星载远紫外极光/气辉探测发展综述

地球热层和电离层是近地卫星运行的主要场所,也是空间天气对人类活动影响的重要区域.气辉和极光是高层大气中的重要发光现象,其辐射特性、特别是紫外波段的辐射特性,是高层大气和电离层物理化学过程信息的重要来源、本文详细分析了国外远紫外极光/气辉探测和相应探测器的发展里程,并结合我国相关研制技术和水平,提出了发展星载极光/气辉探测的基本考虑和建议.     

电离层LBH日辉辐射大视场计算方法

LBH日辉辐射是由光电子与氮气分子碰撞激发而产生的,是电离层在远紫外辐射波段中最强的分子辐射信号.从空间对电离层LBH日辉辐射进行成像观测为高层大气状态的监测提供了一种强有力的方法.本文分析了LBH辐射的谱带特征,采用电子碰撞直接激发理论,使用球几何大气模型,针对大视场观测模式,给出了一种改进的LBH日辉柱辐射率计算方法RAURIC.RAURIC针对AURIC辐射算法的局限性主要有两点改进：一是增加了观测方位角;二是考虑了沿观测视线LOS方向上太阳天顶角的变化.我们使用RAURIC计算了140~180 nm波段的LBH日辉辐射,并与AURIC进行了比较,结果表明：在天底方向上,二者具有非常好的一致性;在其他观测方向上,尤其在大视场观测模式下,则需要使用RAURIC进行计算.本文工作为电离层LBH日辉图像模拟技术与数据反演技术的研制奠定了基础.     

远紫外光谱遥感反演电离层EDP技术

本研究基于美国GUVI观测氧原子135.6 nm夜气辉光谱数据,建立了GUVI临边观测模型,采用正则化和牛顿迭代法相结合的方法,消除了权重矩阵的病态问题,得到了峰值电子密度和峰值高度,并结合电离层电子密度的Chapman表达式,反演得到了电离层电子密度剖面.将得到的反演结果与地基方式获取的观测数据进行比较,两者吻合得很好.之后,反演得到了磁暴期2002年9月29日到10月3日的电子密度剖面,初步分析了电离层电子密度剖面随磁暴的变化情况.     

一次中强磁暴期间低纬电离层响应的CT成像

为考察赤道异常区电离层对中等强度磁暴的响应特性,用电离层ＣＴ成像方法重建电离层电子密度二维剖面．重建结果表明,暴时低纬电离层电子密度以降低为主,但暴相随纬度和高度而异;磁暴期间,赤道异常峰结构仍然存在,但恢复相期间峰的位置向赤道移动;磁暴急始之后约２０ｍｉｎ,在赤道异常峰区出现电子密度深度耗空,这种耗空遍及从底到顶的整个Ｆ区,朝赤道一侧显现水平梯度非常大的陡壁．这种与磁暴急始相联系的电子密度深度耗空现象很有意义,值得进一步研究．     

一次中强磁暴期间低纬电离层响应的CT成像

为考察赤道异常区电离层对中等强度磁暴的响应特性,用电离层ＣＴ成像方法重建电离层电子密度二维剖面．重建结果表明,暴时低纬电离层电子密度以降低为主,但暴相随纬度和高度而异;磁暴期间,赤道异常峰结构仍然存在,但恢复相期间峰的位置向赤道移动;磁暴急始之后约２０ｍｉｎ,在赤道异常峰区出现电子密度深度耗空,这种耗空遍及从底到顶的整个Ｆ区,朝赤道一侧显现水平梯度非常大的陡壁．这种与磁暴急始相联系的电子密度深度耗空现象很有意义,值得进一步研究．     

地震电离层探测技术及其应用研究进展

2017年即将发射的中国电磁监测试验卫星将填补地震电离层立体监测体系中不可或缺的空白区域,也将为天地一体化地震电磁对比校验及圈层耦合机理认识提供重要的科学支撑.针对近期地震电离层立体监测体系发展的需求,本文主要介绍了目前国内用于地震研究的地基及空基电离层探测技术,包括电离层垂测/斜测、甚低频(VLF)电波观测、舒曼谐振观测、GPS及空间卫星电磁等,并总结了各种探测技术在国内外地震应用研究中的进展; 最后结合不同探测手段的优势,探讨了地震电磁立体探测系统的构建,并就未来的多手段综合应用发展提出了建议.      

地震-电离层扰动探测技术的研究进展

回顾了地震-电离层扰动机理的研究进展和主要的数据观测方法,总结了地震电磁卫星观测电离层扰动的应用发展情况以及基于卫星测量数据对异常辐射源定位的研究进展,介绍了无线电探测方法的实验情况和数据分析方法,为未来中国探测电离层扰动进行短临地震预测工作提出了建议.     

声波远探测技术概述及发展

常规测井项目探测井外信息较浅,难以反映地质异常体距井外较远距离发育情况.声波远探测技术提出已近30年,商业化研究也有10余年,可以对井外数十米甚至上百米范围进行探测,该技术产生大大丰富了研究领域,已经发展成一种油气勘探行业中不可缺少的先进技术.声波远探测测井主要可以分为单极子反射纵波远探测和偶极子反射横波远探测,其中,单极子反射纵波远探测以斯伦贝谢为代表,偶极子反射横波由贝克休斯为代表,本文在描述了声波远探测基本概念的基础上,分别对两种远探测方法从国内外发展角度进行了概述,概述内容主要方面有:基本原理发展过程、仪器研发思路、处理方法改进及相关难点,对各科研院所及单位的研发现状进行总结,对偶极子反射横波远探测的优势进行了说明.通过油田应用情况进行分析,概括了远探测测井的主要作用,对偶极子远探测技术最新进展及相关应用实例进行了阐述,最后在分析远探测技术发展现状和趋势基础上,给出应用前景展望.     

数字化X线成像技术

X线数字化技术是当前医学影像领域最新最重要技术之一,本文简要介绍X线数字化成像技术的现状,并阐述了间接数字化X线成像技术和直接数字化X线成像技术的各种类型及原理。     

利用高频返回散射技术探测远地核爆炸电离层效应

本文叙述利用高频返回散射技术探测我国1976年的一次低空大当量核爆炸电离层效应的结果。返回散射探测设备设于离爆炸点2205km的新乡。本文得到了核爆炸产生的附加电离区和电离层扰动的参数。这些结果与爆炸区附近其他手段观测的结果相符。     

A comparison of space-based observations of the energy budgets of the mesosphere and the troposphere

The flow of energy from the Sun, through the atmosphere, to the Earth's surface and oceans, and ultimately back to space, controls the weather and climate of the planet. Since the dawn of the Space Age, the energy balance of the planet has been measured by orbiting satellites. Over the past 40 years the technology and the scientific understanding have developed to the point where we can measure not only the energy balance of the entire Earth and its atmosphere but also of the various regions of the atmosphere including the troposphere, the stratosphere, and the mesosphere. With the planned space-based observations of the sources and sinks of energy in the mesosphere, the energy balance of this region of the atmosphere may soon be better understood from observations than the energy balance of the troposphere on seasonal to annual timescales. Fundamental to this assertion is the fact that the primary sources and sinks of radiative and chemical potential energy, the thermal structure, and the winds in the mesosphere are to be directly observed by space-based instrumentation at high vertical resolution, in contrast to the troposphere. In this paper we review some of the planned measurements of the energy budgets of the atmosphere from existing and future space-based platforms. We particularly show how the airglow can be used to determine many of the key sources of energy in the mesosphere. These ideas provide the basis for interpretation of new space-based measurements of the mesosphere planned in the near future.     

News from the Lower Ionosphere: A Review of Recent Developments

Current knowledge concerning the lower ionosphere (D- and E-region) is reviewed with an emphasis on new aspects of empirical results. Starting with an overview of experimental techniques and corresponding data bases, both regarding charged as well as the most relevant neutral constituents of this altitude range, the ionospheric variability is discussed both concerning regular (e.g. diurnal and seasonal) as well as irregular variations (e.g. driven by the variability of nitric oxide). We then turn to ‘new players’ in the lower ionosphere, i.e. charged aerosol particles such as mesospheric ice particles in noctilucent clouds or polar mesospheric summer echoes and meteor smoke particles originating from ablated meteoric matter. These species have received considerable attention in recent years, in part because it is speculated that observations of their properties might be useful for the detection of climate change signals. The available experimental data base regarding these species is reviewed and we show that there is now compelling evidence for the ubiquitous presence of these very heavy charge carriers throughout the lower ionosphere. While many fundamental details regarding these charged species are not yet completely understood, this emphasizes that charged aerosol particles may not be neglected in a comprehensive treatment of the lower ionospheric charge balance and related phenomena. Finally, we close with suggestions for future research.     

Photochemistry of Ions at D-region Altitudes of the Ionosphere: A Review

The current state of knowledge of the D-region ion photochemistry is reviewed. Equations determining production rates of electrons and positive ions by photoionization of atmospheric neutral species are presented and briefly discussed. Considerable attention is given to the progress in the chemistry of O⁺(⁴S), O⁺(²D), O⁺(²P), N⁺, N₂ ⁺, O₂ ⁺, NO⁺, N₄ ⁺, O₄ ⁺, NO⁺(N₂), NO⁺(CO₂), NO⁺(CO₂)₂, NO⁺(H₂O) _n for n = 1–3, NO⁺(H₂O)(N₂), NO⁺(H₂O)₂(N₂), NO⁺(H₂O)(CO₂), NO⁺(H₂O)₂(CO₂), O₂ ⁺(H₂O), H₃O⁺(OH), H⁺(H₂O) _n for n = 1–8, O^?, O₂ ^?, O₃ ^?, O₄ ^?, OH^?, CO₃ ^?, CO₄ ^?, NO₂ ^?, NO₃ ^?, ONOO^?, Cl^?, Cl^?(H₂O), Cl^?(CO₂), HCO₃ ^?, CO₃ ^?(H₂O), CO₃ ^?(H₂O)₂, NO₃ ^?(H₂O), NO₃ ^?(H₂O)₂, OH^?(H₂O), and OH^?(H₂O)₂ ions. The analysis of the D-region rocket ion mass spectrometer measurements shows that, among these ions, O₂ ⁺, NO⁺, NO⁺(H₂O), and H⁺(H₂O) _n for n = 1–7 can make the main contribution to the total positive ion number density, and O^?, O₂ ^?, Cl^?, OH^?(H₂O), CO₃ ^?, HCO₃ ^?, NO₃ ^?, ONOO^?, CO₄ ^?, NO₃ ^?(H₂O), NO₃ ^?(H₂O)₂, and ³⁵Cl^?(CO₂) ions can be responsible for the main contribution to the total negative ion number density. Photodetachment of electrons from O^?, Cl^?, O₂ ^?, O₃ ^?, OH^?, NO₂ ^?, and NO₃ ^?, dissociative electron photodetachment of O₄ ^? and OH^?(H₂O), and photodissociation of O₃ ^?, O₄ ^?, CO₃ ^?, CO₄ ^?, ONOO^?, HCO₃ ^?, CO₃ ^?(H₂O), NO₃ ^?(H₂O), O₂ ⁺(H₂O), O₄ ⁺, N₄ ⁺, NO⁺(H₂O), NO⁺(H₂O)₂, H⁺(H₂O) _n for n = 2–4, NO⁺(N₂), and NO⁺(CO₂) are studied, and the photodetachment and photodissociation rate coefficients are calculated using the current state of knowledge on the cross sections of these processes and fluxes of solar radiation.     

Ion Chemistry of the Ionosphere at E- and F-Region Altitudes: A Review

The current state of knowledge of E- and F-region ion chemistry is reviewed. Considerable attention is given to the progress in the chemistry of unexcited N₂ ⁺, O₂ ⁺, NO⁺, O⁺(⁴S), N⁺, H⁺, He⁺, Fe⁺, Mg⁺, Na⁺, Ca⁺, and K⁺ ions and electronically excited O⁺(²D), O⁺(²P), O⁺(⁴P), and $ {\text{O}}^{ + } (^{2} {\text{P}}^{*} ) $ ions. Achievements in our understanding of the role of vibrationally excited N₂ ⁺, O₂ ⁺, and NO⁺ ions in the ionosphere are discussed.     

表层多次波成像方法技术研究

在处理表层多次波比较发育的地震数据资料时,和常规将多次波作为噪音进行压制和去除的思路不同,本文提出利用表层多次波来进行地震构造成像的方法技术流程.首先基于互相关技术将表层多次波转化为准一次波,在利用准一次波进行偏移成像之前,提出应用局部倾斜叠加变换的方法,压制由于其特殊的构建过程而常常伴随准一次波的背景干涉噪音,提高准一次波数据的信噪比;然后应用扩展的分步傅里叶偏移方法对去噪后的准一次波数据进行成像,此偏移成像方法在实现分步傅里叶方法时选取多个背景参考速度,不仅继承常规分步傅里叶偏移方法稳定高效,没有有限差分计算存在的频散影响的特点,而且可以增强常规分步傅里叶偏移方法处理复杂陡倾构造的能力.通过数值模拟数据测试,说明本文提出的这一套利用表层多次波进行复杂地下构造成像的方法技术的可行性和有效性.     

Improvement of Nakamura technique by singular spectrum analysis

In this work we investigate the application of the Singular Spectrum Analysis to improve Nakamura Technique. The SSA has a wide and multidisciplinary range of applications; it allows a time series to be decomposed into different components, e.g. the signal itself, as well as various noise components, which can be subsequently removed from the data. Removal of the minor component of the data can lead to significant improvements in the identification of the system. In this paper the use of SSA Technique allows to optimize the signal to noise ratio before computing the classical Nakamura spectral ratios. A number of typical applications are also presented.     

Long-Term Variations in the Parameters of the Middle and Upper Atmosphere and Ionosphere (Review)

Geomagnetism and Aeronomy - The article reviews the main publications from the last eight years on long-term trends in the parameters of the middle atmosphere, thermosphere, and ionosphere. It is...     

楼板谱研究述评

介绍了楼板谱方法的发展与研究现状。详细阐述了主附结构系统的相互作用、调谐、非经典阻尼、多点支撑等动力特性问题,分别介绍了传统楼板谱与新型楼板谱以及多维地震动下楼板谱的研究方法,给出了有待进一步研究的课题。