Results 71 to 80 of about 22,697 (311)

Precise Orbit Determination for the TerraSAR-X Mission

, 2006
The TerraSAR-X synthetic aperture radar mission relies exclusively on GPS tracking for a precise post-facto orbit reconstruction. Besides a redundant MosaicGNSS single-frequency receiver, the satellite carries the Integrated GPS Occultation Receiver ...
Gill, Eberhard, Garcia-Fernandez, Miquel, Montenbruck, Oliver, Yoon, Yoke   +3 more
core  

COSMIC-2 Precise Orbit Determination [PDF]

, 2019
We present initial results for post-processed GNSS orbit and clock estimation for the FORMOSAT-7/COSMIC-2 (Constellation Observing System for Meteorology, Ionosphere, and Climate) constellation.
Arnold, Daniel, VanHove, Teresa, Weiss, Jan P., Schreiner, Bill, Hunt, Doug, Jäggi, Adrian   +5 more
core  

Precise orbit determination for representative near-Earth asteroids based on optical observations of ground-based stations and the Earth-Moon L1 point’s orbit

Geo-spatial Information Science
Precise orbit determination of near-Earth asteroids (NEAs) provides a critical foundation for exploration missions. Considering that cislunar space is a critical domain for future human space activities and the unique positional advantage of the Earth ...
Zhenqi Wang, Jianguo Yan, Wutong Gao, Shangbiao Sun, Zhen Wang, Wanling Yang, Hakim Saibi, Jean-Pierre Barriot   +7 more
doaj   +1 more source

Organizing the interface—Plasma membrane architecture and receptor dynamics in virus‐cell interactions

FEBS Letters, EarlyView.
Plasma membranes contain dynamic nanoscale domains that organize lipids and receptors. Because viruses operate at similar scales, this architecture shapes early infection steps, including attachment, receptor engagement, and entry. Using influenza A virus and HIV‐1 as examples, we highlight how receptor nanoclusters, multivalent glycan interactions ...
Jan Schlegel, Christian Sieben
wiley   +1 more source

Best hypotheses search on iso-energy-grid for initial orbit determination and track association

, 2013
Debris populating the geostationary orbit is mainly observed by ground-based optical telescopes. Short measurement arcs, known as tracklets, provide line-of-sight information along with the associated rates of change.
Weigel, Martin, Siminski, Jan, Fiedler, Hauke, Montenbruck, Oliver   +3 more
core  

Epigenetic blind spots – the role of DNA methylation dynamics in stem cell‐based models of embryogenesis

FEBS Letters, EarlyView.
Embryo‐like structures (stembryos) are an innovative tool, but they are hindered by experimental variability and limited developmental potential. DNA methylation is crucial for mammalian development, but its status in stembryo models is poorly characterized.
Sara Canil, Anna Corrà, Annalisa Scapolatiello, Chengxiang Qiu, Gianluca Amadei   +4 more
wiley   +1 more source

Space-Based Orbit Determination Using Passive Optical Measurements in LEO [PDF]

openThe increasing number of artificial objects placed in Low Earth Orbit (LEO) has created the need for improvement in the present Space Surveillance and Tracking (STT) systems, which perform Orbit Determination (OD) to estimate their trajectories ...
CABRERA GARCIA, JUAN FELIPE
core  

Improvement of orbit determination for geostationary satellites with VLBI tracking

, 2011
China's COMPASS satellite navigation system consists of five or more geostationary (GEO) satellites. The roles of GEO satellites are to improve the regional user's positioning accuracy and provide the continuous Radio Determination Satellite Service. The
Shi ShanBin, Wang Hong, Hu XiaoGong, Guo Rui, Huang Yong, Jiang DongRong, Zhang XiuZhong   +6 more
core   +1 more source

High-precision GPS orbit determination by integrating the measurements from regional ground stations and LEO onboard receivers

Satellite Navigation
High-precision Global Navigation Satellite System (GNSS) orbit and clock products are crucial for precise applications. An evenly distributed global network enables continuous tracking for GNSS satellites, while a regional network may result in tracking ...
Kai Li, Chengpan Tang, Shanshi Zhou, Xiaogong Hu, Xuhua Zhou   +4 more
doaj   +1 more source

pH‐mediated activation of the lysosomal arginine sensor SLC38A9

FEBS Letters, EarlyView.
Cells monitor nutrient levels via the lysosomal transporter SLC38A9 to activate the mechanistic target of rapamycin complex 1 (mTORC1). This study reveals that SLC38A9 function is regulated by pH. We identified histidine 544 as a critical pH sensor that undergoes conformational changes to control amino acid efflux from lysosomes; therefore, it ...
Xuelang Mu, Ampon Sae Her, Tamir Gonen
wiley   +1 more source