The Solar Sail Materials (SSM) project – Status of activities; ; et al in Advances in Space Research (2011), 48(11), 1922-1926 Detailed reference viewed: 20 (4 ULg) Influence of nuclear de-excitation on observables relevant for space explorationMancusi, Davide ; ; Cugnon, Joseph et alin Advances in Space Research (2011), 47(7), 1194-1199 Detailed reference viewed: 7 (1 ULg) Local ionospheric electron density profile reconstruction in real time from simultaneous ground-based GNSS and ionosonde measurements; ; et al in Advances in Space Research (2011), 47(7), 1172-1180 Detailed reference viewed: 35 (6 ULg) Ionosphere modelling for Galileo single frequency users: illustration of the combination of the NeQuick model and GNSS data ingestionBidaine, Benoît ; Warnant, René ![]() in Advances in Space Research (2011), 47(2), 312-322 The ionospheric effect remains one of the main factors limiting the accuracy of Global Navigation Satellite Systems (GNSS) including Galileo. For single frequency users, this contribution to the error ... [more ▼] The ionospheric effect remains one of the main factors limiting the accuracy of Global Navigation Satellite Systems (GNSS) including Galileo. For single frequency users, this contribution to the error budget will be mitigated by an algorithm based on the NeQuick global ionospheric model. This quick-run empirical model provides flexible solutions for combining ionospheric information obtained from various sources, from GNSS to ionosondes and topside sounders. Hence it constitutes an interesting simulation tool not only serving Galileo needs for mitigation of the ionospheric effect but also widening the use of new data. In this study, we perform slant TEC data ingestion - the optimisation procedure underlying the Galileo single frequency ionospheric correction algorithm - into NeQuick for a dozen locations around the world where both an ionosonde and a GPS receiver are installed. These co-located instruments allow us to compare measured and modelled vertical TEC showing for example global statistics or dependence towards latitude. We analyse measurements for the year 2002 (high solar activity level) giving an insight into the situation we could observe when Galileo reaches its Full Operation Capability, during the next solar maximum. At last we compare Galileo and GPS ionospheric corrections. For Galileo, we end up with an underestimation of 11% and 4% depending on the version of NeQuick embedded in the algorithm, as well as a 22% standard deviation. This means respectively twice, five and 1.5 times better than GPS. [less ▲] Detailed reference viewed: 166 (45 ULg) The extension of the INCL model for simulation of shielding in spacePedoux, Sophie ; Cugnon, Joseph ; Mancusi, Davide et alin Advances in Space Research (2011), 48(2), 383-389 Radiation hazard for space missions is mainly due to cosmic ray protons, helium nuclei and light ions, whose energy spectrum is maximum around 1 GeV per nucleon but remains non-negligible for energies up ... [more ▼] Radiation hazard for space missions is mainly due to cosmic ray protons, helium nuclei and light ions, whose energy spectrum is maximum around 1 GeV per nucleon but remains non-negligible for energies up to 15 GeV per nucleon. Nuclear reactions induced by high energy protons are often described by intranuclear cascade plus evaporation models. The attention is focused here on the Liège Intranuclear Cascade model (INCL), which has been shown to reproduce fairly well a great deal of experimental data for nucleon-induced reactions in the 200 MeV to 2 GeV range, when coupled with the ABLA evaporation-fission code. In order to extend the model to other conditions relevant for space radiation, three improvements of INCL are under development. They are reported on here. First, the reaction model has been extended to nucleon-nucleus reactions at incident energies up to 15 GeV, mainly by the inclusion of additional pion production channels in nucleon-nucleon collisions during the cascade. Second, a coalescence mechanism for the emission of light charged particles has been implemented recently. Finally, the model has been modified in order to accommodate light ions as projectiles. First results are shown and compared with illustrative experimental data. Implications for issues concerning radiation protection in space are discussed. [less ▲] Detailed reference viewed: 7 (2 ULg) Total Electron Content Monitoring using triple frequency GNSS: results with Giove-A/-B data; Warnant, René ![]() in Advances in Space Research (2011), 47 Detailed reference viewed: 47 (9 ULg) PHITS simulations of the Matroshka experiment; ; Mancusi, Davide et alin Advances in Space Research (2010), 40(10), 1266-1272 Detailed reference viewed: 4 (0 ULg) Assessment of the NeQuick model at mid-latitudes using GNSS TEC and ionosonde dataBidaine, Benoît ; in Advances in Space Research (2010), 45(9), 1122-1128 The modelling of the Total Electron Content (TEC) plays an important role in global navigation satellite systems (GNSS) accuracy, especially for single-frequency receivers, the most common ones ... [more ▼] The modelling of the Total Electron Content (TEC) plays an important role in global navigation satellite systems (GNSS) accuracy, especially for single-frequency receivers, the most common ones constituting the mass market. For the latter and in the framework of Galileo, the NeQuick model has been chosen for correcting the ionospheric error