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Relations between the Spectral Indices and Flux Densities of Eight Blazars 八种Blazar的光谱指数与通量密度的关系
IF 1.4 4区 物理与天体物理 Q3 ASTRONOMY & ASTROPHYSICS Pub Date : 2019-05-02 DOI: 10.1155/2019/8041087
Yu-hai Yuan
<jats:p>Relations between the flux densities (<jats:italic>F</jats:italic>) and spectral indices (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mrow><mml:mi mathvariant="normal">α</mml:mi></mml:mrow></mml:math>) can help us analyze the emission process. In this paper, we choose 8 blazars (0235+164, 0430+052, 1156+295, 3C345, 1308+326, 1413+135, 3C454.3, and 1749+096) from the University of Michigan Radio Observatory (UMRAO) database to study the relations between the spectral indices (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M2"><mml:mrow><mml:mi mathvariant="normal">α</mml:mi></mml:mrow></mml:math>) and flux densities at 14.5GHz (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M3"><mml:mrow><mml:msub><mml:mrow><mml:mi>F</mml:mi></mml:mrow><mml:mrow><mml:mn mathvariant="normal">14.5</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>). The main results are the following. (1) There are strong anticorrelations between <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M4"><mml:mrow><mml:mi mathvariant="normal">α</mml:mi></mml:mrow></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M5"><mml:mrow><mml:msub><mml:mrow><mml:mi>F</mml:mi></mml:mrow><mml:mrow><mml:mn mathvariant="normal">14.5</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>, with the correlation coefficient<jats:italic> r</jats:italic> in the range from <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M6"><mml:mo>-</mml:mo><mml:mn mathvariant="normal">0.33</mml:mn></mml:math> to <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M7"><mml:mo>-</mml:mo><mml:mn mathvariant="normal">0.87</mml:mn></mml:math>. (2) The <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M8"><mml:mi mathvariant="normal">α</mml:mi><mml:mo>-</mml:mo><mml:msub><mml:mrow><mml:mi>F</mml:mi></mml:mrow><mml:mrow><mml:mn mathvariant="normal">14.5</mml:mn></mml:mrow></mml:msub></mml:math> distributions show elliptic appearance, which have been fitted by elliptic curves. (3) For most of the sources, the time intervals of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M9"><mml:mi mathvariant="normal">α</mml:mi><mml:mo>-</mml:mo><mml:msub><mml:mrow><mml:mi>F</mml:mi></mml:mrow><mml:mrow><mml:mn mathvariant="normal">14.5</mml:mn></mml:mrow></mml:msub></mml:math> elliptic circle (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M10"><mml:mrow><mml:msub><mml:mrow><mml:mi>T</mml:mi></mml:mrow><mml:mrow><mml:mi>c</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:math>) are consistent with the quasi-periodicities calculated by the averaged light curves and spectral variances (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M11"><mml:mrow><mml:msub><mml:mrow><mml:mi>P</mml:mi></mml:mrow><mml:mrow><mml:mi mathvariant="normal">α</mml:mi><mml:mover accent="false"><mml:mrow><mml:mi>F</mml:mi></mml:mrow><mml:mo>¯</mml:mo></mml:mover></mml:mrow></mml:msub></mml:mrow></mml:mat
通量密度(F)和光谱指数(α)之间的关系可以帮助我们分析发射过程。本文选取美国密歇根大学射电天文台(UMRAO)数据库中的8个blazar(0235+164、0430+052、1156+295、3C345、1308+326、1413+135、3C454.3和1749+096),研究了它们在14.5GHz (F14.5)波段的光谱指数(α)与通量密度的关系。主要结果如下。(1) α与F14.5呈较强的负相关,相关系数r在-0.33 ~ -0.87之间。(2) α-F14.5的分布呈椭圆形,经椭圆曲线拟合。(3)对于大多数光源,α-F14.5椭圆圆(Tc)的时间间隔与平均光曲线和光谱方差(p - α f¯)计算的准周期性一致。
