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The managing of information and data between researching groups is critical to the success of any exploration or development project. Poor communication and data sharing between technological departments can result in incomplete interpretations or inaccurate drilling decisions making. According to the statistic results, the time cost in retrieving and collecting data will occupy more than 70 % percent of the total working time of technicians during the petroleum geological researching. This paper is a summary of the characteristics and the development of the Data & Graphic management system for oil & gas exploration.After that the system's application in oil & gas exploration and researching, which has improved the quality and accurateness of mapping has been summarized in detail. The application of the system mentioned above has proved to be very successful in Daqing oilfield. 相似文献
994.
J. Delabrouille J.-F. Cardoso G. Patanchon 《Monthly notices of the Royal Astronomical Society》2003,346(4):1089-1102
We present a new method for analysing multidetector maps containing several astrophysical components. Our method, based on matching the data to a model in the spectral domain, permits us to estimate jointly the spatial power spectra of the components and of the noise, as well as their mixing coefficients. It is of particular relevance for analysis of millimetre-wave maps of cosmic microwave background (CMB) anisotropies. 相似文献
995.
G. Efstathiou 《Monthly notices of the Royal Astronomical Society》2002,332(1):193-198
A principal-component analysis of cosmic microwave background (CMB) anisotropy measurements is used to investigate degeneracies among cosmological parameters. The results show that a degeneracy with tensor modes – the 'tensor degeneracy'– dominates uncertainties in estimates of the baryon and cold dark matter densities, ω b =Ωb h 2 , ω c =Ωc h 2 , 1 from an analysis of CMB anisotropies alone. The principal-component analysis agrees well with a maximum-likelihood analysis of the observations, identifying the main degeneracy directions and providing an impression of the effective dimensionality of the parameter space. 相似文献
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997.
E. Gaztañaga A. Romeo J. Barriga E. Elizalde 《Monthly notices of the Royal Astronomical Society》2001,320(1):12-20
We address the problem of encoding and compressing data dominated by noise. Information is decomposed into 'reference' sequences plus arrays containing noisy differences susceptible to being described by a known probability distribution. One can then give reliable estimates of the optimal compression rates by estimating the corresponding Shannon entropy. As a working example, this idea is applied to an idealized model of the cosmic microwave background (CMB) data on board the Planck satellite. Data reduction is a critical issue in space missions because the total information that can be downloaded to Earth is sometimes limited by telemetry allocation. Similar limitations might arise in remotely operated ground based telescopes. This download-rate limitation could reduce the amount of diagnostics sent on the stability of the instruments and, as a consequence, curb the final sensitivity of the scientific signal. Our proposal for Planck consists of taking differences of consecutive circles at a given sky pointing. To a good approximation, these differences could be made independent of the external signal, so that they are dominated by thermal (white) instrumental noise, which is simpler to model than the sky signal. Similar approaches can be found in other individual applications. Generic simulations and analytical predictions show that high compression rates, can be obtained with minor or zero loss of sensitivity. Possible effects of digital distortion are also analysed. The proposed scheme is flexible and reliable enough to be optimized in relation to other critical aspects of the corresponding application. For Planck , this study constitutes an important step towards a more realistic modelling of the final sensitivity of the CMB temperature anisotropy maps. 相似文献
998.
Minoru Ando Tetsuya Nagata Shuji Sato Makoto Watanabe Kunio Itoh Toshihide Kawai Hidehiko Nakaya Yoshiharu Namba Takeshi Takezawa 《Experimental Astronomy》2002,13(3):119-134
We constructed a wide field cryogenic telescope (WFCT) containing a whole Ritchey-Chrétien system and a focal plane array
in a cryostat for near infrared observations to cover the field of view of 0.4°. The telescope has a primary mirror of 220
mm and an engineering grade 256 × 256 InSb array. The optical components such as two mirrors, filters, spiders, and radiation
shield tube are cooled down to 180 K as well as the InSb array to 35 K by a mechanical refrigerator. We show the results of
the background surface brightnesses and the limiting magnitudes at 3.3 and 3.67 μm measured at Sutherland, South Africa. We
describe the on-going upgrade of this instrument, equipped with a 1024 × 1024 ALADDIN InSb science grade array.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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