Crustal structure of central Tibet as derived from project INDEPTH wide-angle seismic data   总被引：6，自引：0，他引：6  

W. Zhao  J. Mechie  L. D. Brown  J. Guo  S. Haines  T. Hearn  S. L. Klemperer  Y. S. Ma  R. Meissner  K. D. Nelson  J. F. Ni   P. Pananont  R. Rapine  A. Ross  J. Saul 《Geophysical Journal International》2001,145(2):486-498

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Comportement de l'oscillateur DORIS/Jason au passage de l'anomalie sud-atlantique     

Pascal Willis  Bruce Haines  Jean-Paul Berthias  Pierre Sengenes  Jean-Louis Le Mouël 《Comptes Rendus Geoscience》2004,336(9):839-846

We point out an acceleration of the DORIS clock on-board the Jason satellite during passes over the South Atlantic Anomaly (SAA). When this effect is ignored in the current geodetic positioning of the DORIS stations, derived coordinates show almost linear trends in time, corresponding to anomalous horizontal and vertical velocities of the order of 1 m yr^?1. We propose a simple scientific explanation of this physical phenomenon that is corroborated by direct Jason/TOPEX clock comparisons with respect to the DORIS master beacons in Kourou and Toulouse. To cite this article: P. Willis et al., C. R. Geoscience 336 (2004).  相似文献   

Distributed deformation in the subducting lithosphere at Tonga     

Sarah Nothard  John Haines  James Jackson  Bill Holt 《Geophysical Journal International》1996,127(2):328-338

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Jason-1 Geophysical Performance Evaluation     

P. Vincent  S. D. Desai  J. Dorandeu  M. Ablain  B. Soussi  P. S. Callahan  B. J. Haines 《Marine Geodesy》2003,26(3):167-186

The Jason-1 satellite was launched on 7 December 2001 with the primary objective of continuing the high accuracy time series of altimeter measurements that began with the TOPEX/Poseidon mission in 1992. To achieve this goal, it is necessary to validate the performance of the Jason-1 measurement system, and to verify that its error budget is at least at the same level as that of the TOPEX/Poseidon mission. The article reviews the main components of the Jason-1 altimetric error budget from instrument characterization to the geophysical use of the data. Using the Interim Geophysical Data Records (16DR) that were distributed to the Jason-1 Science Working Team during the verification phase of the mission, it is shown that the Jason-1 mission is performing well enough to continue studies of the large-scale features of the ocean, and especially to continue time series of mean sea-level variations with an accuracy comparable to TOPEX/Poseidon.  相似文献   

One-Centimeter Orbit Determination for Jason-1: New GPS-Based Strategies   总被引：2，自引：0，他引：2  

Bruce Haines  Yoaz Bar-Sever  Willy Bertiger  Shailen Desai  Pascal Willis 《Marine Geodesy》2004,27(1):299-318

The U.S./French Jason-1 satellite is carrying a state-of-the-art GPS receiver to support precise orbit determination (POD) requirements. The performance of the Jason-1 “BlackJack” GPS receiver was strongly reflected in early POD results from the mission, enabling radial accuracies of 1-2 cm soon after the satellite's 2001 launch. We have made further advances in the GPS-based POD for Jason-1, most notably in describing the phase center variations of the on-board GPS antenna. We have also adopted new geopotential models from the Gravity Recovery and Climate Experiment (GRACE). The new strategies have enabled us to better exploit the unique contributions of the BlackJack GPS tracking data in the POD process. Results of both internal and external (e.g., laser ranging) comparisons indicate that orbit accuracies of 1 cm (radial RMS) are being achieved for Jason-1 using GPS data alone.  相似文献   

The Jason-1 Mission   总被引：1，自引：2，他引：1  

Yves M  nard  Lee-Lueng Fu  P. Escudier  F. Parisot  J. Perbos  P. Vincent  S. Desai  B. Haines  G. Kunstmann 《Marine Geodesy》2003,26(3):131-146

