Results 81 to 90 of about 27,737 (204)

SN 2007gr: a Normal Type Ic Supernova with a Mildly Relativistic Radio Jet? [PDF]

, 2010
A nearby type Ic supernova, SN 2007gr was observed with the EVN in two epochs 60 days apart (second observation also included the Green Bank Telescope).
Bourke, Stephen, Campbell, Robert, Garrett, Michael, Granot, J., Horst, A. van der, Kouveliotou, C., Langevelde, H.J. van, Paragi, Zsolt, Pidopryhora, Yurii, Ramirez-Ruiz, Enrico, Tanaka, M, Taylor, G.   +11 more
core  

Advanced relativistic VLBI model for geodesy

, 2016
Our present relativistic part of the geodetic VLBI model for Earthbound antennas is a consensus model which is considered as a standard for processing high-precision VLBI observations. It was created as a compromise between a variety of relativistic VLBI
Han, Wen-Biao, Kopeikin, Sergei, Soffel, Michael   +2 more
core   +1 more source

Studying the Inner Heliosphere Using Radio Signals Transmitted From Spacecraft Orbiting Mars

Space Weather, Volume 23, Issue 5, May 2025.
Abstract In this campaign, we used very long baseline interferometry (VLBI) radio telescopes to track the carrier radio signal transmitted from spacecraft orbiting Mars during the Mars solar conjunction. The campaign extended from September 6th $6\text{th}$ to November 6th $6\text{th}$ 2021 and targeted the Mars Express (MEX) and Tianwen‐1 (TIW ...
J. Edwards, G. Molera Calvés, P. Kummamuru, N. M. M. Said, M. Ma   +4 more
wiley   +1 more source

e-EVN detection of AGN activity in NGC 2617 [PDF]

, 2013
NGC 2617 is a Seyfert 1.8 spiral galaxy at z=0.0142 (~60 Mpc, 1 mas = 0.3 pc) that is currently in outburst.
Komossa, S, Oonk, Raymond, Paragi, Zsolt, van Bemmel, Ilse, Yang, Jun   +4 more
core  

Deep Neural Networks for Refining Vertical Modeling of Global Tropospheric Delay

Geophysical Research Letters, Volume 52, Issue 2, 28 January 2025.
Abstract Kinematic airborne platforms are becoming increasingly vital for Earth observation. They highlight the critical need for accurate tropospheric delay corrections across varying altitudes, especially as most existing models are limited to Earth's surface.
Peng Yuan, Kyriakos Balidakis, Jungang Wang, Pengfei Xia, Jian Wang, Mingyuan Zhang, Weiping Jiang, Harald Schuh, Jens Wickert, Zhiguo Deng   +9 more
wiley   +1 more source

Linking Planetary Ephemeris Reference Frames to ICRF via Millisecond Pulsars

Universe
The positions of millisecond pulsars (MSPs) can be determined with sub-milliarcsecond (mas) accuracy using both Very Long Baseline Interferometry (VLBI) and timing, referenced to the International Celestial Reference Frame (ICRF) and planetary ...
Li Guo, Yueqi Song, Zhen Yan, Liang Li, Guangli Wang   +4 more
doaj   +1 more source

Submicrosecond comparison of international clock synchronization by VLBI and the NTS satellite [PDF]

, 1979
The intercontinental clock synchronization capabilities of Very Long Baseline Interferometry (VLBI) and the Navigation Technology Satellite (NTS) were compared using both methods to synchronize the Cesium clocks at the NASA Deep Space Net complexes at ...
Bussion, J., Hurd, W. J., Mccaskill, T., Oaks, J., Wardrip, S. C., Warren, H., Whitworth, G.   +6 more
core   +1 more source

Role of Barystatic Sea Level Change in Global Mass Conservation and Its Excitation to Length‐Of‐Day Variations

Earth and Space Science, Volume 12, Issue 1, January 2025.
Abstract Barystatic sea level stores excess water mass from the atmosphere and land to maintain global mass conservations within the Earth system. Besides the secular contribution to global sea‐level rise, changes in barystatic sea level also play an important role in mass‐induced length‐of‐day (LOD) variations over a few years or shorter periods ...
Qiqi Shi, Yonghong Zhou, Cancan Xu, Xueqing Xu   +3 more
wiley   +1 more source

Holocene Paleoenvironment Changes Near Lake Funazoko‐Ike, East Antarctica, Based on Analyses of Sediments and Microfossils

Island Arc, Volume 34, Issue 1, January/December 2025.
ABSTRACT Lake Funazoko‐Ike was formed by a relative sea level fall due to crustal uplift after the melting of the ice sheet. Today, the lake surface lies approximately 25 m below the present sea level. Evidence of these processes is recorded in sediments deposited from the sill to the lake surface around Lake Funazoko‐Ike during the middle to late ...
Satoshi Sasaki, Koji Seto, Kota Katsuki
wiley   +1 more source

A Satellite Drift Scan Approach for Establishing the Pointing Model of Radio Telescopes

Advances in Astronomy, Volume 2025, Issue 1, 2025.
In the era of large satellite constellations, there are more than 1000 satellites in orbit. While the signals from these satellites may pose a risk of radio frequency interference (RFI) to radio telescopes, they also present a potential advantage by serving as high‐spatial‐density pointing references for radio telescopes.
Ye Yuan, Zhi-Yong Liu, Na Wang, Hao Yan, Arpan Hazra   +4 more
wiley   +1 more source