BDS中长基线三频RTK算法研究

针对BDS中长基线RTK定位中整周模糊度受大气延迟误差影响难以正确固定的问题,提出一种BDS中长基线三频整周模糊度确定方法。采用MW组合确定B2-B3超宽巷整周模糊度,利用B2-B3超宽巷和B1-B3宽巷组合观测值所受电离层延迟误差较接近的特点,确定B1-B3宽巷整周模糊度。利用无电离层组合解算窄巷整周模糊度和相对天顶对流层延迟误差,最终实现实时动态定位。利用实测的BDS中长基线进行算法验证,结果表明,该方法可有效固定中长基线三频载波相位整周模糊度,获得cm级定位精度。     

电离层残差辅助北斗三频伪距载波相位组合周跳探测

提出一种基于单差模型的电离层残差辅助伪距相位组合周跳探测方法。基于北斗三频实测数据,以波长、电离层延迟系数与噪声为约束条件,优化选取3个线性无关的超宽巷（EWL）、宽巷（WL）组合(0,-1,1)、(1,4,-5)、(4,-2,-3), 并利用伪距相位组合法进行周跳的探测与修复。实验结果表明,这3个组合甚至可以实时探测出原始频点上1周的小周跳。针对三频伪距相位组合周跳探测法可能出现的误探情况,提出利用电离层残差法辅助三频伪距相位组合周跳探测的方法,即首先利用原始观测量求出历元间电离层残差,再将相邻历元间所求的历元间电离层残差二次作差。实验表明,该方法可以实时准确地探测与修复不同基线下单差的各类大小周跳。     

北斗三频载波伪距组合观测值的周跳探测算法研究

针对BDS全星座播发三频信号的特点,利用1个三频载波伪距组合(1,4,-5)和2个三频无几何相位组合(1,1,-2)、(1,-2,1)联合的方法进行周跳探测,并结合最小2-范数确定整数周跳的搜索策略。实测数据表明,该方法对一般周跳、不敏感周跳及连续随机周跳均有较好的探测与修复效果。     

联合北斗优选MW组合和无几何相位组合实时探测和修复三频周跳

针对使用B1和B2频点组成的MW观测值受噪声误差和电离层延迟误差影响较大的问题,提出使用B2和B3频点观测值组成弱电离层超宽巷MW组合的方法。联合优选的北斗MW组合和2个弱电离层的无几何相位组合（1,0,－1）和（0,1,－1）进行周跳探测和修复实验。结果表明,采用B2和B3频点观测值组合的MW组合伪距噪声更小、探测精度更优,有利于周跳的探测和修复。     

基于Grubbs准则和区间搜索的双频GPS周跳探测

GPS周跳是影响监测成果精度的重要因素之一,其多值性及如何判断各自频率上的周跳尤为重要.本文针对双频周跳探测,以△Φ= ΔN1-(λ2/λ1)ΔN2为主方程,提出一种通过Grubbs准则探测ΔN1、ΔN2异常值的方法来约束双频周跳△N1、ΔN2的搜索范围,通过计算满足主方程整数解的方式探测周跳.通过采样率为1 s、5 ...     

GNSS基线向量与点位协方差传播方法的等价性

在GNSS控制网平差和点位测量中,需将GNSS基线向量协方差和点位协方差在不同坐标系间进行传播。推导了GNSS基线向量协方差从高斯平面直角坐标系到大地坐标系、再到空间直角坐标系的严密和简化传播公式,研究了GNSS基线向量协方差和点位协方差传播的等价性和统一性。理论和算例证明,推导的传播公式是正确的,可用点位协方差传播公式代替复杂的基线向量协方差传播公式,基线向量协方差和点位协方差在空间直角坐标系与高斯平面直角坐标系间的传播,都可统一到形式简单的空间直角坐标系与站心直角坐标系间的传播。     

