Bibliography

Dynamic gas-surface interaction modeling for satellite aerodynamic computations

Drag coefficients are a large source of uncertainty when predicting the aerodynamic forces on orbiting satellites. Accordingly, the focus of this research is to improve the fidelity of drag modeling by investigating the nature of gas-surface interactions in low earth orbit. The author has investigated to what extent oxygen adsorption can influence the parameters of drag coefficient models, most notably the energy accommodation coefficient.

Pilinski, Marcin;

Published by:       Published on:

YEAR: 2011     DOI:

Drag coefficients of satellites with concave geometries: comparing models and observations

AERONOMIC studies make use of satellite drag measurements in the determination of thermospheric densities, enabling scientific inquiry into processes of the upper neutral

Pilinski, Marcin; Argrow, Brian; Palo, Scott;

Published by: Journal of Spacecraft and Rockets      Published on:

YEAR: 2011     DOI: https://doi.org/10.2514/1.50915

Artificial plasma cave in the low-latitude ionosphere results from the radio occultation inversion of the FORMOSAT-3/COSMIC

Liu, J; Lin, C; Lin, C.; Tsai, H.; Solomon, S.; Sun, Y; Lee, I.; Schreiner, W.; Kuo, Y.;

Published by: Journal of Geophysical Research      Published on: Jan-01-2010

YEAR: 2010     DOI: 10.1029/2009JA015079

Artificial plasma cave in the low-latitude ionosphere results from the radio occultation inversion of the FORMOSAT-3/COSMIC

Liu, J; Lin, C; Lin, C.; Tsai, H.; Solomon, S.; Sun, Y; Lee, I.; Schreiner, W.; Kuo, Y.;

Published by: Journal of Geophysical Research      Published on: Jan-01-2010

YEAR: 2010     DOI: 10.1029/2009JA015079

Dayside ionospheric response to recurrent geomagnetic activity during the extreme solar minimum of 2008

Ram, Tulasi; Lei, J.; Su, S.-Y.; Liu, C.; Lin, C.; Chen, W.;

Published by: Geophysical Research Letters      Published on: Jan-01-2010

YEAR: 2010     DOI: 10.1029/2009GL041038

Radar, lidar, and optical observations in the polar summer mesosphere shortly after a space shuttle launch

Kelley, M.; Nicolls, M.; Varney, R.; Collins, R.; Doe, R.; Plane, J.; Thayer, J.; Taylor, M.; Thurairajah, B.; Mizutani, K.;

Published by: Journal of Geophysical Research      Published on: Jan-01-2010

YEAR: 2010     DOI: 10.1029/2009JA014938

Integrating the Sun-Earth System for the Operational Environment (ISES-OE)

Lean, J.; Huba, J.; McDonald, S.; Slinker, S.; Drob, D.; Emmert, J.; Meier, R.; Picone, J.; Joyce, G.; Krall, J.; Stephan, A.; Roach, K.; Knight, H.; Plunkett, S.; Wu, C.-C.; Wood, B.; Wang, Y.-M.; Howard, R.; Chen, J.; Bernhardt, P.; Fedder, J.;

Published by:       Published on:

YEAR: 2010     DOI:

LWS FST: Determine and Quantify the Responses of Atmospheric/Ionospheric Composition and Temperature to Solar XUV Spectral Variability and Energetic Particles

Talaat, Elsayed; Fuller-Rowell, Tim; Qian, Liying; Richards, Phil; Ridley, Aaron; Burns, Alan; Bernstein, Dennis; Chamberlin, Phillip; Fedrizzi, Mariangel; Hsieh, Syau-Yun; , others;

Published by: 38th COSPAR Scientific Assembly      Published on:

YEAR: 2010     DOI:

Comparison of solar soft X-ray irradiance from broadband photometers to a high spectral resolution rocket observation

Woods, Thomas; Chamberlin, Phillip;

Published by: Advances in Space Research      Published on: Jan-02-2009

YEAR: 2009     DOI: 10.1016/j.asr.2008.10.027

The main ionospheric trough in the East Asian region: Observation and modeling

Pirog, O.M.; Polekh, N.M.; Romanova, E.B.; Tashchilin, A.V.; Zherebtsov, G.A.;