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引用次数: 0
Oscillating Cosmological Solutions in the Modified Theory of Induced Gravity 修正诱导引力理论中的振荡宇宙学解
IF 1.4 4区 物理与天体物理 Q3 ASTRONOMY & ASTROPHYSICS Pub Date : 2019-04-24 DOI: 10.1155/2019/1502453
F. Zaripov
This work is the extension of author’s research, where the modified theory of induced gravity (MTIG) is proposed. In the framework of the MTIG, the mechanism of phase transitions and the description of multiphase behavior of the cosmological scenario are proposed. The theory describes two systems (stages): Einstein (ES) and “restructuring” (RS). This process resembles the phenomenon of a phase transition, where different phases (Einstein’s gravitational systems, but with different constants) pass into each other. The hypothesis that such transitions are random and lead to stochastic behavior of cosmological parameters is considered. In our model, effective gravitational and cosmological “constants” arise, which are defined by the “mean square” of the scalar fields. These parameters can be compared with observations related to the phenomenon of dark energy. The aim of the work is to solve equations of MTIG for the case of a quadratic potential and compare them with observational cosmology data. The interaction of fundamental scalar fields and matter in the form of an ideal fluid is introduced and investigated. For the case of Friedmann-Robertson-Walker space-time, numerical solutions of nonlinear MTIG equations are obtained using the qualitative theory of dynamical systems and mathematical computer programs. For the case of a linear potential, examples joining of solutions, the ES and RS stages, of the evolution of the cosmological model are given. It is shown that the values of such parameters as “Hubble parameter” and gravitational and cosmological “constants” in the RS stage contain solutions oscillating near monotonically developing averages or have stochastic behavior due to random transitions to different stages (RS or ES). Such a stochastic behavior might be at the origin of the tension between CMB measurements of the value of the Hubble parameter today and its local measurements.
本文是作者在前人研究基础上的延伸,提出了修正的感应重力理论。在MTIG的框架下,提出了相变机制和宇宙场景多相行为的描述。该理论描述了两个系统(阶段):爱因斯坦(ES)和“重构”(RS)。这个过程类似于相变现象,不同的相(爱因斯坦的引力系统,但具有不同的常数)相互传递。考虑了这种跃迁是随机的并导致宇宙学参数的随机行为的假设。在我们的模型中,产生了有效的引力和宇宙学“常数”,它们由标量场的“均方”定义。这些参数可以与观测到的暗能量现象进行比较。这项工作的目的是解决二次势情况下的MTIG方程,并将其与观测宇宙学数据进行比较。介绍并研究了以理想流体形式存在的基本标量场与物质的相互作用。对于friedman - robertson - walker时空情况,利用动力系统定性理论和数学计算机程序,得到了非线性MTIG方程的数值解。对于线性势的情况,给出了宇宙学模型演化的ES和RS阶段解连接的例子。结果表明,RS阶段的“哈勃参数”、引力和宇宙学“常数”等参数的值包含在单调发展平均值附近振荡的解,或者由于随机过渡到不同阶段(RS或ES)而具有随机行为。这种随机行为可能是今天哈勃参数的CMB测量值与其局部测量值之间紧张关系的根源。
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引用次数: 4
Study of Chang’E-2 Microwave Radiometer Data in the Lunar Polar Region 嫦娥二号月球极区微波辐射计数据研究
IF 1.4 4区 物理与天体物理 Q3 ASTRONOMY & ASTROPHYSICS Pub Date : 2019-04-24 DOI: 10.1155/2019/3940837
Fan Yang, Yi Xu, K. Chan, Xiaoping Zhang, G. Hu, Yong Li
