Multifrequency algorithms for precise point positioning: MAP3     

B. Moreno Monge  G. Rodríguez-Caderot  M. C. de Lacy 《GPS Solutions》2014,18(3):355-364

We present the new MAP3 algorithms to perform static precise point positioning (PPP) from multifrequency and multisystem GNSS observations. MAP3 represents a two-step strategy in which the least squares theory is applied twice to estimate smoothed pseudo-distances, initial phase ambiguities, and slant ionospheric delay first, and the absolute receiver position and its clock offset in a second adjustment. Unlike the classic PPP technique, in our new approach, the ionospheric-free linear combination is not used. The combination of signals from different satellite systems is accomplished by taking into account the receiver inter-system bias. MAP3 has been implemented in MATLAB and integrated within a complete PPP software developed on site and named PCube. We test the MAP3 performance numerically and contrast it with other external PPP programs. In general, MAP3 positioning accuracy with low-noise GPS dual-frequency observations is about 2.5 cm in 2-h observation periods, 1 cm in 10 h, and 7 mm after 1 day. This means an improvement in the accuracy in short observation periods of at least 7 mm with respect to the other PPP programs. The MAP3 convergence time is also analyzed and some results obtained from real triple-frequency GPS and GIOVE observations are presented.  相似文献   

Topo-Iberia project: CGPS crustal velocity field in the Iberian Peninsula and Morocco     

J. Garate  J. Martin-Davila  G. Khazaradze  A. Echeverria  E. Asensio  A. J. Gil  M. C. de Lacy  J. A. Armenteros  A. M. Ruiz  J. Gallastegui  F. Alvarez-Lobato  C. Ayala  G. Rodríguez-Caderot  J. Galindo-Zaldívar  A. Rimi  M. Harnafi 《GPS Solutions》2015,19(2):287-295

  相似文献   

A consistent combination of GNSS and SLR with minimum constraints   总被引：1，自引：1，他引：0  

Susanne Glaser  Mathias Fritsche  Krzysztof Sośnica  Carlos Javier Rodríguez-Solano  Kan Wang  Rolf Dach  Urs Hugentobler  Markus Rothacher  Reinhard Dietrich 《Journal of Geodesy》2015,89(12):1165-1180

  相似文献   

New insights into geochemical behaviour in ancient marine carbonates (Upper Jurassic Ammonitico Rosso): Novel proxies for interpreting sea‐level dynamics and palaeoceanography          下载免费PDF全文

Rute Coimbra  Adrian Immenhauser  Federico Olóriz  Víctor Rodríguez‐Galiano  Mario Chica‐Olmo 《Sedimentology》2015,62(1):266-302

Elemental concentrations in Phanerozoic sea water are known to fluctuate both in time and space. With regard to carbonates precipitated from marine fluids, elemental concentrations in the carbonate crystal lattice are affected by a complex array of equilibrium and non‐equilibrium as well as post‐depositional alteration processes. To assess the potential of carbonate elemental chemostratigraphy, seven Upper Jurassic sections were investigated along a proximal to distal transect across the south‐east Iberian palaeomargin. The aim was to explore stratigraphic and spatial variations in calcium, strontium, magnesium, iron and manganese elemental abundances. The epicontinental geochemical record is influenced by the combination of continental runoff and a significant diagenetic overprint. In contrast, the epioceanic geochemical record agrees with reconstructed open marine sea water values, reflecting a moderate degree of syn‐depositional to early marine pore water diagenesis. Establishing a fair degree of preservation of matrix micrite, a thorough statistical approach was applied and elemental associations tested for their environmental significance. Principal component and hierarchical cluster analyses revealed a persistent relation between carbonate magnesium, iron and strontium abundances. Processes related to early diagenetic nodulation in Ammonitico Rosso facies most probably account for the incorporation of these elements in the calcium carbonate lattice. The clear decoupling of carbonate manganese abundance with respect to the remaining elements is documented and related to high sea floor spreading rates and hydrothermal activity during the Late Jurassic. The investigation of potential time‐fluctuation of geochemical patterns was approached through variogram computation. The observed temporal behaviour is most likely to be forced by relative sea‐level dynamics, reflecting Late Jurassic palaeoceanographic conditions and potential planetary interactions. The data obtained in this study highlight the utility of elemental data from carbonate matrix micrites as geochemical proxies for studying the influence of remote trigger factors.  相似文献   

Low Speed Granular–Granular Impact Crater Opening Mechanism in 2D Experiments     

Roberto Bartali  Yuri Nahmad-Molinari  Gustavo M. Rodríguez-Liñán 《Earth, Moon, and Planets》2015,116(2):115-138

  相似文献   

Climate change and infectious diseases: Can we meet the needs for better prediction?     

Xavier Rodó  Mercedes Pascual  Francisco J. Doblas-Reyes  Alexander Gershunov  Dáithí A. Stone  Filippo Giorgi  Peter J. Hudson  James Kinter  Miquel-Àngel Rodríguez-Arias  Nils Ch. Stenseth  David Alonso  Javier García-Serrano  Andrew P. Dobson 《Climatic change》2013,118(3-4):625-640

The next generation of climate-driven, disease prediction models will most likely require a mechanistically based, dynamical framework that parameterizes key processes at a variety of locations. Over the next two decades, consensus climate predictions make it possible to produce forecasts for a number of important infectious diseases that are largely independent of the uncertainty of longer-term emissions scenarios. In particular, the role of climate in the modulation of seasonal disease transmission needs to be unravelled from the complex dynamics resulting from the interaction of transmission with herd immunity and intervention measures that depend upon previous burdens of infection. Progress is also needed to solve the mismatch between climate projections and disease projections at the scale of public health interventions. In the time horizon of seasons to years, early warning systems should benefit from current developments on multi-model ensemble climate prediction systems, particularly in areas where high skill levels of climate models coincide with regions where large epidemics take place. A better understanding of the role of climate extremes on infectious diseases is urgently needed.  相似文献   

Multifractal analysis of the rainfall time distribution on the metropolitan area of Barcelona (Spain)     

R. Rodríguez  M. C. Casas  A. Redaño 《Meteorology and Atmospheric Physics》2013,121(3-4):181-187

In most of the studies on scale properties in the rainfall process, multifractal behavior has been investigated without taking into account the different rain generation mechanisms involved. However, it is known that rain processes are related to certain scales, determined by climatological characteristics as well as regional and local meteorological features. One of the implications derived from these correspondences is the possibility that the multifractal parameters of the rainfall could depend on the dominant precipitation generation mechanism. Fractal analysis techniques have been applied in this work to rainfall data recorded in the metropolitan area of Barcelona in the period 1994–2001, as well as to a selection of synoptic rainfall events registered in the same city in the period 1927–1992. The multifractal parameters obtained have been significantly different in each case probably showing the influence of the rain generation mechanisms involved. This influence has been revealed also in the analysis of the effects of seasonality on the multifractal behavior of rainfall in Barcelona.  相似文献   

The ionized gas in the Galactic Center Radio Arc     

N.J. RodrÍguez-Fernández  J. MartÍn-Pintado  P. de Vicente 《Astrophysics and Space Science》2002,281(1-2):333-334

  相似文献   

The shell spectrum of CH Cygni in 1981     

M. H. Rodríguez 《Astrophysics and Space Science》1984,102(1):123-129

The shell spectrum of CH Cyg observed in 1981 has been analyzed by the curve of growth method and using the equivalent widths of Balmer lines. The following parameters for the region of the shell where the absorption spectrum is formed have been obtained: excitation temperatureT _ex=9000 K, microturbulent velocityv _t =16 km s^–1, electron densityn _e=6.3×10¹², number of active hydrogen atoms in the second excited stateN _0.2=5.8×10¹⁵, and the effective height of the absorption spectrum formation regionH=10⁵ km.  相似文献   

Neoproterozoic–Cambrian synsedimentary magmatism in the Central Iberian Zone (Spain): geology,petrology and geodynamic significance     

M.?D.?Rodríguez-AlonsoEmail author  M.?Peinado  M.?López-Plaza  P.?Franco  A.?Carnicero  J.?C.?Gonzalo 《International Journal of Earth Sciences》2004,93(5):897-920

Petrographic, geochemical and field studies in low grade metamorphic areas (Ciudad Rodrigo-Hurdes-Sierra de Gata domain, CRHSG, central-western Spain) show that Neoproterozoic-Lowermost Cambrian series in the Central Iberian Zone (CIZ) record two kinds of provenance sources including: (1) detrital material derived from recycled orogens and (2) a Cadomian coeval juvenile contribution that governs their isotopic signature. Evidence of magmatism contemporaneous with Neoproterozoic-Cambrian sedimentation is provided by the presence of coherent, massive volcanic rocks (metabasalts, metaandesites, and metarhyolites), volcaniclastic shales, sandstones, conglomerates and breccias. The appearance of volcanogenic lithic fragments and crystals mixed in different proportions with siliciclastic constituents and also present within calcareous components in the sedimentary succession, reinforces this evidence. Although most of the selected volcanic and volcaniclastic samples appear to show tholeiitic affinity, some of them display calc-alkaline affinity. Different trace element ratios, such as Sm/Nd, Nb/Yb and Ta/Yb, suggest a magmatic evolution in the same tectonic setting. The geochemical results reported here support the existence of an active geodynamic setting as a direct contributor to the synsedimentary and magmatic content of the Neoproterozoic–Lowermost Cambrian successions in the CIZ. In particular, the relatively high Nd _(T) values and the high range of f ^Sm/Nd ratios are consistent with an active margin during the Neoproterozoic–Early Cambrian. The existence of tectonic activity is also confirmed by the presence of synsedimentary deformation and volcanic rocks. All of these traits favour a geodynamic model in which the Iberian Cadomian segment represented in the CIZ would have been part of an active northern margin of Gondwana, with an associated magmatic arc and related basins during Neoproterozoic–Lower Cambrian times. A proposed link between the Ossa Morena and the Central Iberian Zones might account for late Cadomian pull-apart basins developed on both sides of the magmatic arc, sharing the same scenario and involving similar magmatic activity during the Neoproterozoic–Cambrian transition.

M. D. Rodríguez-AlonsoEmail: Phone: +34-923-294498Fax: +34-923-294514

  相似文献