Published by: Journal of Atmospheric and Solar-Terrestrial Physics      Published on: Jan-01-2009

YEAR: 2009     DOI: 10.1016/j.jastp.2008.10.010

Sun-to-Earth Imaging for Operational Space Weather Monitoring

Chua, DH; Wood, BE; Slinker, SP; Meier, RR; Englert, CR; Socker, DG; Huba, J; Krall, J;

Published by:       Published on:

YEAR: 2009     DOI:

Space Shuttle Impacts on Mesospheric Clouds and Iron Layers as Observed by Lidars and Satellites in the Antarctic and Arctic

Chu, X; Collins, RL; Stevens, MH; Plane, JM; Meier, RR; Deland, MT; Kelley, MC; Nicolls, MJ; Thurairajah, B; Varney, RH; , others;

Published by:       Published on:

YEAR: 2009     DOI:

The Ionospheric Mid-Latitude Summer Nighttime Anomaly

This paper presents monthly variations of the mid-latitude summer nighttime anomaly (MSNA) of the ionosphere for the first time by using global observations of the FORMOSAT-3/COSMIC (F3/C), NASA TIMED-GUVI, ground-based radars and GPS receiver network. The MSNA is characterized by greater nighttime (19:00 LT - 24:00 LT, or period of larger solar zenith angles) ionospheric electron density than that during daytime (08:00 - 18:00 LT, or period of smaller solar zenith angles) at middle latitudes during solstices. The anomaly shown in the southern hemisphere during December solstice was previously known as the Weddell Sea Anomaly (WSA) occurring around the Antarctica and the nearby Pacific Ocean, while a WSA-like electron density structure also occurs in the northern hemisphere around June solstice. This study demonstrates that the anomalies occurred in both the northern and southern hemispheres share similar character of greater nighttime density. Moreover, the latitude-altitude cross-section plots of the electron density structure show very similar time-varying electron density evolutions of the MSNA. In both hemispheres, the anomalies with similar electron density characteristics and variations caused by the similar mechanism prompts us to name this phenomenon the mid-latitude summer nighttime anomaly.

Lin, C; Chen, C; Hsu, M; Liu, CH; Liu, JG; Burns, AG; Wang, W;

Published by:       Published on:

YEAR: 2009     DOI:

Gyroless-extending the TIMED mission

The TIMED spacecraft is now it its eighth year of a two-year mission, amassing an unprecedented, uninterrupted collection of upper atmospheric data. Over the course of this time, degradation of the gyros has forced the need to allow operation without them. As a result, the attitude estimation algorithms have been enhanced to allow continued operation under gyroless conditions. This paper describes the algorithms implemented to perform attitude estimation with a tracker-only solution, as well as operational issues encountered with a gyroless spacecraft. On-orbit performance is presented, demonstrating the ability to maintain pointing performance requirements with these new algorithms.

Dellinger, Wayne;

Published by:       Published on:

YEAR: 2009     DOI: 10.2514/6.2009-5948

Ionospheric Electron Density Concurrently Derived by TIP and GOX of FORMOSAT-3/COSMIC.

The tiny ion o spheric pho tom e ter (TIP) and GPS occultation ex per i ment (GOX) onboard FORMOSAT-3/COS MIC (F3/C) are em ployed to mea sure the OI 135.6 nm in ten si ties in

Hsu, Mei-Lan; Rajesh, Panthalingal; Liu, Jann-Yenq; Tsai, Lung-Chih; Tsai, Ho-Fang; Lin, Chien-Hung; Dymond, Kenneth; Coker, Clayton; Chua, Damien; Budzien, Scott; , others;

Published by: Terrestrial, Atmospheric \& Oceanic Sciences      Published on:

YEAR: 2009     DOI: 10.3319/TAO.2008.04.24.02(F3C)

Global Ionospheric Structure Imaged by FORMOSAT-3/COSMIC: Early Results.