contribution and will be integrated into a global algorithm providing the users with daily updated information. In order to reach the ionosphere error correction level objective, the model itself as well as its use for Galileo are investigated. In our comparison process, we take advantage of various ionosphere data from several European stations (Dourbes in Belgium, El Arenosillo and Roquetes in Spain) where ionosonde and GPS TEC data are available for different solar activity levels. These data allow us to study NeQuick representation of the ionosphere at mid-latitudes. Constraining the model with ionosonde measurements, we investigate the difference between GPS-derived vertical TEC and corresponding values from NeQuick for a high solar activity level (year 2002). With this approach, we reach residual errors of less than 20% in standard deviation. We especially highlight the improvements from the latest (second) version of NeQuick and show the critical importance of the topside formulation. [less ▲] Detailed reference viewed: 107 (35 ULg) The distributions of the OH Meinel and O[SUB][/SUB](a[SUP]1[/SUP]Δ-X[SUP]3[/SUP]Σ) nightglow emissions in the Venus mesosphere based on VIRTIS observationsGérard, Jean-Claude ; Soret, Lauriane ; Saglam, Adem et alin Advances in Space Research (2010), 45 O[SUB][/SUB](a[SUP]1[/SUP]Δ) and recently discovered OH Meinel nightglow emissions have been observed at the limb with the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS-M) instrument on board ... [more ▼] O[SUB][/SUB](a[SUP]1[/SUP]Δ) and recently discovered OH Meinel nightglow emissions have been observed at the limb with the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS-M) instrument on board the Venus Express satellite. Hydroxyl bands belonging to Δv=1 sequence between 2.60and3.14μm and to Δv=2 sequence at 1.40-1.46μm have been unambiguously identified. In this study, we analyze the statistical distribution of the Δv=1 OH Meinel band sequence and the a[SUP]1[/SUP]Δ[SUB]g[/SUB]-X[SUP]3[/SUP]Σ (0-0) band of the O[SUB][/SUB] Infrared Atmospheric bands at 1.27 μm. We also present an analysis of the correlation between the two emissions. From a statistical point of view, we find that the limb intensity of both emissions reach their maximum value near the antisolar point, while they are significantly dimmer in the vicinity of the terminator. The average altitude of the limb emissions peaks are 95.3 ± 3 km and 96 ± 2.7 km, respectively for the OH Δv=1 sequence and O[SUB][/SUB](a[SUP]1[/SUP]Δ) emissions. The average intensities are 0.41 ± 0.37 MR and 28 ± 22 MR, respectively, corresponding to a mean ratio of about 70. The altitude of the OH nightglow layer is closely related to that of the O[SUB][/SUB](a[SUP]1[/SUP]Δ) emission and some level of co-variation of the maximum intensity along the line of sight is observed. It is suggested that the global subsolar to antisolar circulation plays a key in the control of both airglows by carrying oxygen atoms from the day to the night side of the planet. The O atoms recombine to produce O[SUB][/SUB](a[SUP]1[/SUP]Δ) molecules and they also act as precursors of ozone whose reaction with H produces excited hydroxyl. [less ▲] Detailed reference viewed: 32 (10 ULg) Seasonal variations of storm-time TEC at European middle latitudes; ; Warnant, René ![]() in Advances in Space Research (2010), 46(10), 1318-1325 Detailed reference viewed: 20 (3 ULg) Extension of INCL4 between 2 and 15 GeVPedoux, Sophie ; Cugnon, Joseph ; et alin Advances in Space Research (2009), 44(8), The intranuclear cascade model INCL4 has been shown to be very successful for describing, without adjustable parameters, a whole set of data for p-induced reactions in the 40 MeV–2 GeV energy range. In ... [more ▼] The intranuclear cascade model INCL4 has been shown to be very successful for describing, without adjustable parameters, a whole set of data for p-induced reactions in the 40 MeV–2 GeV energy range. In view of its possible application to cosmic ray interactions, the INCL4 code has been extended to the 2–15 GeV energy range, so covering a large part of the spectrum of the incident energy of the cosmic rays. In this paper, the changes brought into the INCL4 code are discussed and some illustrative comparisons between the results given by the modified version of the code and experimental data are presented. [less ▲] Detailed reference viewed: 7 (5 ULg) Trans-ionospheric GPS signal delay gradients observed over mid-latitude Europe during the geomagnetic storms of October-November 2003; Warnant, René ; in Advances in Space Research (2009), 43(9), 1314-1324 Detailed reference viewed: 13 (1 ULg) Ionospheric slab thickness - Analysis, modelling and monitoring; Warnant, René ![]() in Advances in Space Research (2009), 44(10), 1295-1303 Detailed reference viewed: 20 (1 ULg) Modeling medium-scale TEC structures observed by Belgian GPS receivers network; ; et al in Advances in Space Research (2009), 43 Detailed reference viewed: 25 (4 ULg) The INCL model for spallation reactions below 10 GeVPedoux, Sophie ; Cugnon, Joseph ; et alin Advances in Space Research (2007), 40(9), 1332-1338 The Liège intranuclear cascade (INCL) model is shortly presented. The predictive power of its standard version concerning the description of nucleon-induced spallation reactions in the 200 MeV to ~2 GeV ... [more ▼] The Liège intranuclear cascade (INCL) model is shortly presented. The predictive power of