Search Publications
Attenuation of radio signals by the ionosphere of Mars: Theoretical development and application to MARSIS observations
Withers, Paul
We investigate the ionospheric conditions required to explain Mars Express Mars Advanced Radar for Subsurface and Ionosphere Sounding topside radar sounder observations of ionospheric attenuation in excess of 13 dB at 5 MHz during solar energetic particle events. We develop theoretical expressions for the attenuation caused by a layer of ionospher…
Using complex independent component analysis to extract weak returns in MARSIS radar data and their possible relation to a subsurface reflector on Mars
Nielsen, Erling; Zhang, Zhenfei
Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) radar signals returned from the surface and subsurface of the northern lowlands of Mars are mostly characterized as a prominent surface pulse followed by a tail of weak signals. We applied the method of blind source separation (BSS) using complex independent component analysis (CI…
Measurements of stray antenna capacitance in the STEREO/WAVES instrument: Comparison of the measured voltage spectrum with an antenna electron shot noise model
Eastwood, J. P.; Maksimovic, M.; Bale, S. D. +6 more
One of the most accurate techniques for in situ measuring the electron density and temperature in space plasmas is the quasi-thermal noise spectroscopy, which uses the voltage fluctuation spectrum on an electric antenna. This technique has been used successfully on the WIND and ULYSSES spacecraft; however, on STEREO this technique may only work in…
Correction to “Influence of an extended source on goniopolarimetry (or direction finding) with Cassini and Solar Terrestrial Relations Observatory radio receivers”
Cecconi, B.
Abstract Available from http://www.agu.org
A brief review of “solar flare effects” on the ionosphere
Lakhina, G. S.; Tsurutani, B. T.; Verkhoglyadova, O. P. +3 more
The study of solar flare effects (SFEs) on the ionosphere is having a renaissance. The development of GPS ground and satellite data for scientific use has opened up new means for high time resolution research on SFEs. At present, without continuous flare photon spectra (X rays, EUV, UV, and visible) monitoring instrumentation, the best way to mode…
Solar corona-induced fluctuations on spacecraft signal amplitude observed during solar superior conjunctions of the Cassini spacecraft
Morabito, David D.
During the superior solar conjunctions of interplanetary spacecraft, the emitted radio signals undergo increased amplitude scintillation, phase scintillation, and spectral broadening due to the intervening charged particles of the solar corona. The magnitude of these parameters generally increases as the angle between the spacecraft and the center…
A finite difference time domain model for the Titan ionosphere Schumann resonances
Navarro, E. A.; Soriano, A.; Morente, J. A. +1 more
This paper presents a numerical approach to model the electrical properties of Titan's atmosphere. The finite difference time domain technique is applied to model the atmosphere of Saturn's satellite in order to determine Schumann resonant frequencies and electromagnetic field distributions at the extremely low frequency range. Spherical coordinat…
Three-dimensional finite difference time domain modeling of the Schumann resonance parameters on Titan, Venus, and Mars
Yang, Heng; Pasko, Victor P.; Yair, Yoav
The conducting ionosphere and conducting surface of Titan, Venus, and Mars form a concentric resonator, which would support the possibility of the existence of global electromagnetic resonances. On Earth, such resonances are commonly referred to as Schumann resonances and are excited by lightning discharges. The detection of such resonances on oth…
Extreme solar EUV flares and ICMEs and resultant extreme ionospheric effects: Comparison of the Halloween 2003 and the Bastille Day events
Tsurutani, B. T.; Verkhoglyadova, O. P.; Judge, D. L. +9 more
Extreme solar flares can cause extreme ionospheric effects. The 28 October 2003 flare caused a ~25 total electron content units (TECU = 1016 el/m2 column density), or a ~30%, increase in the local noon equatorial ionospheric column density. The rise in the TEC enhancement occurred in ~5 min. This TEC increase was ~5 times the…
Modeling of Cluster's electric antennas in space: Application to plasma diagnostics
Sundkvist, D.; Pickett, J.; Lefebvre, B. +2 more
The main characteristics of the long-boom electric antennas installed on board the Cluster satellites are derived from finite element modeling in a kinetic and isotropic space plasma, in the frequency range of about 1-100 kHz. The model is based on the surface charge distribution method in quasi-static conditions. The impedances of both types of a…