A new era of study ing the ion o spheric space weather ef fects has come af ter launch of the in no va tive sat el lite con stel la tion, named as Formosa Sat el lite 3 or Con stel la tion Ob

Lin, Chien-Hung; Liu, Jann-Yenq; Hsiao, Chun-Chieh; Liu, Chao-Han; Cheng, Chio-Zong; Chang, Po-Ya; Tsai, Ho-Fang; Fang, Tzu-Wei; Chen, Chia-Hung; Hsu, Mei-Lan;

Published by: Terrestrial, Atmospheric \& Oceanic Sciences      Published on:

YEAR: 2009     DOI:

The Production of Titan’s Far Ultraviolet Nitrogen Airglow

Stevens, Michael; Gustin, Jacques; Ajello, Joseph; Evans, Scott; Meier, RR; Stephan, Andrew; Stewart, Ian; Larsen, Kristopher; Esposito, Larry; McClintock, William;

Published by: Space      Published on:

YEAR: 2009     DOI:

Photoelectron flux variations observed from the FAST satellite

This paper examines high resolution (ΔE/E\ =\ 0.15) photoelectron energy spectra from 10\ eV to 1\ keV, created by solar irradiances between 1.2 and 120\ nm. The observations were made from the FAST satellite at \~3000\ km, equatorward of the auroral oval for the July\textendashAugust, 2002 solar rotation. These data are compared with the solar irradiance observed by the Solar EUV Experiment (SEE) on the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite and fluxes calculated using the Field Line Interhemispheric Plasma (FLIP) code. The 41\ eV photoelectron flux, which corresponds to solar EUV fluxes near 20\ nm, shows a clear solar rotation variation in very good agreement with the EUV flux measurements. This offers the possibility that the 41\ eV photoelectron flux could be used as a check on measured solar EUV fluxes near 20\ nm. Because of unexpected noise, the solar rotation signal is not evident in the integral photoelectron flux between 156 and 1000\ eV corresponding to EUV wavelengths between 0.1 and 7\ nm measured by the SEE instrument. Examination of daily averaged photoelectron fluxes at energies between 25 and 500\ eV show significant changes in the photoelectron spectra in response X and M class flares. The intensity of photoelectrons produced in this energy region is primarily due to two very narrow EUV wavelength regions at 2.3 and 3\ nm driving Auger photoionization in O at 500\ eV and N₂\ at \~360\ eV. Comparison of calculated and daily averaged electron fluxes shows that the HEUVAC model solar spectrum used in the FLIP code does not reproduce the observed variations in photoelectron intensity. In principle, the 21 discrete photoelectron energy channels could be used to improve the reliability of the solar EUV fluxes at 2.3 and 3\ nm inferred from broad band observations. In practice, orbital biases in the way the data were accumulated and/or noise signals arising from natural and anthropogenic longitudinally restricted sources of ionization complicate the application of this technique.

Peterson, W.K.; Woods, T.N.; Chamberlin, P.C.; Richards, P.G.;

Published by: Advances in Space Research      Published on: Jan-09-2008

YEAR: 2008     DOI: 10.1016/j.asr.2007.08.038

Photoelectrons; Solar flares; XUV solar irradiance

XUV Photometer System (XPS): Improved Solar Irradiance Algorithm Using CHIANTI Spectral Models

Woods, Thomas; Chamberlin, Phillip; Peterson, W.; Meier, R.; Richards, Phil; Strickland, Douglas; Lu, Gang; Qian, Liying; Solomon, Stanley; Iijima, B.; Mannucci, A.; Tsurutani, B.;

Published by: Solar Physics      Published on: Jan-08-2008

YEAR: 2008     DOI: 10.1007/s11207-008-9196-6

Global-scale Observations of the Limb and Disk: a key mission for understanding thermosphere-ionosphere forcing

Eastes, R; Burns, AG; McClintock, W; Aksnes, A; Anderson, D; Andersson, L; Budzien, S; Codrescu, M; Daniell, R; England, S; , others;

Published by:       Published on:

YEAR: 2008     DOI:

Low Latitude Ionosphere Measurements by the Global-scale Observations of the Limb and Disk (GOLD) Mission

Eastes, RW; Anderson, DN; McClintock, WE; Aksnes, A; Andersson, L; Burns, AG; Budzien, SA; Codrescu, MV; Daniell, RE; Dymond, KF; , others;

Published by:       Published on:

YEAR: 2008     DOI:

