Results 21 to 30 of about 795 (205)

The Earth-Moon Transfer Trajectory Design and Analysis using Intermediate Loop Orbits [PDF]

Journal of Astronomy and Space Sciences, 2009
Various Earth-Moon transfer trajectories are designed and analyzed to prepare the future Korea's Lunar missions. Minimum fuel trajectory solutions are obtained for the departure year of 2017, 2020, 2022, and every required mission phases are analyzed ...
Young-Joo Song, Jin Woo, Sang-Young Park, Kyu-Hong Choi, Eun-Sup Sim   +4 more
doaj   +1 more source

Performance Comparison of the Batch Filter Based on the Unscented Transformation and Other Batch Filters for Satellite Orbit Determination [PDF]

Journal of Astronomy and Space Sciences, 2009
The main purpose of the current research is to introduce the alternative algorithm of the non-recursive batch filter based on the unscented transformation in which the linearization process is unnecessary.
Eunseo Park, Sang-Young Park, Kyu-Hong Choi   +2 more
doaj   +1 more source

The Thermosphere Is a Drag: The 2022 Starlink Incident and the Threat of Geomagnetic Storms to Low Earth Orbit Space Operations

Space Weather, Volume 21, Issue 3, March 2023., 2023
Abstract On 03 February 2022, SpaceX launched 49 Starlink satellites, 38 of which re‐entered the atmosphere on or about 07 February 2022 due to unexpectedly high atmospheric drag. We use empirical model (NRLMSIS, JB08, and HASDM) outputs as well as solar extreme ultraviolet occultation and high‐fidelity accelerometer data to show that thermospheric ...
T. E. Berger, M. Dominique, G. Lucas, M. Pilinski, V. Ray, R. Sewell, E. K. Sutton, J. P. Thayer, E. Thiemann   +8 more
wiley   +1 more source

Balancing Conditions for the Relativistic Correction Using Lorentz Acceleration

International Journal of Aerospace Engineering, Volume 2023, Issue 1, 2023., 2023
In this work, the average effects of the Lorentz acceleration on the charged spacecraft’s orbit are studied encounter with relativistic correction. The relativistic correction as function of the orbital elements, and may be time, is formulated. Lagrange planetary equations are used to calculate the perturbations due to considered perturbing forces. The
M. A. Yousef, M. I. El-Saftawy, A. Mostafa, Yue Wang   +3 more
wiley   +1 more source

Stellar Source Selections for Image Validation of Earth Observation Satellite [PDF]

Journal of Astronomy and Space Sciences, 2011
A method of stellar source selection for validating the quality of image is investigated for a low Earth orbit optical remote sensing satellite. Image performance of the optical payload needs to be validated after its launch into orbit.
Jiwoong Yu, Sang-Young Park, Dongwook Lim, Dong-Han Lee, Young-Jong Sohn   +4 more
doaj   +1 more source

SAR Altimetry Data as a New Source for Swell Monitoring

Geophysical Research Letters, Volume 49, Issue 7, 16 April 2022., 2022
Abstract This article shows the first spectral analysis of fully‐focused Synthetic Aperture Radar (FFSAR) altimetry data with the objective of studying backscatter modulations caused by swells. Swell waves distort the backscatter in altimetry radargrams by means of velocity and range bunching.
Ourania Altiparmaki, Marcel Kleinherenbrink, Marc Naeije, Cornelis Slobbe, Pieter Visser   +4 more
wiley   +1 more source

Optimal Design of Satellite Constellation Korean Peninsula Regions [PDF]

Journal of Astronomy and Space Sciences, 2008
Designing satellite constellations providing partial coverage of certain regions becomes more important as small low-altitude satellites receives an increasing attention due to its cost-effectiveness analysis.
Nam-Kyun Kim, Sang-Young Park, Young-Rok Kim, Kyu-Hong Choi   +3 more
doaj   +1 more source

Extrapolating Empirical Models of Satellite‐Observed Global Mean Sea Level to Estimate Future Sea Level Change

Earth's Future, Volume 10, Issue 4, April 2022., 2022
Abstract We estimate a quadratic model of climate‐driven global mean sea level (GMSL) change based on the satellite altimetry record (1993–2020), including a rigorous assessment of the errors in the quadratic coefficients. We then extrapolate this model 30 years into the future to 2050 and compute the 90% confidence interval.
R. S. Nerem, T. Frederikse, B. D. Hamlington   +2 more
wiley   +1 more source

Bearing‐only underwater uncooperative target tracking for non‐Gaussian environment using fast particle filter

IET Radar, Sonar &Navigation, Volume 16, Issue 3, Page 501-514, March 2022., 2022
Abstract Bearing‐only tracking of an underwater uncooperative target is essential to defend the sea territory. Considering the influences by uncertain underwater environment, the purpose of this work is to estimate 2‐D locations and velocities of an interested underwater target for non‐Gaussian environment.
Xianghao Hou, Long Yang, Yixin Yang, Jianbo Zhou, Gang Qiao   +4 more
wiley   +1 more source

Bivariate Infinite Series Solution of Kepler’s Equations

Mathematics, 2021
A class of bivariate infinite series solutions of the elliptic and hyperbolic Kepler equations is described, adding to the handful of 1-D series that have been found throughout the centuries.
Daniele Tommasini
doaj   +1 more source