Results 71 to 80 of about 134,911 (241)

Broadband Receiver for VLF On‐Orbit Wave‐Particle Interaction Experiments

Journal of Geophysical Research: Space Physics, Volume 130, Issue 3, March 2025.
Abstract A broadband, multi‐channel Very Low Frequency (VLF) radio receiver (BBR), developed as a sensitive analog, vector wave receiver for whistler‐mode signals in the VLF range, was successfully flown on the Air Force Demonstration Science Experiment (DSX) Mission to Mid‐Earth Orbit (Johnston et al., 2023, https://doi.org/10.1029/2022JA030771).
I. R. Linscott, U. S. Inan, D. S. Lauben, W. M. Farrell, J. Payne, B. Mossiwir, C. Wang, K. Lee, W. R. Johnston, M. J. Starks, J. P. McCollough, J. C. Sanchez, Y.‐J. Su   +12 more
wiley   +1 more source

Calibration and Impact of BeiDou Satellite-Dependent Timing Group Delay Bias

Remote Sensing, 2020
The accuracy of the timing group delay (TGD) transmitted in the broadcast ephemeris is an important factor that affects the service performance of a GNSS system.
Yize Zhang, Hu Wang, Junping Chen, Ahao Wang, Lingdong Meng, Ershen Wang   +5 more
doaj   +1 more source

Spatially Resolved Visible Wavelength Spectroscopy of the Galilean Moons With VLT/MUSE

Journal of Geophysical Research: Planets, Volume 130, Issue 3, March 2025.
Abstract We present observations of all four Galilean satellites using spatially resolved visible wavelength (475–935 nm) spectroscopic observations with the ground‐based VLT/MUSE + AOF facility in 2019. A range of features in the observed reflectance spectra were compared to laboratory measured spectra, and mapped to understand the spatial ...
Oliver R. T. King, Leigh N. Fletcher, Fraser Clarke, Andrea Hidalgo   +3 more
wiley   +1 more source

Reconstructing Equatorial Electron Flux Measurements From Low‐Earth‐Orbit: A Conjunction Based Framework

Space Weather, Volume 23, Issue 3, March 2025.
Abstract We present an artificial neural network model that reconstructs >30 keV electron flux measurements near the geomagnetic equator from low‐Earth‐orbit (LEO) observations, exploiting the global coherent nature of the high‐energy trapped electrons that constitute the radiation belts.
D. L. Stumbaugh, J. Bortnik, S. G. Claudepierre   +2 more
wiley   +1 more source

Radiation‐Belt Dropouts: Relationship With Geomagnetic Storms and MeV Precipitation

Geophysical Research Letters, Volume 52, Issue 4, 28 February 2025.
Abstract To better understand rapid radiation belt losses, this statistical study examines dropouts, defined as a phase‐space density (PSD) decrease by a factor of ≥5 ${\ge} 5$ within 8 hr. The relationship between dropouts, storm parameters, solar‐wind drivers, geomagnetic indices, and MeV electron precipitation is analyzed.
Domenique Freund, Lauren Blum, Jinbei Huang, Sergio Vidal‐Luengo, Alessandro Bruno, Ryuho Kataoka   +5 more
wiley   +1 more source

Astrometric positions for 18 irregular satellites of giant planets from 23 years of observations

, 2015
The irregular satellites of the giant planets are believed to have been captured during the evolution of the solar system. Knowing their physical parameters, such as size, density, and albedo is important for constraining where they came from and how ...
Andrei, A. H., Arlot, J. -E., Assafin, M., Benedetti-Rossi, G., Braga-Ribas, F., Camargo, J. I. B., Desmars, J., Dias-Oliveira, A., Duchemin, Y., Gomes-Júnior, A. R., Lainey, V., Morgado, B. E., Neto, D. N. da Silva, Thuillot, W., Vieira-Martins, R.   +14 more
core   +2 more sources

Stronger Evidence of a Subsurface Ocean Within Callisto From a Multifrequency Investigation of Its Induced Magnetic Field

AGU Advances, Volume 6, Issue 1, February 2025.
Abstract The magnetometer investigation of the Galileo mission used the phenomenon of magnetic induction to produce the most compelling evidence that subsurface oceans exist within our solar system. Although there is high certainty that the induced field measured at Europa is attributed to a global‐scale subsurface ocean, there is still uncertainty ...
Corey J. Cochrane, Steven D. Vance, Julie C. Castillo‐Rogez, Marshall J. Styczinski, Lucas Liuzzo   +4 more
wiley   +1 more source

A novel GNSS precise point positioning method based on spherical harmonic expansion

All Earth, 2023
The Global Navigation Satellite System (GNSS) precise point positioning (PPP) from carrier-phase data is influenced by complex elements. The error sources are divided into two categories according to their relation to the signal propagation path.
Yanchen Cao, Jinyun Guo, Hengyang Guo, Minghao Chang, Chunmei Zhao, Xin Liu   +5 more
doaj   +1 more source

Five New Transits of the Super-Neptune HD 149026 [PDF]

, 2007
We present new photometry of HD 149026 spanning five transits of its "super-Neptune" planet. In combination with previous data, we improve upon the determination of the planet-to-star radius ratio: R_p/R_star = 0.0491^{+0.0018}_{-0.0005}.
Broeg C., Claret A., Gregory W. Henry, Guillermo Torres, Halbwachs J. L., Joshua N. Winn, Matthew J. Holman, Perryman M. A. C.   +7 more
core   +3 more sources

Observing transiting exoplanets with the MicroObservatory: 43 new transit light curves of the hot Jupiter HAT-P-32b [PDF]

arXiv, 2020
Observations of 43 complete transits of the hot Jupiter exoplanet HAT-P-32b using the MicroObservatory 0.15-m robotic telescope network covering a period of 7 years are presented. Compared with the most recent ephemeris for the system, the precision of the mid-transit times yielded a root-mean-square value from the predicted model of 3.0 min.
arxiv