空间VLBI观测量估计大地测量

介绍了研究空间VLBI在大地测量等领域应用的意义,探讨了空间VLBI的观测量类型、观测模型及其涉及的大地测量所关心的参数;并采用1980～2004年的VLBI观测数据进行了计算,对大地测量所关心的几种参数的计算结果进行了分析.     

空间VLBI观测量估计大地测量参数的模拟计算

介绍了研究空间VLBI在大地测量等领域应用的意义，探讨了空间VLBI的观测量类型、观测模型及其涉及的大地测量所关心的参数；并采用1980～2004年的VLBI观测数据进行了计算，对大地测量所关心的几种参数的计算结果进行了分析。     

联合平差中大地测量观测值的数学模型

本文引入了摄影测量与非摄影测量观测值联合平差中大地测量观测值的严密数学模型——三维大地测量模型和常规的近似模型,针对这两种模型的局限性,提出了适合于联合平差的准三维大地测量模型。     

基于GML 3.0的大地测量数据建模

分析了GML 3.0对空间数据建模的支持,讨论了基于GML 3.0的大地测量数据建模,包括大地测量坐标参考系、大地测量观测值的模型描述,给出了基于GML 3.0的大地测量对象建模实例。     

论大地测量研究青藏高原地学问题的方法

结合青藏高原地质构造背景及大地测量观测值特点，讨论了青藏高原区域地壳运动模型的建立，提出用大地测量资料结合地质，地球物理资料反演青藏高原构造应力场的方法。     

大地测量反演线弹性构造应力场

本文基于地表大地测量位移观测值，提出用大地测量监测资料反演线弹性构造应力场方法。讨论了大地测量监测点分布式、观测随机误差以及岩体介质参数对边界力系数反演值的影响，为实际应用大地测量资料反演线弹性构造应力场提供了参考依据。     

大地测量学科发展现状与趋势

近50年,由于大地测量观测手段的不断进步和应用领域的不断拓展,大地测量学科不断进化,并与其他学科不断交叉与融合。本文首先简述了大地测量学发展的背景和在历史上发挥的主要作用,梳理了大地测量传统学科的形成。进一步,分析了大地测量发展现状,侧重从观测手段的进步描述学科的发展;从应用领域的拓展描述交叉学科的形成;从国家需求和科学发展出发,描述了大地测量学科未来的发展趋势。最后,综合各方面因素,提出了大地测量现阶段学科分类建议,试图为大地测量工作者的科研选题、基金申请提供借鉴。     

论大地测量研究青藏高原地学问题的方法

结合青藏高原地质构造背景及大地测量观测值特点，讨论了青藏高原区域地壳运动模型的建立，提出用大地测量资料结合地质、地球物理资料反演青藏高原构造应力场的方法。     

大地测量数据采集的集成技术

本文在分析了当前大地测量数据采集模式之后，提出了运用接口技术，对多源多格式的大地测量外业观测数据进行集成的解决方案。通过相应接口文件的分析设计，得到了大地测量数据采集的数据模型，并据此制定出大地测量控制网接口文件的数据格式，从而归纳了现有大多数大地测量观测数据的电子手簿格式，为大地测量数据共享平台的信息共建提供了技术保障。     

四维整体大地测量实用模型及观测方程

顾及时空几何及物理效应的四维整体大地测量,给大地测量提出了许多新的研究课题,同时也为大地测量开辟了新的应用前景。本文从实用观点出发,建立了四维整体大地测量实用模型,并给出了地面观测值的观测方程。在所有观测方程中,都以点位速率和重力位速率为未知数,以便减少观测值的历元归算;而且随着观测历元的增加,速率参数的精度将不断提高。     

扰动重力场精密确定与逼近效果分析

介绍了局部重力场逼近的点质量方法;详细论述了组合点质量模型的构制方法;利用实测重力异常数据建立了某区域组合点质量模型;分析了各层点质量的散射误差、逼近效果、随高度的变化特征。结果表明,组合点质量模型能以较高精度逼近外部扰动重力场。     

三维激光扫描技术在铁路危岩体监测中的应用

铁路设计施工中,铁路沿线危岩体的情况对铁路线位的走向及施工有着重要的影响,因此,对铁路沿线危岩体的监测,是铁路勘测中相当重要的工作。但山区的危岩体的监测工作难度大,且危险性高,传统测量方法无法完成。三维激光扫描技术出现,以其高效性、高精度、远距离非接触测量等优势弥补了传统危岩体监测方法的缺点。本文探讨了如何应用三维激光扫描技术对铁路沿线的危岩体进行监测分析的方法。     

Inter-annual water mass variations from GRACE in central Siberia

Our study analyses satellite and land-based observations of the Yakutsk region centred at the Lena watershed, an area characterised mainly by continuous permafrost. Using monthly solutions of the Gravity Recovery And Climate Experiment satellite mission, we detect a mass increase over central Siberia from 2002 to 2007 which reverses into a mass decrease between 2007 and 2011. No significant mass trend is visible for the whole observation period. To further quantify this behaviour, different mass signal components are studied in detail: (1) inter-annual variation in the atmospheric mass, (2) a possible effect of glacial isostatic adjustment (GIA), and (3) hydrological mass variations. In standard processing the atmospheric mass signal is reduced based on the data from numerical weather prediction models. We use surface pressure observations in order to validate this atmospheric reduction. On inter-annual time scale the difference between the atmospheric mass signal from model prediction and from surface pressure observation is $<$ 4 mm in equivalent water height. The effect of GIA on the mass signal over Siberia is calculated using a global ice model and a spherically symmetric, compressible, Maxwell-viscoelastic earth model. The calculation shows that for the investigated area any effect of GIA can be ruled out. Hence, the main part of the signal can be attributed to hydrological mass variations. We briefly discuss potential hydrological effects such as changes in precipitation, river discharge, surface and subsurface water storage.     