The OI 135.6 nm Observations of the Weddell Sea Anomaly and the Nighttime Mid-Latitude Enhancement

Hsu, M; Liu, J; Lin, C; Tsai, H; Rajesh, P; Paxton, L; Hsu, R; Su, H;

Published by:       Published on:

YEAR: 2008     DOI:

Use of two-line element data for thermosphere neutral density model calibration

Traditional empirical thermospheric density models are widely used in orbit determination and prediction of low-Earth satellites. Unfortunately, these models often exhibit large density errors of up to around 30\% RMS. Density errors translate into orbit errors, adversely affecting applications such as re-entry operations, manoeuvre planning, collision avoidance and precise orbit determination for geodetic missions. The extensive database of two-line element (TLE) orbit data contains a wealth of information on satellite drag, at a sufficiently high spatial and temporal resolution to allow a calibration of existing neutral density models with a latency of one to two days. In our calibration software, new TLE data for selected objects is converted to satellite drag data on a daily basis. The resulting drag data is then used in a daily adjustment of density model calibration parameters, which modify the output of an existing empirical density model with the aim of increasing its accuracy. Two different calibration schemes have been tested using TLE data for about 50 objects during the year 2000. The schemes involve either height-dependent scale factors to the density or corrections to CIRA-72 model temperatures, which affect the density output based on a physical model. Both schemes have been applied with different spherical harmonic expansions of the parameters in latitude and local solar time. Five TLE objects, varying in perigee altitude between 280 and 530km, were deliberately not used during calibration, in order to provide independent validation. Even with a single daily parameter, the RMS density model error along their tracks can already be reduced from the 30% to the 15% level. Adding additional parameters results in RMS errors lower than 12%.

Doornbos, Eelco; Klinkrad, Heiner; Visser, Pieter;

Published by: Advances in Space Research      Published on:

YEAR: 2008     DOI: https://doi.org/10.1016/j.asr.2006.12.025

thermosphere density; satellite drag; Orbit determination; two-line elements

The structure of equatorial ionization anomaly seen by TIMED/GUVI limb observations

Lee, I; Liu, J; Rajesh, P; Lin, C;

Published by:       Published on:

YEAR: 2008     DOI:

Constraining and validating the Oct/Nov 2003 X-class EUV flare enhancements with observations of FUV dayglow and E -region electron densities

Strickland, D.; Lean, J.; Daniell, R.; Knight, H.; Woo, W.; Meier, R.; Straus, P.; Woods, T.; Eparvier, F.; McMullin, D.; Christensen, A.; Morrison, D.; Paxton, L.;

Published by: Journal of Geophysical Research      Published on: Jan-01-2007

YEAR: 2007     DOI: 10.1029/2006JA012074

Longitudinal structure of the equatorial ionosphere: Time evolution of the four-peaked EIA structure

Lin, C.; Hsiao, C.; Liu, J; Liu, C.;

Published by: Journal of Geophysical Research      Published on: Jan-01-2007

YEAR: 2007     DOI: 10.1029/2007JA012455

Motions of the equatorial ionization anomaly crests imaged by FORMOSAT-3/COSMIC

Lin, C.; Liu, J; Fang, T.; Chang, P; Tsai, H.; Chen, C.; Hsiao, C.;

Published by: Geophysical Research Letters      Published on: Jan-01-2007

YEAR: 2007     DOI: 10.1029/2007GL030741

Plausible effect of atmospheric tides on the equatorial ionosphere observed by the FORMOSAT-3/COSMIC: Three-dimensional electron density structures

Lin, C.; Wang, W.; Hagan, M.; Hsiao, C.; Immel, T.; Hsu, M.; Liu, J; Paxton, L.; Fang, T.; Liu, C.;

Published by: Geophysical Research Letters      Published on: Jan-01-2007

YEAR: 2007     DOI: 10.1029/2007GL029265

Global-scale Observations of the Limb and Disk (GOLD)-New Observing Capabilities for Space Weather Specification and Forecasting

Eastes, R; Codrescu, M; McClintock, W; Aksnes, A; Anderson, D; Andersson, L; Burns, A; Budzien, S; Daniell, R; Dymond, K; , others;

Published by:       Published on:

YEAR: 2007     DOI:

Using Satellite Measurements to Evaluate Clouds And Their Seasonal Variations in 10 Atmospheric General Circulation Models

Zhang, M; Lin, W; Klein, S; Backmeister, J; Bony, S; Cederwall, R; Del Genio, A; Hack, J; Loeb, N; Lohmann, U; , others;

Published by:       Published on:

YEAR: 2007     DOI:

Constraining and validating the Oct/Nov 2003 X-class EUV flare enhancements with observations of FUV dayglow and E-region electron densities

Strickland, DJ; Lean, JL; , Daniell; Knight, HK; Woo, WK; Meier, RR; Straus, PR; Woods, TN; Eparvier, FG; McMullin, DR; , others;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2007     DOI:

Correction of SOHO CELIAS/SEM EUV measurements saturated by extreme solar flare events

Didkovsky, LV; Judge, DL; Jones, AR; Wieman, S; Tsurutani, BT; McMullin, D;

Published by: Astronomische Nachrichten: Astronomical Notes      Published on:

YEAR: 2007     DOI:

Atomic oxygen photoionization rates computed with high resolution cross sections and solar fluxes

Meier, RR; McLaughlin, Brendan; Warren, HP; Bishop, James;

Published by: Geophysical research letters      Published on:

YEAR: 2007     DOI:

Photoionization Rate of Atomic Oxygen

Meier, RR; McLaughlin, BM; Warren, HP; Bishop, J;

Published by:       Published on:

YEAR: 2006     DOI:

Global-scale Observations of the Limb and Disk (GOLD): Mission Implementation

McClintock, W; Lankton, M; Estes, R; Aksens, A; Anderson, D; Andersson, L; Codrescu, M; Burns, A; Daniell, R; Eparvier, F; , others;

Published by:       Published on:

YEAR: 2006     DOI:

Response of the Upper/Middle Atmosphere to Coronal Holes

RJ, Niciejewski; Palo\textordmasculine, SE; Paxton, LJ; Randall, CE; Rong\textordmasculine, PP;

Published by: Recurrent Magnetic Storms: Corotating Solar Wind Streams      Published on:

YEAR: 2006     DOI:

Response of the Upper/Middle Atmosphere to Coronal Holes

RJ, Niciejewski; Palo\textordmasculine, SE; Paxton, LJ; Randall, CE; Rong\textordmasculine, PP;

Published by: Recurrent Magnetic Storms: Corotating Solar Wind Streams      Published on:

YEAR: 2006     DOI:

The relationship between TIMED/GUVI and Global GPS-TEC measurements in the equatorial ionization anomaly region

Hsu, M; Liu, J; Lin, C; Tsai, H; Paxton, L; Rajesh, P;

Published by:       Published on:

YEAR: 2006     DOI:

Large-scale variations of the low-latitude ionosphere during the October\textendashNovember 2003 superstorm: Observational results

Lin, C.; Richmond, A.D.; Liu, J.Y.; Yeh, H.C.; Paxton, L.; Lu, G.; Tsai, H.F.; Su, S.-Y.;

Published by: Journal of Geophysical Research      Published on: Jan-01-2005

YEAR: 2005     DOI: 10.1029/2004JA010900

October 2002 30-day incoherent scatter radar experiments at Millstone Hill and Svalbard and simultaneous GUVI/TIMED observations

A long-duration incoherent scatter radar (ISR) experiment was conducted at Millstone Hill and Svalbard from October 4\textendashNovember 4, 2002. Along with the simultaneous GUVI/TIMED neutral composition measurements, this 30-day run enabled us to study a number of thermosphere-ionosphere-magnetosphere phenomena. This paper focuses on the day-to-day variability and quasiperiodic oscillation of the ionosphere. The day-to-day variability under quiet magnetic conditions in electron density Ne, ion temperature Ti and electron temperature Te, respectively, changed with local time and height, with the largest variability in Ne and the smallest in Ti. Midnight through dawn was the period of largest variability. Quasiperiodic Ne oscillations were present with periods \>1 day. Some of these oscillations were correlated with changes in the neutral composition originating from geomagnetic activity, which altered the global atmospheric circulation as a result of high latitude heating processes as indicated in Svalbard ion temperature enhancements. However, the wave-type oscillation of Ne exhibits a downward phase progression which persists up to 600 km and prevails until a large storm appears to impose an upward phase progression.