The Chang’E-2 (CE-2) four-channel microwave radiometer (MRM) data with frequencies of 3 GHz, 7.8 GHz, 19.35 GHz, and 37 GHz have been used to investigate the properties of lunar surface such as regolith thickness, dielectric constant, and titanium abundance within a depth of several meters in middle and low latitudes. The purpose of this work is to take a close look at MRM data in the polar regions of the Moon and analyze the characteristics of the brightness temperature (TB) in permanently shadowed regions (PSRs), especially where evidence of water ice has been found. First, the comparisons of brightness temperature values in the polar region and in low latitudes show that (1) the periodic diurnal (day/night) variation of TB becomes weak in high latitudes since topography plays a dominant role in determining TB in polar region and (2) seasonal effects are more recognizable in polar region than in low latitudes due to the weak illumination condition. Second, even without direct sun illumination, significant seasonal variations of TBs are observed in PSRs, probably caused by the scattering flux from neighboring topography. TB Ratio (TBR) between channel 1 and channel 4, which indicates the differences of TB at different depths of lunar regolith, is higher and shows stronger seasonal variation in PSR than regions with direct illumination. Third, overall the distribution of high TBR values is in consistence with the water ice distributions obtained by the Moon Mineralogy Mapper instrument, the LAMP UV spectra, and the Lunar Prospector Neutron Spectrometer. The proportion of the summation over area with water ice proof in the regions of interest is 0.89 and 0.56 in south pole and north pole, respectively. The causes of the correlation of high TBR between different microwave frequencies and stability of water ice deposits still require further investigation, but MRM data shows unique characteristic in PSRs and could provide important information about the upper few meters of lunar regolith.
利用嫦娥二号四通道微波辐射计(MRM) 3 GHz、7.8 GHz、19.35 GHz和37 GHz频率数据,对中低纬度地区数米深度的月表风化层厚度、介电常数和钛丰度等特性进行了研究。这项工作的目的是仔细研究月球极地地区的MRM数据,并分析永久阴影区域(PSRs)的亮度温度(TB)特征,特别是在已经发现水冰证据的地方。首先,极地地区与低纬度地区的亮度温度值对比表明:(1)高纬度地区由于地形对极地地区结核病的决定起主导作用,结核病的周期性日/夜变化减弱;(2)由于光照条件较弱,极地地区的季节性影响比低纬度地区更明显。其次,即使没有太阳直射,PSRs中TBs也有明显的季节变化,这可能是由邻近地形的散射通量引起的。通道1和通道4的TB比(TBR)较高,且PSR的季节性变化较强,反映了月壤不同深度下TB的差异。第三,总体而言,高TBR值的分布与月球矿物绘图仪、LAMP紫外光谱和月球勘探者中子星获得的水冰分布一致。南极和北极的水防冰面积占感兴趣区域总和的比例分别为0.89和0.56。不同微波频率与水冰沉积物稳定性之间高TBR相关性的原因仍需进一步研究,但MRM数据在psr中显示出独特的特征,可以提供有关月球上层几米风化层的重要信息。
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引用次数: 10
Mass Transfer and Intrinsic Light Variability in the Contact Binary MT Cas 接触二元MT-Cas中的传质和本征光变率
IF 1.4 4区 物理与天体物理 Q3 ASTRONOMY & ASTROPHYSICS Pub Date : 2019-04-04 DOI: 10.1155/2019/4593092
H. Dai, Huiyu Yuan, Yuangui Yang
First CCD photometry for the contact binary MT Cas is performed in 2013 in December. The spectral type of F8V is determined from the low-precision spectrum observed on 2018 Oct 22. With Wilson-Devinney code, the photometric solutions are deduced from VRc light curves (LCs) and AAVSO’s and ASAS-SN’s data, respectively. The results imply that MT Cas is a W-type weak-contact binary with a mass ratio of q=2.365(±0.005) and a fill-out factor of f=16.6(±1.2)%, respectively. The asymmetric LCs in 2013 are modeled by a dark spot on the more massive component. By analyzing the (O-C) curve, it is discovered that the orbital period may be undergoing a secular increase at a rate of dP/dt=1.12(±0.09)×10-8d  yr-1, which may result from mass transfer from the less massive component to the more massive one. With mass transferring, MT Cas may evolve into a broken-contact configuration as predicted by TRO theory.
