Deep and Shallow Solid-Earth Structures Reconstructed with Sequential Integrated Inversion (SII) of Seismic and Gravity Data

In this paper, the possibility of using simultaneously seismic and gravity data, for the reconstruction of solid-Earth structures, has been investigated through the use of an algorithm which allows joint efficient and reliable optimisation of compressional velocity and mass density parameters. We view the measured data as a realisation of a stochastic process generated by the physical parameters to be sought and we construct a “probability density function” which includes three kinds of information: information derived from gravity measurements; information derived from seismic travel time inversion and information on the physical correlation among density and velocity parameters. We show that combining data has a beneficial effect on the inversion since: it makes the problem more stable and as a consequence, providing that the quality of data is sufficiently high, enables more accurate and reliable reconstruction of the unknown parameters. In this context, we look forward the GOCE mission, which promises high spatial resolution (100–200 km) and accurate (1–2 mGals) gravity data. We show results obtained from data sets calculated for a lateral inhomogeneous earth synthetic model and from seismic and gravity field data analysed: — in the framework of TOMOVES (TOMOgraphy of Mt. VESuvius) experiment, an European project aiming at reconstructing the 3-D image of Mt. Vesuvius volcano and the crust underneath. using high resolution seismic tomography techniques and other geophysical methods; — for a profile inserted in a project aiming at reconstructing the crustal structure between Corsica and the Northern Appennines which crosses the Ligurian Sea and cuts the Ligurian Appennines W of La Spezia, extending up to Parma. This revised version was published online in August 2006 with corrections to the Cover Date.     

X-38 integrated aero- and aerothermodynamic activities

The characterisation of the aeroshape selected for the X-38 [Crew Return Vehicle (CRV) demonstrator] is presently being performed as a co-operative endeavour between NASA, DLR (through its TETRA Program), and the European Space Agency (ESA) with Dassault Aviation integrating the aerodynamic and aerothermodynamic activities. The methodologies selected for characterizing the aerodynamic and aerothermodynamic environment of the X-38 are presented.     

JIRAM, the image spectrometer in the near infrared on board the Juno mission to Jupiter

The Jovian InfraRed Auroral Mapper (JIRAM) has been accepted by NASA for inclusion in the New Frontiers mission "Juno," which will launch in August 2011. JIRAM will explore the dynamics and the chemistry of Jupiter's auroral regions by high-contrast imaging and spectroscopy. It will also analyze jovian hot spots to determine their vertical structure and infer possible mechanisms for their formation. JIRAM will sound the jovian meteorological layer to map moist convection and determine water abundance and other constituents at depths that correspond to several bars pressure. JIRAM is equipped with a single telescope that accommodates both an infrared camera and a spectrometer to facilitate a large observational flexibility in obtaining simultaneous images in the L and M bands with the spectral radiance over the central zone of the images. Moreover, JIRAM will be able to perform spectral imaging of the planet in the 2.0-5.0 microm interval of wavelengths with a spectral resolution better than 10 nm. Instrument design, modes, and observation strategy will be optimized for operations onboard a spinning satellite in polar orbit around Jupiter. The JIRAM heritage comes from Italian-made, visual-infrared imaging spectrometers dedicated to planetary exploration, such as VIMS-V on Cassini, VIRTIS on Rosetta and Venus Express, and VIR-MS on the Dawn mission.     

Radar Signal Propagation and Detection Through Ice

In this paper we describe the existing and planned radar measurements of the planetary bodies. The dielectric properties of water ice and other potential surface and subsurface materials are discussed, as well as their dependency on temperature and structure. We then evaluate the performance of subsurface sounding radars using these parameters. Finally we describe some laboratory technique to help interpret the radar data, presenting some results obtained using dielectric spectroscopy methods.     

On the Origin of the Strong Intermittent Nature of Interplanetary Magnetic Field

We briefly discuss the strong intermittent nature of the interplanetary magnetic field, observing that similarity between its statistical properties and the passive scalar ones exists, and may arise from different dynamical mechanisms.     

线切割放电加工助航空客户飞得更高

过去20年里线切割的切割速度几乎增加了5倍,粗加工的直线切割速度可达600mm2/min;对大多数复杂型腔的加工速度较慢,但也可达到约350mm2/min。通过优化粗加工和精加工的策略,变质层几乎为零,同时没有材料或微观结构的变化,放电脉冲的控制特别是脉冲的持续时间和频率是达到最小损伤的关键因素。     

A mars communication constellation for human exploration and network science

This paper analyses the possibility of exploiting a small spacecrafts constellation around Mars to ensure a complete and continuous coverage of the planet, for the purpose of supporting future human and robotic operations and taking advantage of optical transmission techniques. The study foresees such a communications mission to be implemented at least after 2020 and a high data-rate requirement is imposed for the return of huge scientific data from massive robotic exploration or to allow video transmissions from a possible human outpost.     

Effects of X2-class solar flare events on ionospheric GPS-TEC and radio waves over Brazilian sector

In this investigation, we present and discuss the effects of 6 X2-class solar flare events in the ionospheric F region over Brazilian sector that occurred during 2013 to 2015. For this investigation, we present the vertical total electron content (VTEC) observations from nearly 120 Global Positioning System (GPS) receivers all over the Brazilian sector for each event. Also, ionospheric sounding observations obtained in São José dos Campos (23.2°S, 45.9°W, dip latitude 17.6°S; hereafter referred to as SJC), under the southern crest of the equatorial ionospheric anomaly (EIA), Brazil, are presented. The observations show that the greatest TEC impact occurs with the EUV fluxes increases lasting for more than one hour and when the solar active region is located close to the solar disc center. We present a detailed study of the efficiency of the EUV flux with wavelengths ranging from 0.1 to 190?nm for the F region ionization. The largest increase of ΔTEC occurs below the magnetic equator line, covering mainly the central, northeast, southeast and south regions, which includes the equatorial ionospheric anomaly (EIA) region. The ionograms show partial or total fade out in the echoes traces observed causing blackouts of radio signals of up to 60?min, which can have serious consequences to technological systems of public and private agencies around Brazilian sector. This study can help to better understand the effects of solar flares in the ionospheric F region.     

Orbital barium CRRES injection — Effective source of ionospheric wavelike disturbances

Spectral analysis of artificial wavelike disturbances (WD) in ionospheric parameters is presented. The sources of WD are barium clouds injections in CRRES perigee experiments. Plasma concentration pulsations are found in the ionospheric F2 layer maximum over Havana (Cuba) at distances 1500–2500 km from the barium injection. It was found that for the spectral component with 10 min period, the delay (relative to injection moment) corresponded to WD propagation velocity in 323–390 m/s band and depended on the specific injection conditions. It was shown that in every experiment the WD effective propagation velocity in the terminator region correlated with the sunlit part of the trajectory from the injection point to Havana. When comparing this WD type with WD's of other origins (from earthquakes, high-altitude explosions and solar terminator), it was shown that purposeful injection in the ionosphere of even a small barium quantity with orbital velocity in terminator region might be the effective means for generation or amplification of natural WD.