Results 11 to 20 of about 107,756 (305)

Low Earth Orbiting (LEO) Satellite and Orbital Decay

International Journal of Engineering and Advanced Technology, 2022
In this article we present a simple but elegant numerical calculation to study the motion of a low earth orbiting (LEO) satellite in gravitational potential and under the influence of quadratic drag force. We solve a set of coupled differential equations to calculate the instantaneous position and velocity of the satellite and calculate the change in ...
openaire   +1 more source

Extension of the sun-synchronous Orbit [PDF]

, 2010
Through careful consideration of the orbit perturbation force due to the oblate nature of the primary body a secular variation of the ascending node angle of a near-polar orbit can be induced without expulsion of propellant.
Betts J. T., Duesmann B., François Bosquillon de Frescheville, Frerick J., Malcolm Macdonald, Massimiliano Vasile, McKay R., Robert McKay, Roy A. E., Vallado D. A., Vasile M., Vasile M., Wallace N.   +12 more
core   +1 more source

Measuring a Low-Earth-Orbit Satellite Network

2023 IEEE 34th Annual International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC), 2023
Starlink and alike have attracted a lot of attention recently, however, the inner working of these low-earth-orbit (LEO) satellite networks is still largely unknown. This paper presents an ongoing measurement campaign focusing on Starlink, including its satellite access networks, gateway and point-of-presence structures, and backbone and Internet ...
Pan, Jianping, Zhao, Jinwei, Cai, Lin
openaire   +2 more sources

Downlink Coverage and Rate Analysis of Low Earth Orbit Satellite Constellations Using Stochastic Geometry [PDF]

, 2020
As low Earth orbit (LEO) satellite communication systems are gaining increasing popularity, new theoretical methodologies are required to investigate such networks' performance at large.
Angervuori, Ilari, Korpi, Dani, Okati, Niloofar, Riihonen, Taneli, Wichman, Risto   +4 more
core   +2 more sources

Orbit Propagation and Determination of Low Earth Orbit Satellites [PDF]

International Journal of Antennas and Propagation, 2014
This paper represents orbit propagation and determination of low Earth orbit (LEO) satellites. Satellite global positioning system (GPS) configured receiver provides position and velocity measures by navigating filter to get the coordinates of the orbit propagation (OP).
openaire   +2 more sources

A Small Platform for Astrophysical Research Based on the UPM-Sat 1 Satellite of the Universidad Politécnica de Madrid [PDF]

, 2003
UPM-Sat 1 is a small scientific, in-orbit demonstration, educational satellite which has been designed, built, tested, integrated, launched and operated by a team of professors, students, and auxiliary personnel belonging to the Universidad Politécnica ...
A. Sanz-Andrés, Ayuso, González Folgar, González-Folgar, J. Meseguer, J. Santiago-Prowald, J.M. Perales, Sanz-Andrés, Sanz-Andrés   +8 more
core   +2 more sources

The control challenges for the Next Generation Gravity Mission [PDF]

, 2013
Several activities are on going in preparation of a "Next Generation Gravity Mission" (NGGM) aimed at measuring the temporal variations of the Earth gravity field over a long time span with high spatial resolution and high temporal resolution.
Bacchetta, A., Buonocore, M., Canuto, Enrico, Cesare, S., Girouart, B., Massotti, L., Molano Jimenez, A.   +6 more
core   +1 more source

T3P: Demystifying Low-Earth Orbit Satellite Broadband

, 2023
The Internet is going through a massive infrastructural revolution with the advent of low-flying satellite networks, 5/6G, WiFi7, and hollow-core fiber deployments. While these networks could unleash enhanced connectivity and new capabilities, it is critical to understand the performance characteristics to efficiently drive applications over them.
Tiwari, Shubham, Bhushan, Saksham, Taneja, Aryan, Kassem, Mohamed, Luo, Cheng, Zhou, Cong, He, Zhiyuan, Raman, Aravindh, Sastry, Nishanth, Qiu, Lili, Bhattacherjee, Debopam   +10 more
openaire   +2 more sources

Time after time – circadian clocks through the lens of oscillator theory

FEBS Letters, EarlyView.
Oscillator theory bridges physics and circadian biology. Damped oscillators require external drivers, while limit cycles emerge from delayed feedback and nonlinearities. Coupling enables tissue‐level coherence, and entrainment aligns internal clocks with environmental cues.
Marta del Olmo, Carolin Ector, Hanspeter Herzel   +2 more
wiley   +1 more source

The (Glg)ABCs of cyanobacteria: modelling of glycogen synthesis and functional divergence of glycogen synthases in Synechocystis sp. PCC 6803

FEBS Letters, EarlyView.
We reconstituted Synechocystis glycogen synthesis in vitro from purified enzymes and showed that two GlgA isoenzymes produce glycogen with different architectures: GlgA1 yields denser, highly branched glycogen, whereas GlgA2 synthesizes longer, less‐branched chains.
Kenric Lee, Dimitrios Bekiari, Sofia Doello, Karl Forchhammer   +3 more
wiley   +1 more source