2013年12月,首次对接触二元MT Cas进行了CCD光度测量。F8V的光谱类型是根据2018年10月22日观测到的低精度光谱确定的。利用Wilson-Devinney编码,分别从VRc光曲线(lc)和AAVSO和ASAS-SN的数据推导出光度解。结果表明,MT - Cas为w型弱接触双星,质量比q=2.365(±0.005),填充因子f=16.6(±1.2)%。2013年的不对称lc是由更大质量成分上的一个黑点模拟的。通过对(O-C)曲线的分析,发现轨道周期可能以dP/dt=1.12(±0.09)×10-8d yr-1的速率长期增加,这可能是质量从质量较小的组分向质量较大的组分转移的结果。随着质量的传递,MT - Cas可能会演变成由TRO理论预测的断接触结构。
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引用次数: 1
Design and Implementation of Xinjiang Astronomical Observatory Astronomical Data Transmission Visualization System 新疆天文台天文数据传输可视化系统的设计与实现
IF 1.4 4区 物理与天体物理 Q3 ASTRONOMY & ASTROPHYSICS Pub Date : 2019-04-02 DOI: 10.1155/2019/8741027
X. Ye, Hailong Zhang, Yan Zhu, Jie Wang, T. Ergesh, Huijuan Li
With the development of astronomical observation technology, astronomical devices produce more data than ever. Astronomical telescopes are usually far away from city, so the long-distance data transmission between telescope and data center faces great challenges. Visualization system of astronomical data transmission with four-layer structure was built to manage data transmission. This visualization system has a four-layer structure: hardware layer, system layer, middle layer, and visualization layer. System function includes automatic data transmission, log recording of transmission process, and display of the transmission status in dynamic web pages. Besides, the middle layer contains an alarm subsystem that can automatically send system exceptions to administrator. We also design corresponding mechanisms to ensure the high stability of the system and to control the data transmission when the network is unstable through adaptive algorithms. In test, this visualization system can run stably for a long time in unmanned manner. This system also provides a solution for the astronomical observation bases to automatically transmit data to the data center.
随着天文观测技术的发展,天文设备产生的数据比以往任何时候都要多。天文望远镜通常离城市较远,因此望远镜与数据中心之间的远距离数据传输面临着很大的挑战。建立了四层结构的天文数据传输可视化系统,对数据传输进行管理。该可视化系统具有四层结构:硬件层、系统层、中间层和可视化层。系统功能包括数据自动传输、传输过程日志记录、动态网页显示传输状态等。此外,中间层还包含一个告警子系统,可以自动将系统异常发送给管理员。我们还设计了相应的机制来保证系统的高稳定性,并通过自适应算法控制网络不稳定时的数据传输。经测试,该可视化系统能在无人状态下长时间稳定运行。该系统还为天文观测基地自动向数据中心传输数据提供了解决方案。
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引用次数: 1
An Introduction to a New Space Debris Evolution Model: SOLEM 一种新的空间碎片演化模型:SOLEM
IF 1.4 4区 物理与天体物理 Q3 ASTRONOMY & ASTROPHYSICS Pub Date : 2019-03-28 DOI: 10.1155/2019/2738276
Xiao-wei Wang, Jing Liu
SOLEM is the first space debris long-term evolution model of China. This paper describes the principles, components, and workflow of the SOLEM. The effects of different mitigation measures based on SOLEM model are analyzed and presented. The limitation of the model is pointed out and its future improvement work-plan is prospected.