Zhang, Shun-Rong; Holt, John; Erickson, Phil; Lind, Frank; Foster, John; van Eyken, Anthony; Zhang, Yongliang; Paxton, Larry; Rideout, William; Goncharenko, Larisa; Campbell, Glenn;

Published by: Geophysical Research Letters      Published on: 01/2005

YEAR: 2005     DOI: 10.1029/2004GL020732

The relationship between TIMED/GUVI and Global GPS-TEC measurements in the equatorial ionization anomaly region

Hsu, M; Liu, J; Lin, C; Tsai, H;

Published by:       Published on:

YEAR: 2005     DOI:

Violent Sun-Earth Connection Events of October-November 2003-A09S28-Large-scale variations of the low-latitude ionosphere during the October-November 2003 superstorm

Lin, CH; RichmondJ Y Liu, AD; Yeh, HC; Paxton, LJ; Lu, G; Tsai, HF; Su, SY;

Published by: Journal of Geophysical Research-Part A-Space Physics      Published on:

YEAR: 2005     DOI:

Space Sciences-L01108 October 2002 30-day incoherent scatter radar experiments at Millstone Hill and Svalbard and simultaneous GUVI/TIMED observations (DOI 10.1029/2004GL020732)

Zhang, Shun-Rong; Holt, John; Erickson, Phil; Lind, Frank; Foster, John; van Eyken, Anthony; Zhang, Yongliang; Paxton, Larry; Rideout, William; Goncharenko, Larisa; , others;

Published by: Geophysical Research Letters      Published on:

YEAR: 2005     DOI:

Large-scale variations of the low-latitude ionosphere during the October-–November 2003 superstorm: Observational results

The GPS-derived total electron content (TEC), ion drift measurements from the ROCSAT-1 spacecraft at around 600 km altitude, and far-ultraviolet airglow measured by the Global Ultraviolet Imager (GUVI) carried on board the NASA TIMED satellite are utilized for studying large disturbances of the low-latitude ionosphere during the October–November 2003 superstorm period. Two chains of GPS receivers, one in the American sector (∼70°W) and the other in the Asian/Australian sector (∼120°E), are used to simultaneously observe the daytime equatorial ionization anomaly (EIA) during the entire storm period. It is found from the GPS-TEC measurements that the EIA expanded to very high latitudes with large increases of TEC right after the storm started. The large expansion of the EIA was associated with strong upward E × B drifts measured from the Ionospheric Plasma and Electrodynamics Instrument (IPEI) on board the ROCSAT-1, providing evidence of a penetration electric field and a strong plasma fountain effect. Suppression of the EIA was observed during the storm recovery, associated with downward E × B drifts that were observed by the ROCSAT-1. Significant negative storm effects in the southern hemisphere were also observed in the GPS-TEC during the first day of the recovery phase. The areas of negative storm effects are in good agreement with reductions in the [O]/[N2] density ratio inferred from the ratio of OI (135.6 nm) to LBH emissions measured from GUVI. An enhancement of the EIA was observed on the day, 1 November, that the storm was about to fully recover.

Lin, C.; Richmond, A.; . Y. Liu, J; Yeh, H.; Paxton, L.; Lu, G.; Tsai, H.; Su, S.-Y.;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2005     DOI: https://doi.org/10.1029/2004JA010900

ionospheric disturbances; Magnetic storm; TEC enhancement

Spacecraft Attitude Determination

By spacecraft attitude, we mean how a spacecraft is oriented in space. Every spacecraft carries a complement of instruments, usually called a payload, that must be directed in some way

Shuster, Malcolm; Dellinger, Wayne;

Published by: Fundamentals of Space Systems      Published on:

YEAR: 2005     DOI:

Large-scale variations of the low-latitude ionosphere during the October—November 2003 superstorm: Observational results

Lin, CH; Richmond, AD; Liu, JY; Yeh, HC; Paxton, LJ; Lu, G; Tsai, HF; Su, S-Y;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2005     DOI:

