Results 111 to 120 of about 753,460 (195)

A New Approach to Compiling Exoatmospheric Target Lists and Quantifying the Ground-based Resources Needed to Vet Them

The Astronomical Journal
Transiting exoplanet atmospheric characterization is currently in a golden age as dozens of exoplanet atmospheres are being studied by NASA’s Hubble and James Webb Space Telescopes.
Jennifer A. Burt, Robert T. Zellem, David R. Ciardi, Shubham Kanodia, Geoffrey Bryden, Tiffany Kataria, Kyle A. Pearson, Jessie L. Christiansen, Charles Beichman, B. J. Fulton, Mark Swain   +10 more
doaj   +1 more source

The NEID Earth Twin Survey. II. Dynamical Masses in Seven High-acceleration Star Systems

The Astronomical Journal
We present a set of companion dynamical masses and orbital parameters of seven star systems from the NEID Earth Twin Survey with significant absolute astrometric accelerations between the epochs of Hipparcos and Gaia.
Mark R. Giovinazzi, Cullen H. Blake, Paul Robertson, Andrea S. J. Lin, Arvind F. Gupta, Suvrath Mahadevan, Jason T. Wright, Daniella Bardalez Gagliuffi, Jiayin Dong, Rachel B. Fernandes, Evan Fitzmaurice, Samuel Halverson, Shubham Kanodia, Sarah E. Logsdon, Jacob K. Luhn, Michael W. McElwain, Andy Monson, Joe P. Ninan, Jayadev Rajagopal, Arpita Roy, Christian Schwab, Gudmundur Stefánsson, Ryan Terrien, Jason D. Eastman, Jonathan Horner, Peter Plavchan, Sharon X. Wang, Maurice L. Wilson, Robert A. Wittenmyer   +28 more
doaj   +1 more source

The Implementation of Precise Point Positioning (PPP): A Comprehensive Review. [PDF]

Sensors (Basel), 2023
Elsheikh M, Iqbal U, Noureldin A, Korenberg M.   +3 more
europepmc   +1 more source

Ephemerides <1484–1506>

Tables of values that give the positions of astronomical objects in the sky at a given time or times. Ephemerides are used for astronomy and astrology. Regiomontanus’ Ephemerides astronomicae became indispensable to the seafarers of his time.

core  

Atmospheric density estimation using satellite precision orbit ephemerides

, 2011
The current atmospheric density models are not capable enough to accurately model the atmospheric density, which varies continuously in the upper atmosphere mainly due to the changes in solar and geomagnetic activity. Inaccurate atmospheric modeling results in erroneous density values that are not accurate enough to calculate the drag estimates acting ...
openaire   +1 more source

BDSet: A First-ever BDS Satellite-based PPP Augmentation Dataset Since 2023. [PDF]

Sci Data
Ouyang C, Shi J, Hou C, Peng W, Guo J, Yao Y.   +5 more
europepmc   +1 more source

Characterization of Pseudorange Errors in Hybrid LEO/MEO PNT System. [PDF]

Sensors (Basel)
Bianconi A, Morandi O, Morosi S, Dolfi M.   +3 more
europepmc   +1 more source

Revisiting filtering of two-line element sets for higher precision ephemerides

The availability of accurate and timely state predictions for objects in near-Earth orbits is becoming increasingly important due to the growing congestion in key orbital regimes. The Two-line Element Set (TLE) catalogue remains, to this day, one of the few publicly- available, comprehensive sources of near-Earth object ephemerides.
Hallgarten La Casta, Max, Amato, Davide
openaire   +1 more source

Geodetic Investigations of the Europa Clipper Mission. [PDF]

Space Sci Rev
Steinbrügge G, Park RS, Roberts JH, Bland M, Brooks S, Castillo-Rogez J, Cascioli G, Genova A, Greathouse T, Hussmann H, Kirk R, Magnanini A, Mazarico E, Nimmo F, Park MS, Petricca F, Retherford K, Schroeder DM, Soderlund KM, Tortora P, Zannoni M.   +20 more
europepmc   +1 more source

Angles-Only Navigation via Optical Satellite Measurement with Prior Altitude Constrained. [PDF]

Sensors (Basel)
Dai D, Ni Y, Yu Y, Li J, Qin S.
europepmc   +1 more source