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Machine Learning Algorithms for Improved Thermospheric Density Modeling
2020Accurate estimation and prediction of the thermospheric density is crucial for accurate low Earth orbit prediction. Recently, Reduced-Order Models (ROMs) were developed to obtain accurate quasi-physical dynamic models for the thermospheric density. In this paper we explore the use of deep neural networks and autoencoders to improve the reduced-order ...
Herbert Turner +3 more
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Validation of GOCE densities and evaluation of thermosphere models
Advances in Space Research, 2014Abstract Atmospheric densities from ESA’s GOCE satellite at a mean altitude of 270 km are validated by comparison with predictions from the near real time model HASDM along the GOCE orbit in the time frame 1 November 2009 through 31 May 2012. Except for a scale factor of 1.29, which is due to different aerodynamic models being used in HASDM and GOCE,
S.L. Bruinsma, E. Doornbos, B.R. Bowman
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On thermospheric neutral density and wind estimation
The neutral mass density of the upper thermosphere can be determined by orbit and accelerometer data from Low Earth Orbit (LEO) satellites. Especially the accelerometers of geodetic satellites, measuring the non-gravitational accelerations acting on these satellites, are a very useful observation for precise density estimation also on very short time ...Florian Wöske +2 more
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Semi-annual Variation in Thermospheric Density
Nature, 1968KING-HELE1 has reported a semi-annual variation in thermospheric density at about 190 km with a maximum to minimum ratio of 1.45. Cook's hypothesis2 that the semi-annual variation is caused by the modulation of the helium content of the lower thermosphere, originally coined to account for the variation at 1,100 km, clearly cannot be applied to explain ...
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Satellite Aerodynamics and Determination of Thermospheric Density and Wind
AIP Conference Proceedings, 2011At present several satellites for earth gravity field measurement are in low polar orbits. These satellites have slender shapes and are equipped with highly sensitive accelerometer packages. Accelerometer data of these satellites can be used to determine local atmospheric density and winds.
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Quantification of Transient Changes of Thermospheric Neutral Density
2014Abstract : The project objective was to determine how the thermosphere responds to transient energy inputs from solar flares and from magnetospheric coupling at high latitudes. GITM simulations showed that both Poynting flux and soft electron precipitation are important in producing neutral density enhancements near 400 km in the cusp observed by the ...
Y. Deng, L. Qian, Arthur D. Richmond
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The “thermospheric spoon”: A mechanism for the semiannual density variation
Journal of Geophysical Research: Space Physics, 1998A mechanism is proposed to explain the cause of the global, semiannual thermospheric density variation. It is suggested that the global‐scale, interhemispheric circulation at solstice acts like a huge turbulent eddy in mixing the major thermospheric species.
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Air density in the lower thermosphere
2nd Annual Meeting, 1965R. POE, H. SMALL
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Thermosphere density from accelerometer and GNSS data
Thermosphere density is one of the largest sources of uncertainty in the orbit estimation and prediction for satellites in low Earth orbit. With the rapidly growing number of satellites in this region, accurate knowledge of thermosphere density is becoming increasingly important for e.g.Jose van den IJssel +4 more
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