回归支持向量机在区域高程异常拟合中的应用

一、引言 上世纪90年代, Vapnik等人通过对机器学习的深入研究,将Vapnik本人创立的统计学习理论（Statistical Learning Theory,SLT）即有限样本学习理论,及相关概念-VC维（VC Dimension）、结构风险最小化准则（ Structural Risk Minimization, SR M）、核函数（ Kernel Function）引入到机器学习领域,提出了有限样本学习条件下,解决模式识别、回归分析问题时,通过黑箱模型建立“输入”和“输出”的“泛函”关系,并且使得模型具有较强“泛化”能力的支持向量机（Support Vector Machine,SVM）模型。空间高程异常拟合计算模型是以有限数量的已知点的大地经纬度（B,L）作为已知的输入量,空间点位的大高与该点的水准高的差值（H大地高-h水准高）作为输出量构成的分析样本,通过机器学习建立空间点位的大地经纬度（B,L）和该点高程异常值之间精确的“黑箱”关系,应用于空间样本点区域范围内及周边区域高程异常空间变化求解。     

星载GPS相位非差观测粗差和周跳的探测与修复

提出了以历元间星载GPS载波相位观测值之差作为观测量,结合拟准检定法（QuAD）来探测和修复非差星载GPS相位观测值中的粗差和周跳的方法。利用仿真低轨卫星GPS相位观测数据,对粗差和周跳的特性进行了分析,并对探测和修复步骤与效果进行了详细说明。实验表明,该方法不仅计算简捷,而且能有效修复非差载波相位观测值中的粗差和周跳,为非差星载GPS精密单点定轨提供了良好的质量控制基础。     

重力仪垂直标定基线(武汉)

国家地震局地震研究所(中国武汉)(ISSSB)和汉诺威大学大地测量研究所(联邦德国汉诺威)(IFE)合作在武汉建立了一条用于拉柯斯特一隆贝格(简称LCR)重力仪标定的垂直标定基线。这条基线由20(10~(-5)m/S~2)和2(10~(-5)m/S~2)的二部份组成,前者共有19个站,后者11个站。该标定基线布设在武汉一座高层建筑里。为了获得所用重力仪的长波和中波的标定参数,在北京、武汉、广州三个绝对重力点间进行了飞机联测,在总段差为230(10~(-5)m/S~2)的庐山重力基线的24个测站上进行了联测。所有这些观测使用了6台LCR重力仪。平差后重力段差达到的精度对庐山基线优于±5(10~(-8)m/S~2),垂直基线优于±2(10~(-8)m/S~2)。     

长基线时间序列季节项提取和重构方法分析

运用经验模态分解（EMD）、集合经验模态分解（EEMD）和完备总体经验模态分解（CEEMD）3种方法对原始基线时间序列进行分解,得到各自时间序列的本征函数模态分量（IMF）、相关系数及周期性强度,进而确定其季节项分量,同时通过比较季节项和原始基线时间序列的叠加功率谱图优选分解方法。结果表明,CEEMD方法对基线时间序列季节项提取和重构效果最佳。     

Thermohaline structure inhomogeneity associated with polynia at the northern margin of Emery Ice-shelf

Based on the hydrographic data in austral summer during the 22nd Antarctic Expedition of China(2005/2006),some features can be found about the northern margin of Emery ice shelf as follows.The heat content in the surface layer(0-50 m) at the eastern end and the western end of the ice-shelf margin is much higher than that at the middle.The upper mixing-layer depth and the seasonal thermocline depth at the middle of the ice-shelf northern margin are much shallower than those at the both ends.However there is much less difference between the middle and the ends in the bottom layer.The remote sensing photos show that the inhomogeneity in the surface-layer water is closely related to the spatial distribution of the floes and polynia in the area.     

Phylogenetic analysis of cultivable bacteria isolated from Arctic sea-ice

Phylogenetic analysis based on 16S rDNA of 8 strains of cultivable bacteria isolated from Arctic sea-ice was studied.The results showed that strain BJ1 belonged to genus Planococcus,which was a genus of low mole percent G C gram-positive bacteria;strain BJ6 belonged to genus Burkholderia of β-proteobacteria and the rest 6 strain all belonged to γ-proteobacteria,of which strain BJ8 was a species of Pseudoalteromonas,strain BJ2-BJ5 and BJ7 were members of genus Psychrobacter.Phylogenetic analysis also indicated that bacteria of genus Psychrobacter of the isolates formed a relatively independent phylogenetic cluster in comparison with other bacteria belonged to genus Psychrobacter.     