地质灾害群测群防系统设计与实现

通过对于地质灾害群测群防县(市)级、乡镇级、村级三级监测网络体系的研究,建立了地质灾害群测群防体系机制模型,并围绕群测群防体系建设的监测、管理与专业调查3项任务,设计了与群测群防体系机制相适应的地质灾害群测群防系统结构,形成了"隐患点信息查看─灾情信息采集与上传─灾情信息接收与处置"的群测群防业务链;据此业务链,基于智能手机探讨了有关地质灾害群测群防系统的功能实现。以黔东南苗族侗族自治州地质灾害群测群防调查数据为试验数据进行了应用试验,试验结果表明:该系统实现了群测群防"监测"与"管理"两项任务的有机结合,可以为地质灾害群测群防常态化监测与应急处置提供技术支持。     

面向网络的海量影像空间数据在线分发技术

阐述了基于J2EE的海量空间数据在线分发系统原理和关键技术，给出了海量影像空间数据在线浏览发布的实例。     

数据质量聚类算法

在聚类算法中,聚类中心决定聚类的最终结果,而传统的分割聚类算法不能准确定位聚类中心。根据数据场提出了数据质量聚类中心的新概念,给出数据质量聚类算法,能够一次定位聚类中心,无需迭代,也无需预置聚类个数。7组对比实验表明,提出的方法能够准确定位聚类中心,获得良好的聚类结果和稳定性,优于传统的分割聚类算法和峰值密度聚类算法。     

城市轨道交通工程隧道施工贯通误差测量精度设计与探讨

城市轨道交通工程隧道施工测量的一项主要任务是保证隧道贯通,其贯通误差的大小将直接影响到轨道交通工程建设质量和工程造价,因此在轨道交通工程测量精度设计中,科学合理地规定隧道贯通误差及其允许值,是轨道交通工程测量的一项重要研究任务。本文从城市轨道交通工程贯通误差的概念、城市轨道交通工程隧道贯通误差的限值的分析确定、城市轨道交通工程贯通测量及误差分配三个部分对城市轨道交通工程贯通误差测量精度要求进行了分析和阐述,供广大测量工作者参考。     

Mass Balance Estimation of Dokriani Glacier in Central Indian Himalaya Using Remote Sensing Data

Dokriani Glacier is regarded as one of the important glaciers of Bhagirathi River basin, which fed river Ganges. The length of the glacier is about 4.6 km, and snout elevation is about 4028 m m.s.l. The mass balance of this glacier was calculated using field-based measurements for few years during 1994 to 2000. However, due to remote and poor accessibility, the field-based measurements could not continue; thus, remote sensing-based methods become useful tool to estimate the long-term mass balance of the glacier. In this study, glacier mass balance has been determined using accumulation area ratio (AAR) method. Remote sensing data sets, e.g. Landsat TM, ETM?+?and OLI, have been used to estimate AAR for different years from 1994 to 2014. An attempt has also been made to develop a mathematical relationship between remote sensing-derived AAR and field-observed mass balance data of the glacier. Further, this relationship has been used to estimate mass balance of the glacier for different years using remote sensing-derived AAR. Estimated mass balance was validated from ground-observed mass balance for few years. The field-observed and remote sensing-derived mass balance data are compared and showed high correlation. It has been observed that AAR for the Dokriani Glacier varies from 0.64 to 0.71. Mass balance of the glacier was observed between ??15.54 cm and ??50.95 cm during the study period. The study highlights the application of remote sensing in mass balance study of the glaciers and impact of climate change in glaciers of Central Indian Himalaya.     

Detection of Changes in Glacier Mass Balance Using Satellite and Meteorological Data in Tirungkhad Basin Located in Western Himalaya

Himalayan glaciers and their mass balance are poorly sampled through direct mass balance measurements. Thus, based on Landsat datasets of ETM⁺ (2000), ETM⁺ (2006) and TM (2011), mass balance studies of 32 glaciers was carried out using accumulation area ratio (AAR) method in the Tirungkhad river basin, a tributary of Satluj River, located in western Himalayan region. The overall specific mass balance was negative varying from ?27 cm (2000) to ?41 cm (2011). Out of 32 glaciers, 27 glaciers (81.2 %) showed negative mean mass balance and 5 glaciers (18.7 %) showed positive mean mass balance. Mean of specific mass balance for the year 2000, 2006 and 2011 was found to be ?48 cm, ?55 cm and ?0.61 cm respectively, in case of glaciers with negative mass balance while in case of glaciers with positive mass balance, it was 0.67 cm (2000), 0.56 cm (2006) and 0.47 cm (2011). The investigations suggested a loss of ?0.034 km³ of glacial ice for 2000, 0.036 km³ for 2006 and 0.038 km³ for 2011 respectively. The negative mass balance of the glaciers since 2000 correlates well with the increasing trend of annual mean temperature and decreasing trend of precipitation (snow water equivalent (SWE) and rainfall). Based on Mann Kendall test the temperature and SWE trends were significant at 95 % confidence level, however, the rainfall trend was insignificant.     

计算机辅助大型土石方工程计量的方法探索

本文结合西南科技大学新区建设的大型土石方工程计量项目，说明了一套以数字化地形图和高程数据为主要信息源，通过运用南方CASS5．0和EXCEL（XP）软件，用计算机辅助大型土石方工程计量的方法。该方法能高效率、高精度地实现大型土石方工程计量。同时还对大型土石方工程计量过程中的人工干预程度进行了探讨。得出的结论用于指导实践，获得了满意的结果，并为同类型工程积累了经验。