SOLEM是中国首个空间碎片长期演化模型。本文介绍了SOLEM的原理、组成和工作流程。分析并介绍了基于SOLEM模型的不同缓解措施的效果。指出了该模型的局限性,并对今后的改进工作计划进行了展望。
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引用次数: 9
Revisiting the Question: The Cause of the Solar Cycle Variation of Total Solar Irradiance 再谈问题:太阳总辐照度太阳周期变化的原因
IF 1.4 4区 物理与天体物理 Q3 ASTRONOMY & ASTROPHYSICS Pub Date : 2019-03-26 DOI: 10.1155/2019/3641204
N. Xiang
The Mg II index and sunspot area are usually used to represent the intensification contribution by solar bright structures to total solar irradiance (TSI) and sunspot darkening, respectively. In order to understand the cause of the solar cycle variation of TSI, we use extension of wavelet transform, wavelet coherence (WTC), and partial wavelet coherence (PWC), to revisit this issue. The WTC of TSI with sunspot area shows that the two time series are very coherent on timescales of one solar cycle, but the PWC of TSI with sunspot area, which can find the results of WTC after eliminating the effect of the Mg II index, indicates that the solar cycle variation of TSI is not related to sunspots on the solar surface. The coherence of two time series at these timescales should be due to a particular phase relation between sunspots and TSI. The WTC and PWC of TSI with Mg II index show that the solar cycle variation of TSI is highly related to Mg II index, which reflects the relation of TSI with the long-term part of Mg II index that shows the intensification contribution by the small magnetic features to TSI. Consequently, the solar cycle variation of TSI is dominated by the small magnetic features on the solar full disk. Additionally, we also show the combined effects of the sunspot darkening and the intensification contribution represented by Mg II index to TSI on timescales of a few days to several months and indicate that the faculae increase TSI and contribute to its variation at these timescales.
Mg指数和太阳黑子面积通常分别代表太阳明亮结构对太阳总辐照度(TSI)和太阳黑子变暗的增强贡献。为了了解太阳周期TSI变化的原因,我们使用了小波变换的扩展、小波相干性(WTC)和部分小波相干性(PWC)来重新审视这一问题。与太阳黑子面积的TSI的WTC表明两个时间序列在一个太阳周期的时间尺度上非常一致,但与太阳黑子面积的TSI的PWC可以在消除Mg II指数的影响后找到WTC的结果,表明TSI的太阳周期变化与太阳表面的黑子无关。两个时间序列在这些时间尺度上的一致性应归因于太阳黑子与TSI之间的特殊相位关系。TSI与Mg II指数的WTC和PWC表明,TSI的太阳周期变化与Mg II指数高度相关,这反映了TSI与Mg II指数长期部分的关系,表明了小磁特征对TSI的强化贡献。因此,TSI的太阳周期变化是由太阳全盘上的小磁特征主导的。此外,在数天至数月的时间尺度上,我们还展示了太阳黑子变暗和Mg指数对TSI的强化贡献的综合效应,并表明在这些时间尺度上,光斑增加了TSI并促进了其变化。
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引用次数: 3
Anthropic Principle’s Predicting Symmetric Distribution Matter Strata, Their Physics Laws, and Verifications 人择原理预测物质层对称分布及其物理规律与验证
IF 1.4 4区 物理与天体物理 Q3 ASTRONOMY & ASTROPHYSICS Pub Date : 2019-03-18 DOI: 10.1155/2019/2501417
Changyu Huang, Yongchang Huang
This paper shows anthropic principle’s predicting symmetric distribution matter strata, their physics laws, and verifications, concretely deduces characteristic time, energy, and temperature expressions at different scales, discovers four interesting invariant quantities, shows homeomorphic theorem of space map, and naturally presents a supersymmetric scale energy. We further discover that any infinitesimal space has the same proportional structure space; namely, they have renormalization group invariance. Consequently, this paper shows that the region of any nth level Plank-scope is from the nth level Planck scale to the (n+1)​th level Planck scale, where the different matters of the nthlevel Planck scale build up the (n+1)th level Planck scale matter. The branches of physics science for this region include the nth level Planck scale matter dynamics and the nth level Planck scale matter group dynamics. The nth level Planck scale matter group dynamics describe how the nth level Planck scale matter constructs the (n+1)th level Planck scale matter and how the different matters of the nth level Planck scale evolve in the group system. This paper discovers that the different matters below Planck scale can exist with our matter world at the same time and same place and may be some candidates for dark matter; furthermore, this paper shows a relative theorem of matter scale: for the world of any nth level, the matters’ sizes are relative, not absolute. Evidently, the discoveries of both the symmetrical distribution scales and the relations among the corresponding different physics laws from infinitesimal to infinitely large scales give a scientific solid development platform for formation of new scientific branches and deeper development of old scientific branches, because we can precisely construct many kinds of scientific theories relevant to all the corresponding matter strata. All the branch sciences of different matter strata up to now naturally need to be included in the framework of the new scientific system of physics.
