CHAMP mission status

Reigber, Ch.; Lühr, H.; Schwintzer, P.

doi:10.1016/s0273-1177(02)00276-4

Cited by 744 publications

(504 citation statements)

References 0 publications

Supporting

Mentioning

498

Contrasting

Unclassified

Order By: Relevance

“…The CHAMP satellite was launched into a near-circular orbit with an inclination of 87.3°o n 15 July 2000 (Reigber et al 2002;Lühr et al 2004). The high inclination ensures almost complete latitudinal coverage from pole to pole.…”

Section: Champ Neutral Density Datamentioning

confidence: 99%

Thermospheric Density: An Overview of Temporal and Spatial Variations

2011

View full text Add to dashboard Cite

Neutral density shows complicated temporal and spatial variations driven by external forcing of the thermosphere/ionosphere system, internal dynamics, and thermosphere and ionosphere coupling. Temporal variations include abrupt changes with a time scale of minutes to hours, diurnal variation, multi-day variation, solar-rotational variation, annual/semiannual variation, solar-cycle variation, and long-term trends with a time scale of decades. Spatial variations include latitudinal and longitudinal variations, as well as variation with altitude. Atmospheric drag on satellites varies strongly as a function of thermospheric mass density. Errors in estimating density cause orbit prediction error, and impact satellite operations including accurate catalog maintenance, collision avoidance for manned and unmanned space flight, and re-entry prediction. In this paper, we summarize and discuss these density variations, their magnitudes, and their forcing mechanisms, using neutral density data sets and modeling results. The neutral density data sets include neutral density observed by the accelerometers onboard the Challenging Mini-satellite Payload (CHAMP), neutral density at satellite perigees, and global-mean neutral density derived from thousands of orbiting objects. Modeling results are from the National Center for Atmospheric Research (NCAR) thermosphere-ionosphere-electrodynamics general circulation model (TIE-GCM), and from the NRLMSISE-00 empirical model.

show abstract

Section: Champ Neutral Density Datamentioning

confidence: 99%

Thermospheric Density: An Overview of Temporal and Spatial Variations

2011

View full text Add to dashboard Cite

show abstract

“…[26] We use accelerometer measurements of satellite drag from the polar-orbiting low-altitude CHAMP satellite [Reigber et al, 2002] to provide estimates of the in situ total mass density. The CHAMP satellite was originally launched on 15 July 2000 into a high inclination orbit of 87.3 at an altitude of approximately 450 km.…”

Section: Champ Satellite Measurementsmentioning

confidence: 99%

Thermospheric atomic oxygen density estimates using the EISCAT Svalbard Radar

et al. 2013

View full text Add to dashboard Cite

[1] Coupling between the ionized and neutral atmosphere through particle collisions allows an indirect study of the neutral atmosphere through measurements of ionospheric plasma parameters. We estimate the neutral density of the upper thermosphere above~250 km with the European Incoherent Scatter Svalbard Radar (ESR) using the year-long operations of the International Polar Year from March 2007 to February 2008. The simplified momentum equation for atomic oxygen ions is used for field-aligned motion in the steady state, taking into account the opposing forces of plasma pressure gradients and gravity only. This restricts the technique to quiet geomagnetic periods, which applies to most of the International Polar Year during the recent very quiet solar minimum. The method works best in the height rangẽ 300-400 km where our assumptions are satisfied. Differences between Mass Spectrometer and Incoherent Scatter and ESR estimates are found to vary with altitude, season, and magnetic disturbance, with the largest discrepancies during the winter months. A total of 9 out of 10 in situ passes by the CHAMP satellite above Svalbard at 350 km altitude agree with the ESR neutral density estimates to within the error bars of the measurements during quiet geomagnetic periods.

show abstract

“…Vertical incidence sounding and UTL data are still required for the reconstruction purposes. The method has been tested with GPS TEC measurements from the German LEO satellite CHAMP, which has been launched on 15 July 2000, into a circular and polar orbit (inclination = 87°) at an initial altitude of 454 km [Reigber et al, 2000]. Some exemplary calculations are given in Figure 11 for both nighttime and daytime conditions.…”

Section: Application: Reconstruction Of the Electron Density Distribumentioning

confidence: 99%

A new method for reconstruction of the vertical electron density distribution in the upper ionosphere and plasmasphere

et al. 2003

View full text Add to dashboard Cite

[1] Ground-based ionosphere sounding measurements alone are incapable of reliably modeling the topside electron density distribution above the F layer peak density height. Such information can be derived from Global Positioning System (GPS)-based total electron content (TEC) measurements. A novel technique is presented for retrieving the electron density height profile from three types of measurements: ionosonde ( f o F 2 , f o E, M 3000 F 2 , h m f 2 ), TEC (GPS-based), and O + -H + ion transition level. The method employs new formulae based on Chapman, sech-squared, and exponential ionosphere profilers to construct a system of equations, the solution of which system provides the unknown ion scale heights, sufficient to construct a unique electron density profile at the site of measurements. All formulae are based on the assumption of diffusive equilibrium with constant scale height for each ion species. The presented technique is most suitable for middle-and high-geomagnetic latitudes and possible applications include: development, evaluation, and improvement of theoretical and empirical ionospheric models, development of similar reconstruction methods utilizing low-earth-orbiting satellite measurements of TEC, operational reconstruction of the electron density on a real-time basis, etc.

show abstract

CHAMP mission status

Cited by 744 publications

References 0 publications

Thermospheric Density: An Overview of Temporal and Spatial Variations

Thermospheric Density: An Overview of Temporal and Spatial Variations

Thermospheric atomic oxygen density estimates using the EISCAT Svalbard Radar

A new method for reconstruction of the vertical electron density distribution in the upper ionosphere and plasmasphere

Contact Info

Product

Resources

About