Results 81 to 90 of about 32,900 (194)
The THEMIS Control Network of Mars
Earth and Space Science, Volume 13, Issue 1, January 2026.Abstract The accurate co‐registration of geospatial data is necessary to answer questions that cross‐cut disciplines and are key to understanding fundamental questions about our Solar System. To address this need and provide an updated product for Mars that is tied to a common reference frame, we have photogrammetrically controlled Thermal Emission ...
R. L. Fergason, L. Weller, M. T. Bland
wiley +1 more source
Nimbus 6 Doppler processing using the Fairbanks calibration platform [PDF]
A weighted least squares processor is examined. Research conducted in support of the NASA satellite aided Search and Rescue program is presented. An estimated NIMBUS 6 ephemeris, accurate to 1.5-2.5 km and 0.5-2.5 m/s relative to a reference orbit, is ...
Koch, D. W., Lefler, J. G.
core +1 more source
Journal of Geophysical Research: Space Physics, Volume 131, Issue 1, January 2026.Abstract Earth's outer radiation belt electron flux is highly variable and can be enhanced by over an order of magnitude over timescales less than one day, as observed during the October 2012 storm. Previous studies of this storm (e.g., Reeves et al., 2013, https://doi.org/10.1126/science.1237743) have invoked local acceleration to explain this ...
L. G. Ozeke +4 more
wiley +1 more source
A Search for Hierarchical Triples using Kepler Eclipse Timing
, 2012 We present the first results of a Kepler survey of 41 eclipsing binaries that we undertook to search for third star companions. Such tertiaries will periodically alter the eclipse timings through light travel time and dynamical effects.
Belyawsky +39 more
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SoftwareXLEO (Low Earth Orbit)-based PNT (Positioning, Navigation and Timing) has become a research topic of much interest and a focus of development. As LEO satellites for PNT are expected to independently provide space-time references in the future, similar to ...
Zhao Xi, Yu Baoguo, Luo Bin
doaj +1 more source
No variations in transit times for Qatar-1 b
, 2015 The transiting hot Jupiter planet Qatar-1 b was presented to exhibit variations in transit times that could be of perturbative nature. A hot Jupiter with a planetary companion on a nearby orbit would constitute an unprecedented planetary configuration ...
Aceituno, F. J. +13 more
core +1 more source
Near-Real-Time Global Thermospheric Density Variations Unveiled by Starlink Ephemeris
Remote SensingPrevious efforts to retrieve thermospheric density using satellite payloads have been limited to a small number of satellites equipped with GNSS (Global Navigation Satellite System) receivers and accelerometers.
Zhuoliang Ou +10 more
doaj +1 more source
The Navstar GPS master control station's Kalman filter experience [PDF]
The Navstar Global Positioning System (GPS) is a highly accurate space based navigation system providing all weather, 24 hour a day service to both military and civilian users.
Scardera, Michael P.
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Improving the Accuracy of the Martian Ephemeris Short-Term Prediction
Advances in Astronomy, 2018 The Chinese Mars exploration mission is planned to be launched in 2020, which includes an orbiter, a lander, and a rover. High precision Martian ephemeris is very important in Mars exploration, especially for the Martian orbit insertion and the Martian ...
Quan Shan +5 more
doaj +1 more source
How Well Do We Know the Orbits of the Outer Planets?
, 2009 This paper deals with the problem of astrometric determination of the orbital elements of the outer planets, in particular by assessing the ability of astrometric observations to detect perturbations of the sort expected from the Pioneer effect or other ...
Bevington +21 more
core +1 more source