Information for authors

正1 Aims and Scope Advances in Polar Science(APS)is an international,peer-reviewed journal jointly sponsored by the Polar Research Institute of China and the Chinese Arctic and Antarctic Administration.APS is a comprchensive academic journal dedicated to presentation of multi-disciplinary achievements in Arctic and Antarctic expeditions and research.Its primary purpose is to publish achievements in fundamental research,applied     

Advances in Polar Science CONTENTS(Volume 25,2014)

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Guide to Authors： Journal of Mountain Science

<正>AIMS AND SCOPE(Editorial Policy)The Journal of Mountain Science(JMS)is devoted to mountains and their surrounding lowlands-ecoregions of particular global importance,with a particular emphasis on the important highlands/mountains in the world,such as the Tibetan Plateau,the Himalayas,the Alps,the Andes,the Rockies and many other mountain ranges of our planet.     

Journal of Mountain Science(JMS)

<正>The Journal of Mountain Science(JMS),founded in2004,is an international English-language journal on mountain sciences.JMS is supervised by the Chinese Academy of Sciences(CAS),sponsored by the Chengdu Institute of Mountain Hazards and Environment,CAS,published by Science Press China,and distributed by Springer exclusively throughout the world(excluding Mainland China).The JMS is published bimonthly,fulltexted in SpringerLink and CNKI,indexed/abstracted by     

Relationship of Arctic sea ice and Northern Hemispheric 500 hPa Polar vortices

Using the NCEP/NCAR reanalysis monthly 500 hPa height data on a 2.5 latitude-longitude grid and 1°×1° sea ice data,the polar vortex area,intensity index and arctic sea ice area index are calculated respectively,and the meridional distribution,period variation and the abrupts in the long range trend are analyzed to study their relationship.The results show that the meridional distribution of sea ice and polar vortex h-ave distinctive difference,the relative positions of them are different in the eastern and western hemispheres,and exept they have periods of 4 months,quasi half year,quasi year,4-5 years and 10 years commonly,and each of them has its own respective variation as well.The sea ice area is decreasing apparently since 1980's,so is the polar vortex area,but their abrupt changge time are different totally.The area of sea ice and polar vortex has prominent positive correlation,but the relationship of sea ice intensity,polar vortex intensity,polar vortex area is complicated.     

Preliminary study on plasma membrane fluidity of Psychrophilic Yeast Rhodotorula sp.NJ298 in low temperature

The ability of cell to modulate the fluidity of plasma membrane was crucial to the survival of microorganism at low temperature. Plasma membrane proteins, fatty acids and carotenoids profiles of Antarctic psychrophilc yeast Rhodotorula sp. NJ298 were investigated at -3 ℃, 0 ℃ and 8 ℃. The results showed that plasma membrane protein content was greater at -3 ℃ than that at 8 ℃, and a unique membrane polypeptide composition with an apparent molecular mass of 94.7 kDa was newly synthesized with SDS-PAGE analysis; GC analysis showed that the main changes of fatty acids were the percentage of unsaturated fatty acids (C18∶ 1 and C18∶ 2) and shorter chain saturated fatty acid (C10∶ 0) increased along with the decrease of the culture temperature from 8 ℃ to -3 ℃; HPLC analysis indicated that astaxanthin was the major functional carotenoids of the plasma membrane, percentage of which increased from 54.6±1.5% at 8 ℃ to 81.9±2.1% at -3 ℃. However the fluidity of plasma membrane which was determined by measuring fluorescence anisotropy was similar at -3 ℃, 0 ℃ and 8 ℃. Hence these changes in plasma membrane's characteristics were involved in the cellular cold-adaptation by which NJ298 could maintain normal plasma membrane fluidity at near-freezing temperature.     

Author Index for Journal of Mountain Science Volume 11,2014,pp 1-1656

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