Multidetector multicomponent spectral matching and applications for cosmic microwave background data analysis     

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   

Principal-component analysis of the cosmic microwave background anisotropies: revealing the tensor degeneracy     

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=Ω_b  h ²  ,   ω _c=Ω_c  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   

濮阳市地热资源分析及水文地质参数计算     

李莲花  张建斌  张连胜  郭建伟 《河南国土资源》2001,(4)

本文搜集濮阳地区有关勘探资料和地热深井互阻、多孔抽水试验资料 ,通过综合分析、计算 ,阐述了濮阳市地热资源的地质背景并给出了水文地质参数 ,为濮阳市地热资源的合理开发提供基础地质依据  相似文献   

Processing and compression of noise-dominated data: application to the cosmic microwave background data on board the Planck satellite     

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   

Construction of Wide Field Cryogenic Telescope     

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   

Discriminating between unresolved point sources and 'negative' Sunyaev–Zel'dovich clusters in cosmic microwave background maps     

J. A. Rubiño-Martín  R. A. Sunyaev 《Monthly notices of the Royal Astronomical Society》2003,344(4):1155-1174

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Wilkinson Microwave Anisotropy Probe data and the curvature of space     

Jean-Philippe Uzan  Ulrich Kirchner  George F. R. Ellis 《Monthly notices of the Royal Astronomical Society》2003,344(4):L65-L68

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Filtering techniques for the detection of Sunyaev–Zel'dovich clusters in multifrequency maps     

D. Herranz  J. L. Sanz  M. P. Hobson  R. B. Barreiro  †  J. M. Diego  E. Martínez-González  A. N. Lasenby 《Monthly notices of the Royal Astronomical Society》2002,336(4):1057-1068

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基于C#语言的国(境)外地震背景信息交互式产出系统     

马秀丹  陈姝荞  龙海云  张晋辉 《地震地磁观测与研究》2021,42(1):162-168

针对国(境)外地震专报产出过程中遇到的信息搜索困难、内容不规范、难以满足时效性等问题,基于C#编程语言,设计开发了国(境)外地震专报背景信息交互式产出系统。该系统只需值班人员少许的参与,自动获取人口信息、海啸信息、震中附近一定范围内的历史地震目录,生成地震的人口伤亡信息,最终产出word格式的地震专报。  相似文献   

新疆于田地区背景地震与触发地震活动分析     

张盛峰  张永仙  庄建仓 《地震地磁观测与研究》2021,42(2):123-124

正新疆于田地区历史上发生过多次6.0级以上地震,北京时间2020年6月26日在此地区再次发生MS 6.4地震。震后,中国地震局地震预测研究所紧急开展地震应急会商,并组织多家单位针对此次地震开展了虚拟科考工作。其中,所发生的地震是否属于其他强震的余震,与历史上已发生的多个强震存在怎样的关系,或者还是属于独立的背景地震活动,  相似文献