its standard version concerning the description of nucleon-induced spallation reactions in the 200 MeV to ~2 GeV range of incident energy is indicated. Current improvements of the model, in particular its extension to higher energies, are emphasized. The capabilities of the model for possible applications in astrophysics, space research and protontherapy are pointed out. [less ▲] Detailed reference viewed: 14 (1 ULg) Ionospheric and geomagnetic conditions during periods of degraded GPS position accuracy : 2. RTK events during disturbed and quiet geomagnetic conditionsWarnant, René ; ; et alin Advances in Space Research (2007), 39(5), 881-888 Detailed reference viewed: 25 (7 ULg) Ionospheric and geomagnetic conditions during periods of degraded GPS position accuracy : 1. Monitoring variability in TEC which degrades the accuracy of Real Time Kinematic GPS applicationsWarnant, René ; ; et alin Advances in Space Research (2007), 39(5), 875-880 Detailed reference viewed: 16 (5 ULg) Spectroscopic anatomy of a meteor with the very large telescope (ESO)Jehin, Emmanuel ; ; et alin Advances in Space Research (2007), 39 A meteor spectrum was recorded serendipitously with the ESO Very Large Telescope during a long exposure in long-slit spectroscopic mode with the instrument FORS1. The -8 magnitude fireball crossed the ... [more ▼] A meteor spectrum was recorded serendipitously with the ESO Very Large Telescope during a long exposure in long-slit spectroscopic mode with the instrument FORS1. The -8 magnitude fireball crossed the narrow (1 arcsec × 7 arcmin) slit during the observation of a high z supernova in normal service mode operation on May 12, 2002. The spectrum covers the range of 637 1050 nm, where the meteor’s air plasma emissions from N[SUB]2[/SUB], N and O dominate. The meteor trail appears moreover resolved along the slit but we conclude that this is because the meteor at 100 km altitude was out of focus for the VLT. The plasma excitation temperature varies only from about 4300 to 4365 K across the trail, based on the ratio of atomic and molecular nitrogen emissions. This is in agreement with the fact that the trail is not actually spatially resolved. Finally, carbon atom emission is not detected in the relatively unexplored range above 900 nm. [less ▲] Detailed reference viewed: 1 (0 ULg) DYNAMO: a Mars upper atmosphere package for investigating solar wind interaction and escape processes, and mapping Martian fields; ; et al in Advances in Space Research (2004), 33 DYNAMO is a small multi-instrument payload aimed at characterizing current atmospheric escape, which is still poorly constrained, and improving gravity and magnetic field representations, in order to ... [more ▼] DYNAMO is a small multi-instrument payload aimed at characterizing current atmospheric escape, which is still poorly constrained, and improving gravity and magnetic field representations, in order to better understand the magnetic, geologic and thermal history of Mars. The internal structure and evolution of Mars is thought to have influenced climate evolution. The collapse of the primitive magnetosphere early in Mars history could have enhanced atmospheric escape and favored transition to the present arid climate. These objectives are achieved by using a low periapsis orbit. DYNAMO has been proposed in response to the AO released in February 2002 for instruments to be flown as a complementary payload onboard the CNES Orbiter to Mars (MO-07), foreseen to be launched in 2007 in the framework of the French PREMIER Mars exploration program. MO-07 orbital phase 2b (with an elliptical orbit of periapsis 170 km), and in a lesser extent 2a, offers an unprecedented opportunity to investigate by in situ probing the chemical and dynamical properties of the deep ionosphere, thermosphere, and the interaction between the atmosphere and the solar wind, and therefore the present atmospheric escape rate. Ultraviolet remote sensing is an essential complement to characterize high, tenuous, layers of the atmosphere. One Martian year of operation, with about 5,000 low passes, should allow DYNAMO to map in great detail the residual magnetic field, together with the gravity field. Additional data on the internal structure will be obtained by mapping the electric conductivity, sinergistically with the NETLANDER magnetic data. Three options have been recommended by the International Science and Technical Review Board (ISTRB), who met on July 1st and 2nd, 2002. One of them is centered on DYNAMO. The final choice, which should be made before the end of 2002, will depend on available funding resources at CNES. [less ▲] Detailed reference viewed: 39 (2 ULg) XMM-Newton high-resolution X-ray spectroscopy of the Wolf-Rayet object WR25 (WN6ha+O4f); ; et al in Advances in Space Research (2003), 32(6), 1161-1165 We report the analysis of the X-ray spectrum of the Wolf-Rayet star WR 25, observed by RGS and EPIC-MOS on board XMM-Newton. Temperatures up to 40 MK have been determined. Strong absorption, exceeding the ... [more ▼] We report the analysis of the X-ray spectrum of the Wolf-Rayet star WR 25, observed by RGS and EPIC-MOS on board XMM-Newton. Temperatures up to 40 MK have been determined. Strong absorption, exceeding the value due to the Inter Stellar Medium (ISM) has been detected and assigned to the dense stellar wind. (C) 2003 COSPAR. Published by Elsevier Ltd. All rights reserved. [less ▲] Detailed reference viewed: 25 (4 ULg) |
||