Results 21 to 30 of about 4,818 (307)

Universal adaptive control of satellite formation flying [PDF]

, 2005
In this paper, a new universal adaptive control scheme for satellite formation flying is developed. The underline idea of our design is to combine the domination design and the monotone adaptive gain.
Pongvthithum, R., Veres, S.M., Rogers, E., Gabriel, S.B.   +3 more
core   +1 more source

Thermospheric Neutral Density Variation During the “SpaceX” Storm: Implications From Physics‐Based Whole Geospace Modeling

Space Weather, 2022
The Starlink satellites launched on 3 February 2022 were lost before they fully arrived in their designated orbits. The loss was attributed to two moderate geomagnetic storms that occurred consecutively on 3–4 February.
Dong Lin, Wenbin Wang, Katherine Garcia‐Sage, Jia Yue, Viacheslav Merkin, Joseph M. McInerney, Kevin Pham, Kareem Sorathia   +7 more
doaj   +1 more source

Analysis of Orbital Atmospheric Density from QQ-Satellite Precision Orbits Based on GNSS Observations

Remote Sensing, 2022
Atmospheric drag provides an indirect approach for evaluating atmospheric mass density, which can be derived from the Precise Orbit Determination (POD) of Low Earth Orbit (LEO) satellites. A method was developed to estimate nongravitational acceleration,
Yueqiang Sun, Bowen Wang, Xiangguang Meng, Xinchun Tang, Feng Yan, Xianguo Zhang, Weihua Bai, Qifei Du, Xianyi Wang, Yuerong Cai, Bibo Guo, Shilong Wei, Hao Qiao, Peng Hu, Yongping Li, Xinyue Wang   +15 more
doaj   +1 more source

Global Variations in the Time Delays Between Polar Ionospheric Heating and the Neutral Density Response

Space Weather, 2023
We present results from a study of the time lags between changes in the energy flow into the polar regions and the response of the thermosphere to the heating.
Daniel R. Weimer, Piyush M. Mehta, R. J. Licata, W. K. Tobiska   +3 more
doaj   +1 more source

Fuel Optimization for Low Earth Orbit Maintenance [PDF]

Journal of Astronomy and Space Sciences, 2008
The resolution of Earth images taken from a satellite has close relation with satellite's altitude. If a satellite has lower altitude, it gets a picture having better resolution.
Yong Jae Park, Sang-Young Park, Young-Rok Kim, Kyu-Hong Choi   +3 more
doaj   +1 more source

Rarefied gas effects on the aerodynamics of high area-to-mass ratio spacecraft in orbit [PDF]

, 2013
The aerodynamic situation of a satellite-on-a-chip operating in low Earth orbit bears some resemblance to a classical Crookes radiometer. The large area-to-mass ratio characteristic of a SpaceChip means that very small surface-dependent forces produce ...
Reese, Jason M., White, Craig, Colombo, Camilla, Scanlon, Thomas J., McInnes, Colin, Scanlon, Thomas, Reese, Jason, McInnes, Colin R.   +7 more
core   +1 more source

Impact of Variable Atmospheric and Oceanic Form Drag on Simulations of Arctic Sea Ice [PDF]

, 2014
Over Arctic sea ice, pressure ridges and floe and melt pond edges all introduce discrete obstructions to the flow of air or water past the ice and are a source of form drag.
Laxon, Seymour W., Farell, Sinead, Bacon, Sheldon, Schroeder, David, Kurtz, Nathan, Flocco, Daniela, Feltham, Daniel L., Tsamados, Michel, Farrell, Sinead L., Flocco, Dani, Feltham, Danny, Laxon, Seymour   +11 more
core   +1 more source

Storm time neutral density assimilation in the thermosphere ionosphere with TIDA

Journal of Space Weather and Space Climate, 2022
To improve Thermosphere–Ionosphere modeling during disturbed conditions, data assimilation schemes that can account for the large and fast-moving gradients moving through the modeled domain are necessary.
Codrescu Mihail V., Codrescu Stefan M., Fedrizzi Mariangel   +2 more
doaj   +1 more source

Peak-Seeking Controller for Real-Time Mobile Satellite Tracking [PDF]

, 2012
Increasingly tightened restrictions on antenna beam-width force the use of higher performance hardware in gimbaled satellite communication transceivers. The need for more precise hardware is forcing the price of gimbal-mounted satellites antennas higher.
Karol, Robert Frederick
core   +1 more source

Thermospheric mass density measurement from precise orbit ephemeris

Geodesy and Geodynamics, 2016
Atmospheric drag, which can be inferred from orbit information of low-Earth orbiting (LEO) satellites, provides a direct means of measuring mass density.
Junyu Chen, Jizhang Sang
doaj   +1 more source