本文给出了人选原理预测对称分布物质层及其物理规律,并进行了验证,具体推导出了不同尺度下的特征时间、能量和温度表达式,发现了四个有趣的不变量,给出了空间映射的同胚定理,自然地给出了超对称尺度能量。进一步发现,任何无穷小空间都具有相同的比例结构空间;也就是说,它们具有重整化群不变性。因此,本文证明了任何第n级普朗克范围的区域是从第n级普朗克尺度到(n+1)级普朗克尺度,其中第n级普朗克尺度的不同物质构成了第(n+1)级普朗克尺度物质。该领域的物理科学分支包括第n级普朗克尺度物质动力学和第n级普朗克尺度物质群动力学。第n级普朗克尺度物质群动力学描述了第n级普朗克尺度物质如何构建(n+1)级普朗克尺度物质,以及第n级普朗克尺度的不同物质如何在群系统中演化。本文发现普朗克尺度下的不同物质可以与我们的物质世界同时存在于同一地点,可能是暗物质的一些候选者;进一步给出了物质尺度的一个相对定理:对于任何n阶世界,物质的大小都是相对的,而不是绝对的。显然,从无限小到无限大尺度的对称分布尺度和相应的不同物理定律之间关系的发现,为形成新的科学分支和进一步发展旧的科学分支提供了科学坚实的发展平台,因为我们可以精确地构建与所有相应的物质层相关的多种科学理论。到目前为止,所有不同物质层次的分支科学自然都需要纳入物理学新科学体系的框架内。
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引用次数: 0
Comparison of Decadal Trends among Total Solar Irradiance Composites of Satellite Observations 卫星观测太阳总辐射复合物的年代趋势比较
IF 1.4 4区 物理与天体物理 Q3 ASTRONOMY & ASTROPHYSICS Pub Date : 2019-03-10 DOI: 10.1155/2019/1214896
N. Scafetta, R. Willson
We present a new analysis of the two-decade-old controversy over interpretation of satellite observations of total solar irradiance (TSI) since 1978 and the implications of our findings for TSI as a driver of climate change. Our approach compares the methods of constructing the two most commonly referenced TSI composites (ACRIM and PMOD) that relate successive observational databases and two others recently constructed using a novel statistical approach. Our primary focus is on the disparate decadal trending results of the ACRIM and PMOD TSI composite time series, namely, whether they indicate an increasing trend from 1980 to 2000 and a decreasing trend thereafter (ACRIM) or a continuously decreasing trend since 1980 (PMOD). Construction of the four-decade observational TSI composites from 1978 to the present requires the use of results from two less precise Earth Radiation Budget experiments (Nimbus7/ERB and ERBS/ERBE) during the so-called ACRIM-Gap (1989.5–1991.8), between the end of the ACRIM1 and the beginning of the ACRIM2 experiments. The ACRIM and PMOD composites used the ERB and ERBE results, respectively, to bridge the gap. The well-established paradigm of positive correlation between Solar Magnetic Field Strength (SMFS) and TSI supports the validity of the upward trend in the ERB results and the corresponding decadal upward trend of the ACRIM composite during solar cycles 21 and 22. The ERBE results have a sensor degradation caused downward gap trend, contrary to the SMFS/TSI paradigm, that biased the PMOD composite decadal trend downward during solar cycles 21 and 22. The different choice of gap bridging data is clearly the cause of the ACRIM and PMOD TSI trending difference, agreeing closely in both magnitude and direction. We also analyze two recently proposed statistical TSI composites. Unfortunately their methodology cannot account for the gap degradation of the ERBE experiment and their resulting uncertainties are too large to uniquely distinguish between the trending of the ACRIM and PMOD composites. Our analysis supports the ACRIM TSI increasing trend during the 1980 to 2000 period, followed by a long-term decreasing trend since.