Solar EUV Experiment (SEE): Mission overview and first results

[1]\ The Solar EUV Experiment (SEE) is one of four scientific instruments on the NASA Thermosphere Ionosphere Mesosphere Energetics Dynamics (TIMED) spacecraft, which has been simultaneously observing the Sun and Earth\textquoterights upper atmosphere since January 2002. The SEE instrument measures the irradiance of the highly variable, solar extreme ultraviolet (EUV) radiation, one of the major energy sources for the upper atmosphere. The primary SEE data product is the solar spectral irradiances from 0.1 to 194 nm in 1 nm intervals that are fundamental for the TIMED mission\textquoterights investigation of the energetics in the tenuous, but highly variable, layers of the Earth\textquoterights atmosphere above 60 km. The TIMED mission began normal operations on 22 January 2002, a time when the Sun displayed maximum levels of activity for solar cycle 23, and has provided daily measurements as solar activity has declined to moderate levels. Solar irradiance variability observed by SEE during the 2 years of the TIMED prime mission includes a variety of moderate and large flares over periods of seconds to hours and dozens of solar rotational cycles over a typical period of 27 days. The SEE flare measurements provide important, new results because of the simultaneous spectral coverage from 0.1 to 194 nm, albeit limited temporal coverage due to its 3\% duty cycle. In addition, the SEE measurements reveal important, new results concerning phase shifts of 2\textendash7 days in the intermediate-term variations between different UV wavelengths that appear to be related to their different center-to-limb variations. The new solar EUV irradiance time series from SEE are also important in filling the \textquotedblleftEUV Hole,\textquotedblright which is the gap in irradiance measurements in the EUV spectrum since the 1980s. The solar irradiances measured by SEE (Version 7, released July 2004) are compared with other measurements and predictions from models of the solar EUV irradiance. While the measurement comparisons show reasonable agreement, there are significant differences between SEE and some of the models in the EUV range. The data processing algorithms and calibrations are also discussed.

Woods, Thomas; Eparvier, Francis; Bailey, Scott; Chamberlin, Phillip; Lean, Judith; Rottman, Gary; Solomon, Stanley; Tobiska, Kent; Woodraska, Donald;

Published by: Journal of Geophysical Research: Space Physics (1978\textendash2012)      Published on:

YEAR: 2005     DOI: 10.1029/2004JA010765

thermosphere; solar activity cycle; solar irradiance; ultraviolet emissions; solar effects

Solar irradiance variability during the October 2003 solar storm period

Woods, Thomas; Eparvier, Francis; Fontenla, Juan; Harder, Jerald; Kopp, Greg; McClintock, William; Rottman, Gary; Smiley, Byron; Snow, Martin;

Published by: Geophysical research letters      Published on:

YEAR: 2004     DOI:

Solar EUV irradiance variability derived from terrestrial far ultraviolet dayglow observations

Remotely sensed ultraviolet emissions from the Earth s upper atmosphere are shown to mirror fluctuations in solar EUV irradiance during July 2002, including the overall increase and decrease as the Sun rotated, and episodic increases associated with multiple solar flares. The TIMED/GUVI dayglow observations are used to derive a new quantity, QEUVGUVI, which is a measure of integrated solar EUV electromagnetic energy shortward of 45 nm. Both the absolute QEUVGUVI values and their modulation by solar rotation agree well with the corresponding solar EUV energy estimated by the NRLEUV irradiance variability model. The QEUVGUVI values do not support recent suggestions that the solar EUV irradiances estimated by the model of Hinteregger et al. be increased by a factor of four, nor even a factor of two.

Strickland, D.J.; Lean, J.L.; Meier, R.R.; Christensen, A.B.; Paxton, L.J.; Morrison, D.; Craven, J.D.; Walterscheid, R.L.; Judge, D.L.; McMullin, D.R.;

Published by: Geophysical research letters      Published on:

YEAR: 2004     DOI: 10.1029/2003GL018415

Autonomous satellite navigation system

Devereux, William; Heins, Robert; Chacos, Albert; Linstrom, Lloyd; Asher, Mark; Duven, Dennis; Gruenbacher, Don; Kusterer, Thomas; Strohbehn, Kim; Morgan, Richard; , others;

Published by:       Published on: aug

YEAR: 2003     DOI: