基于变分多参数正则化方法融合卫星散射计资料

基于常规三维变分同化（3DVAR）思想和反问题中的正则化技术,提出了适用于风场融合的带正则化约束项的3DVAR方法,在南海海域开展数据融合试验,同时采用模型函数方法确定合理的正则化参数,针对一次台风个例进行了QuikSCAT散射计海面风场数据和华南中尺度模式海面风场数据的融合试验,结果表明采用带正则化约束的3DVAR融合方法,明显消除了常规3DVAR方法融合风场时带来的虚假信息,融合后分析风场以及涡度场和散度场分布均匀,结构清晰,气旋中心显著,且分析场中观测起主导作用;采用信号自由度（DFS）方法对融合方法进行定量评估,发现相对常规3DVAR方法,带正则化约束的3DVAR融合系统中观测数据提供的DFS较多,同时提高了观测场对分析场的影响;基于独立观测资料对融合结果进行检验发现相对华南中尺度模式和常规3DVAR方法的统计结果,带正则化约束的3DVAR方法得到的风场具有最小的均方根误差和最大的相关系数。     

一种提高振动源扫描算法信噪比的方法

在对原始数据进行适当光滑的基础上,利用局部极值特性拟合出数据包络线。经地震波形数据计算检验,利用这种包络线可以较好地提高振动源扫描算法(SSA)的信噪比。而对于无源的随机振动,该方法给出的SSA亮点函数高低值较接近,且亮点函数的高值分布随扫描起始时间及扫描长度的变化与有源信号有较明显差异,这也为评价某时刻点上是否存在有源信号提供了一定的判据。     

瞬时应变型岩爆模拟试验中花岗岩主频特征演化规律分析

利用深部岩爆模拟试验系统对花岗岩进行室内瞬时岩爆模拟试验,同时利用声发射系统采集试验过程中声发射信号,得到试验全过程应力和声发射波形信息时域图。结合声发射累计能量曲线特征,找到5个关键拐点,即花岗岩初始加载能量激增后产生的第一个拐点A、岩爆发生前两次明显的上升台阶处拐点B和C、岩爆发生时的能量突跃点D、最终峰值点E。将关键点处波形信号从全时域波形中提取出来并进行快速傅里叶变换,得到各关键点二维功率谱图,结果表明：花岗岩声发射主频值在加载初期时为106 kHz,随着荷载的增加,频率由低频向高频过渡,频带变宽且由单峰向多峰转化,频率成分复杂预示多种破裂模式的发生。岩爆前和最终岩爆时刻频带又变窄并恢复单峰,主频值降低至与初始加载时一致,约为106 kHz,预示着岩爆时刻花岗岩岩石高能量的释放。     

Use of cyanobacteria for in-situ resource use in space applications

The regolith of other planetary bodies, such as the Moon and Mars, is rich in inorganic elements that could potentially be exploited for space applications. Lithotrophic microorganisms that are capable of utilising rocks as a growth substrate, and facilitate the extraction of elements, are ideal candidates for in-situ resource use. Of particular interest are the cyanobacteria, which have been suggested for applications, such as oxygen, fuel and biomass production, nutrient acquisition, and feedstock provisions. In this study, Gloeocapsa strain OU_20, isolated from a rock-dwelling community exposed to low Earth orbit; Leptolyngbya strain OU_13 and Phormidium strain OU_10, both isolated from a rock-dwelling community exposed to Mars simulated conditions; Chroococcidiopsis 029; Arthrospira platensis; Synechococcus elongatus; and Anabaena cylindrica, were examined as potential organisms for space in-situ resource use. Volcanic rocks, including basalt (low in SiO₂) analogous to martian and lunar basalt, rhyolite (high in SiO₂), and anorthosite analogous to lunar regolith were used as growth substrates. The growth rate and rock dissolution were significantly lower with rhyolite demonstrating the importance of silica content in defining the potential for in-situ resource use. Biological weathering resulted in the release of bio-essential elements from the rock matrix, highlighting the potential of cyanobacteria for applications such as bio-mining and nutrient acquisition, on other planets. A. cylindrica produced the maximum biomass with the three rock-types and the optimal value was obtained with the basalt. Exposure experiments demonstrated that A. cylindrica, Chroococcidiopsis 029, Gloeocapsa strain OU_20, Phormidium strain OU_10, and Leptolyngbya strain OU_13 were able to survive 28 days of exposure to desiccation and Mars simulated conditions, which is beneficial in case of system malfunction and for storage. The results from this study indicate that cyanobacteria can potentially be used for in-situ planetary resource acquisition.     

海上地震勘探斜缆采集中鬼波产生机理及压制效果分析

在海洋油气勘探中,为了准确获取勘探目的 层高精度、高分辨率的反射信息,实现更加细腻的成像,海洋地震宽频采集及处理技术近年来得到了极大的创新和发展.本文研究了海洋地震勘探中鬼波的产生机理、鬼波的分类和特性及其在实际地震资料中的表现形式.采用频率域高精度斜缆Radon变换作为主要处理方法,对某直斜缆宽频数据进行了鬼波的衰减...     

Mooring system of ocean turbulence observation based on submerged buoy

A comparison experiment has been taken in the Kiaochow Bay between a newly designed mooring turbulence observation instrument (MTOI) and microstructure profiler MSS60 made by Sea & Sun. The whole observing system is based on a submerged buoy, in which the turbulence observation instrument is embedded, with a streamline-shape floating body, which is made of buoyancy material of glass microsphere. For the movement of seawater and the cable shaking strongly anytime influence the behaviors of the floating body, the accelerate sensors are used for the vibration measurement in the instrument together with the shear probe sensor. Both the vibration data and the shear data are acquired by the instrument at the same time. During data processing, the vibration signals can be removed and leave the shear data which we really need. In order to prove the reliability of the new turbulence instrument MTOI, a comparison experiment was designed. The measuring conditions are the same both in time and space. By this way, the two groups of data are comparable. In this paper, the conclusion gives a good similarity of 0.93 for the two groups of shear data in dissipation rate. The processing of the data acquired by MTOI is based on the cross-spectrum analysis, and the dissipation rate of it matches the Nasmyth spectrum well.     

城市空间三维数据快速提取与更新研究

数字城市是信息时代发展的必然产物,城市建模是数字城市的重要内容。空间数据采集是城市建模中最关键的部分。但受技术水平的限制,我国的城市三维空间数据获取能力还相对比较薄弱。本文论述了城市三维空间数据提取与更新的方法,并对摄影测量与三维激光扫描方法的发展前景作了展望。     

大气遥感双视场米散射激光雷达信号拼接

介绍了一种双视场米散射激光雷达信号拼接方法。主要思想是寻找近场和远场信号都具有高信噪比的最佳拼接区域,求解该区域两种信号之间的函数关系,自动实现激光雷达近场信号与远场信号的有效拼接和反演。拼接结果兼具近场信号探测盲区低和远场信号探测高度高的优点。反演结果表明,该方法能够准确有效地实现双视场信号拼接,并能反演得到高精度的气溶胶光学特性。     

天宝TrimbleGeoXR在高尔夫球场数字化建模中的应用前景

全面介绍了天宝（Trimble）VRS技术和高性能的天宝TrimbleGeoXR网络RTK流动站的测量系统,论述了测量系统应用于高尔夫球场数字化建模的优势,并展望了其应用前景。     

两颗GPS现代化卫星L5载波信号的比较

本文分析了GPS现代化信号L5载波的结构及相对于非现代化信号的改进,比较了GPS L5载波和WAAS L5载波的区别;比较了2颗现代化卫星SVN49和SVN62播发的L5载波的信号结构及信噪比,结果表明:SVN49播发的L5载波演示信号的抗干扰能力较差,而SVN62播发的L5载波具有更强的抗干扰能力,满足设计规范要求。