On December 7, 2001, the Jason-1 satellite was successfully launched by a Boeing Delta II rocket from the Vandenberg site in California, USA. Its main mission was to maintain the high accuracy altimeter measurements, provided since 1992 by TOPEX/Poseidon (T/P), ensuring continuity in observing and monitoring the ocean for intraseasonal to interannual changes, mean sea level, tides, and so forth. Despite four times less mass and power, the Jason-1 system has been designed to have the same performances as T/P, measuring sea surface topography at the centimeter level. This new Centre National d'Etudes Spatiales/National Aeronautics and Space Administration (CNES/NASA) mission also provides near real-time data for sea state and ocean forecast. The first 10 months of the Jason mission were dedicated to the verification of the system performance and cross-calibration with T/P measurements. A complete CALVAL plan was conducted by the Science and Project Teams of the mission based on in situ and regional experiments, global statistical approaches, and multisatellite comparisons, taking advantage of the T/P-Jason overlap during the first months of the mission. CALVAL and first science results showed that the Jason-1 performances were compliant with prelaunch specifications. This was a needed preamble before starting the routine phase of the mission in July 2003 with generation and distribution of validated geophysical data records to the whole user community.  相似文献   

GPU accelerated radio astronomy signal convolution     

Chris Harris  Karen Haines  Lister Staveley-Smith 《Experimental Astronomy》2008,22(1-2):129-141

The increasing array size of radio astronomy interferometers is causing the associated computation to scale quadratically with the number of array signals. Consequently, efficient usage of alternate processing architectures should be explored in order to meet this computational challenge. Affordable parallel processors have been made available to the general scientific community in the form of the commodity graphics card. This work investigates the use of the Graphics Processing Unit in the parallelisation of the combined conjugate multiply and accumulation stage of a correlator for a radio astronomy array. Using NVIDIA’s Compute Unified Device Architecture, our testing shows processing speeds from one to two orders of magnitude faster than a Central Processing Unit approach.  相似文献   

Exercising coastal state jurisdiction: The use of the military in Britain's maritime domain     

Steven Haines 《GeoJournal》1995,37(2):247-255

This paper discusses the ways in which the United Kingdom (UK) employs its armed forces (principally the Royal Navy) in support of civil authorities in tasks associated with maritime domain management. It briefly summarises the UK's response to developments in the law of the sea, explains that domestic jurisdiction has been extended to seawards and how this has meant a similar extension of civil administration. It follows this with an explanation of the doctrine by which the military are used in the UK in support of civil authorities and then summarises those maritime tasks currently undertaken by the military, including fishery protection, assistance to Customs and Excise, search and rescue and hydrographic surveying, amongst others.Any opinions expressed in this paper are the responsibility of the author alone. They are not to be interpreted as representing the official position of the Royal Navy, the Ministry of Defence or any other Department of Her Majesty's Government.  相似文献   

The galaxy environment of a quasar at z= 1.226: a possible cluster merger     

C. P. Haines  †  R. G. Clowes  L. E. Campusano  A. J. Adamson 《Monthly notices of the Royal Astronomical Society》2001,323(3):688-698

We have conducted ultra-deep optical and deep near-infrared observations of a field around the z =1.226 radio-quiet quasar 104420.8+055739 from the Clowes–Campusano LQG of 18 quasars at z ∼1.3, in search of associated galaxy clustering. Galaxies at these redshifts are distinguished by their extremely red colours, with I − K >3.75, and we find a factor ∼11 overdensity of such galaxies in a 2.25×2.25 arcmin² field centred on the quasar. In particular, we find 15–18 galaxies that have colours consistent with being a population of passively evolving massive ellipticals at the quasar redshift. They form 'fingers' in the V − K K , I − K K colour–magnitude plots at V − K ≃6.9, I − K ≃4.3 comparable to the red sequences observed in other z ≃1.2 clusters. We find suggestive evidence for substructure among the red sequence galaxies in the K image, in the form of two compact groups, 40 arcsec to the north, and 60 arcsec to the south-east of the quasar. An examination of the wider optical images indicates that this substructure is significant, and that the clustering extends to form a large-scale structure 2–3  h ⁻¹ Mpc across. We find evidence for a high (≳50 per cent) fraction of blue galaxies in this system, in the form of 15–20 'red outlier' galaxies with I − K >3.75 and V − I <2.00, which we suggest are dusty, star-forming galaxies at the quasar redshift. Within 30 arcsec of the quasar we find a concentration of blue ( V − I <1) galaxies in a band that bisects the two groups of red sequence galaxies. This band of blue galaxies is presumed to correspond to a region of enhanced star formation. We explain this distribution of galaxies as the early stages of a cluster merger which has triggered both the star formation and the quasar.  相似文献   

Propagation invariants, reflection and transmission in anisotropic, laterally heterogeneous media     

B. L. N. Kennett  K. Koketsu  A. J. Haines 《Geophysical Journal International》1990,103(1):95-101

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