Effects of building materials on UHF ranging signals     

Richard?KlukasEmail author  Olivier?Julien  Lei?Dong  Elizabeth?Cannon  Gerard?Lachapelle 《GPS Solutions》2004,8(1):1-8

Positioning and tracking inside buildings using wireless location methods has recently received considerable attention. One method is the estimation of the time of arrival of satellite or terrestrial-based radio frequency signals in order to produce ranges from the transmitter to the receiver. This paper investigates the effect of walls made of various construction materials on the penetration of ranging signals. In the tests conducted, a GPS pseudo-satellite transmits a pseudorandom noise code at a carrier frequency of 1.57542 GHz. After penetrating walls made of plywood, gyprock and cinder blocks, the signal is received by a GPS receiver which measures the carrier phase and the pseudorange between the transmitter and receiver using code correlation. Compared to measurements obtained with no walls present, the effect on the measurements is determined. The results indicate that the carrier phase measurement is superior to the pseudorange in terms of noise, stability, and the magnitude of the effect of the walls on the range obtained. Ranges based on the carrier phase only change by a few centimeters. Given that the integer number of cycles of the phase can be determined and phase lock is maintained, the carrier phase measurement shows considerable promise for indoor ranging.  相似文献   

Author Index     

Olivier Fouché  Jean Diebolt 《Mathematical Geology》2004,36(8):993-994

Authors Index

Author Index  相似文献   

Recent temporal change in the stress state and modern stress field along the North Anatolian Fault Zone (Turkey)     

Olivier Bellier  Semir Över  ré Poisson  Jean Andrieux 《Geophysical Journal International》1997,131(1):61-86

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Minor changes in surface-water fertility across the oceanic anoxic event 1d (latest Albian,SE France) evidenced by calcareous nannofossils     

Fabienne?GiraudEmail author  Davide?Olivero  Fran?ois?Baudin  Stéphane?Reboulet  Bernard?Pittet  Olivier?Proux 《International Journal of Earth Sciences》2003,92(2):267-284

The latest Albian sediments deposited in the Vocontian basin in south-eastern France record the oceanic anoxic event (OAE) 1d, locally named the Breistroffer interval. They are represented by argillaceous marls and marls, containing organic matter (total organic carbon varying from 0.8 to 1%). Changes in calcareous nannofossil abundance and assemblage composition as well as macrofauna abundance, ichnofossil assemblage, and bioturbation intensity were analysed in order to evaluate the main palaeoenvironmental factors controlling the deposition of the OAE 1d sediments in this area. The pelagic carbonate production is limited and the carbonate fraction is predominantly of nektonic/benthic, and of allochthonous origin from carbonate platforms. The enrichment in organic carbon within the Breistroffer interval is weak and not associated with high surface-water productivity. The organic matter is mainly terrigenous. Its record is due to (1) a good preservation under dysoxic conditions within the sediments, and (2) a weak input of allochthonous carbonates. Eustatic fluctuations strongly influenced the variations of nannofossil and macrofauna abundances. Distinctive patterns in nannofossil assemblages and macrofauna abundances within the Breistroffer interval are also recognized, reflecting changes from mesotrophic to more oligotrophic conditions which are probably controlled by climate.  相似文献   

On the composition of ices incorporated in Ceres     

Olivier Mousis  Yann Alibert 《Monthly notices of the Royal Astronomical Society》2005,358(1):188-192

We use the clathrate hydrate trapping theory and gas drag formalism to calculate the composition of ices incorporated in the interior of Ceres. Utilizing a time-dependent solar nebula model, we show that icy solids can drift from beyond 5 au to the present location of the asteroid and be preserved from vaporization. We argue that volatiles were trapped in the outer solar nebula in the form of clathrate hydrates, hydrates and pure condensates prior to having been incorporated in icy solids and subsequently in Ceres. Under the assumption that most of volatiles were not vaporized during the accretion phase and the thermal evolution of Ceres, we determine the per mass abundances with respect to H₂O of CO₂, CO, CH₄, N₂, NH₃, Ar, Xe and Kr in the interior of the asteroid. The Dawn space mission, scheduled to explore Ceres in August 2014, may have the capacity to test some predictions. We also show that an in situ measurement of the D/H ratio in H₂O in Ceres could constrain the distance range in the solar nebula where its icy planetesimals were produced.  相似文献   

Landslide risk management in Switzerland   总被引：1，自引：2，他引：1  

Olivier Lateltin  Christoph Haemmig  Hugo Raetzo  Christophe Bonnard 《Landslides》2005,2(4):313-320

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Hydromechanical behaviour of a compacted swelling soil over a wide suction range     

