998; Goldsten et al , 1999; Paxton et al , 1999]. The along‐track field‐of‐view is binned into 14 spatial pixels and its cross‐track scans are divided into 159 steps across the Earth's disk from horizon to horizon and 32 steps of limb scan.…”

Section: Data Presentationmentioning

confidence: 99%

The first coordinated ground‐ and space‐based optical observations of equatorial plasma bubbles

Kelley

Makela

Paxton

et al. 2003

Geophysical Research Letters

Self Cite

114

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[1] We report on ionospheric optical emissions detected by the GUVI instrument on the TIMED satellite. As the satellite crosses the equatorial zone the bright Appleton Anomaly region is imaged. Often these bright zones are interrupted by regions slanted from west to east as the equator is approached forming a backwards 'C'-shape in the image. To explain this feature we use simultaneous ground-based observations looking equatorward from Hawaii using the 777.4-nm emission. We also compare these optical observations to inverted electron density maps, as well as to those made by radar and to numerical simulations of the Rayleigh-Taylor instability. The characteristic shape is a result of a shear in the eastward plasma flow velocity, which peaks near the F peak at the equator and decreases both above and below that height. The ability to detect these unstable and usually turbulent ionospheric regions from orbit provides a powerful global remote sensing capability for an important space weather process.

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<title>Design and performance of the Global Ultraviolet Imager (GUVI)</title>

Cited by 25 publications

References 0 publications

Effect of atmospheric tides on the morphology of the quiet time, postsunset equatorial ionospheric anomaly

Effect of atmospheric tides on the morphology of the quiet time, postsunset equatorial ionospheric anomaly

A tomographic model for ionospheric imaging with the Global Ultraviolet Imager

The first coordinated ground‐ and space‐based optical observations of equatorial plasma bubbles

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