本文对自1978年以来关于太阳总辐照度(TSI)卫星观测数据解释的争议进行了新的分析,并对TSI作为气候变化驱动因素的影响进行了分析。我们的方法比较了构建两个最常用的TSI复合材料(ACRIM和PMOD)的方法,这些方法涉及连续的观测数据库和最近使用一种新的统计方法构建的另外两个TSI复合材料。我们主要关注的是ACRIM和PMOD TSI复合时间序列的不同年代际趋势结果,即它们是在1980 - 2000年间呈上升趋势,之后呈下降趋势(ACRIM)还是在1980年以来呈持续下降趋势(PMOD)。构建从1978年至今的40年观测TSI复合数据需要在所谓的ACRIM-Gap(1989.5-1991.8)期间(在ACRIM1结束和ACRIM2开始之间)使用两个不太精确的地球辐射预算实验(Nimbus7/ERB和ERBS/ERBE)的结果。ACRIM和PMOD复合材料分别利用ERB和ERBE的结果来弥补这一差距。太阳磁场强度(SMFS)与TSI正相关的模式支持了ERB结果的上升趋势和相应的ACRIM复合指数在第21和第22太阳周期的年代际上升趋势的有效性。与SMFS/TSI模式相反,ERBE结果有传感器退化导致的下降间隙趋势,使PMOD复合年代际趋势在第21和第22太阳周期下降。间隙桥接数据的不同选择显然是导致ACRIM和PMOD TSI趋势差异的原因,在幅度和方向上都非常接近。我们还分析了最近提出的两种统计TSI复合材料。不幸的是,他们的方法不能解释ERBE实验的间隙退化,其结果的不确定性太大,无法唯一区分ACRIM和PMOD复合材料的趋势。分析表明,1980 ~ 2000年ACRIM TSI呈上升趋势,此后呈长期下降趋势。
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引用次数: 6
Rain Attenuation Study at Ku-Band over Earth-Space Path in South Korea 韩国地空路径ku波段降雨衰减研究
IF 1.4 4区 物理与天体物理 Q3 ASTRONOMY & ASTROPHYSICS Pub Date : 2019-03-03 DOI: 10.1155/2019/9538061
S. Shrestha, Dong-You Choi
Rain attenuation measurement techniques are studied with appropriate prediction of rain attenuation at Ku-band for Koreasat 6. This is accomplished by the establishment of experimental setup in Mokdong at 12.25 GHz link. The databases are analyzed for three years, 2013 till 2015. During observation period, rainfall rate of 50 mm/hr is obtained which is measured by OTT Parsivel showing the signal attenuated by 10.7 dB for 0.01% of the occurrence. Comparison with the measured data demonstrates that the proposed technique provides sufficiently accurate estimation for Ku-band signal attenuation in site specifically whose effectiveness is performed through the statistical analysis against the established rain attenuation models. The proposed technique is judged through the error matrices where relative error margins of 52.82, 4.11, and 23.64% are obtained for 0.1%, 0.01%, and 0.001% of the occurrence.
研究了雨衰减测量技术,并对韩国卫星6号ku波段雨衰减进行了适当的预报。这是通过在木洞建立12.25 GHz链路的实验装置来实现的。数据库的分析时间为2013年至2015年。在观测期间,OTT Parsivel测量的降雨速率为50 mm/hr,在0.01%的发生时间内,信号衰减了10.7 dB。与实测数据的对比表明,该方法对现场ku波段信号衰减有足够准确的估计,并通过对已建立的降雨衰减模型的统计分析来验证其有效性。通过误差矩阵对所提出的技术进行判断,在0.1%、0.01%和0.001%的发生情况下,相对误差范围分别为52.82、4.11和23.64%。
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引用次数: 8
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Advances in Astronomy
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