Olivier Cuisinier 《Engineering Geology》2005,81(3):204-212

A study of the hydromechanical behaviour of a compacted swelling material in the range of suctions comprised between 0 and 40 MPa was performed. This study has required the development of two kinds of suction controlled oedometer devices based on two different suction control techniques. In the range of suctions higher than 8.5 MPa, the saturated salt solutions method was used and a new oedometer using this suction control technique was developed. For suctions lower than 8.5 MPa an osmotic oedometer was used. Despite the differences between the applied suction components (matric and total), the correlation between the two methods was verified for the tested material. The second part of the paper presents a set of oedometer tests conducted under various suctions. The effect of the applied suction on the hydromechanical parameters was studied. First, two swelling phases were highlighted: a low swelling phase above a suction of 4 MPa and a high swelling one below this value. These phases were considered as being related to the microstructure of compacted swelling clays. Secondly, it was shown that the slopes of the elastic part and of the plastic part of the consolidation curves were not influenced significantly by the applied suctions. In opposition, the preconsolidation pressure is affected by the decrease of the applied suctions even in the low swelling phase. Such a behaviour could be explained by the effects of wetting on the microstructure.  相似文献   

Geophysical excitation of the Earth orientation parameters EOP and its contribution to GGOS     

Vronique Dehant  Olivier de Viron  Jean-Pierre Barriot 《Journal of Geodynamics》2005,40(4-5):394

We discuss how the geophysical fluids affect the Earth orientation parameters (EOP) and in particular polar motion and nutation. We show that the Earth orientation modeling is a perfect example of the integrated approach recommended by GGOS. GGOS considers the Earth system as a whole, including the solid Earth as well as the fluid components; geodesy observes and models the dynamics inside this system through the static and time-varying gravity field, the station displacements, and the Earth orientation parameters and the associated length-of-day variation, nutation and polar motion. Global-scale transfer in the Earth system and its geodetic consequences is proposed to be the central theme of GGOS. We show that the Earth orientation parameters perfectly fit this theme.  相似文献   

Morphology and sedimentology of a complex debris flow in a clay‐shale basin     

Alexandre Remaître  Jean-Philippe Malet  Olivier Maquaire 《地球表面变化过程与地形》2005,30(3):339-348

Coupling morphological, sedimentological, and rheological studies to numerical simulations is of primary interest in defining debris‐flow hazard on alluvial fans. In particular, numerical runout models must be carefully calibrated by morphological observations. This is particularly true in clay‐shale basins where hillslopes can provide a large quantity of poorly sorted solid materials to the torrent, and thus change both the mechanics of the debris flow and its runout distance. In this context, a study has been completed on the Faucon stream (southeastern French Alps), with the objectives of (1) defining morphological and sedimentological characteristics of torrential watersheds located in clay‐shales, and (2) evaluating through a case study the scouring potential of debris flows affecting a clay‐shale basin. Morphological surveys, grain‐size distributions and petrographic analyses of the debris‐flow deposits demonstrate the granular character of the flow during the first hectometre, and its muddy character from there to its terminus on the debris fan. These observations and laboratory tests suggest that the contributing areas along the channel have supplied the bulk of the flow material. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

Molybdenite Re–Os dating constrains gravitational collapse of the Sveconorwegian orogen, SW Scandinavia     

Bernard Bingen  Holly J. Stein  Michel Bogaerts  Olivier Bolle  Joakim Mansfeld 《Lithos》2006,87(3-4):328-346

Re–Os dating of molybdenite from small deposits is used to define crustal domains exhibiting ductile versus brittle behaviour during gravitational collapse of the Sveconorwegian orogen in SW Scandinavia. A 1019 ± 3 Ma planar quartz vein defines a minimum age for brittle behaviour in central Telemark. In Rogaland–Vest Agder, molybdenite associated with deformed quartz and pegmatite veins formed between 982 ± 3 and 947 ± 3 Ma in the amphibolite-facies domain (three deposits) and between 953 ± 3 and 931 ± 3 Ma west of the clinopyroxene-in isograd (two deposits) in the vicinity of the 0.93–0.92 Ga Rogaland anorthosite complex. The data constrain the last increment of ductile deformation to be younger than 0.95 and 0.93 Ga in these two metamorphic zones, respectively. Molybdenite is the product of an equilibrium between biotite, oxide and sulfide minerals and a fluid or hydrated melt phase, after the peak of 1.03–0.97 Ga regional metamorphism. Molybdenite precipitation is locally episodic. A model for gravitational collapse of the Sveconorwegian orogen controlled by lithospheric extension after 0.97 Ga is proposed. In the west of the orogen, the Rogaland–Vest Agder sector is interpreted as a large shallow gneiss dome, formed slowly in two stages in a warm and structurally weak crust. The first stage at 0.96–0.93 Ga was associated with intrusion of the post-collisional hornblende–biotite granite suite. The second stage at 0.93–0.92 Ga, restricted to the southwesternmost area, was associated with intrusion of the anorthosite–mangerite–charnockite suite. Most of the central part of the orogen was already situated in the brittle upper crust well before 0.97 Ga, and did not undergo significant exhumation during collapse. In the east of the orogen, situated against the colder cratonic foreland, exhumation of high-grade rocks of the Eastern Segment occurred between 0.97 and 0.95 Ga, and included preservation of high-pressure rocks but no plutonism.  相似文献