星载重力测量和固体地球的透视

为了进一步改进地球重力场模型 ,美国科学院 (NRC)于 1997年提出一个报告 ,号召美国和欧洲学者们组成一个由空间探测地球重力场委员会。他们评比了大约 10个计划的或想象的卫星重力任务 ,最后提出了 5种卫星重力任务的方案 ,称为专用重力任务。本文介绍这 5种任务的内容以及地球科学将由这些任务获得重大进展的研究领域。     

光束法平差简史与概要

光束法平差是当前摄影测量和计算机视觉及机器人领域通用的一种利用影像进行定位的理论与方法。自诞生以来,通过多个学科学者的共同努力,其在理论上和方法上都有了全面和完备的发展,也备受多个交叉学科学者的关注。首先试图从历史发展的角度,介绍光束法平差的起源、模型的建立及其扩展,然后讨论其处理系统误差和粗差的方法及其解算方法。时间跨度大致涵盖光束法平差发展的60 a,涉及的贡献主要来自摄影测量,但也包括了大地测量、计算机视觉和机器人领域的代表性工作。最后指出当前光束法平差的几个发展动态。文末附有光束法平差涉及的几个相关人物的简介。     

Proof of concept of a novel cloud computing approach for object-based remote sensing data analysis and classification

Advances in the development of Earth observation data acquisition systems have led to the continuously growing production of remote sensing datasets, for which timely analysis has become a major challenge. In this context, distributed computing technology can provide support for efficiently handling large amounts of data. Moreover, the use of distributed computing techniques, once restricted by the availability of physical computer clusters, is currently widespread due to the increasing offer of cloud computing infrastructure services. In this work, we introduce a cloud computing approach for object-based image analysis and classification of arbitrarily large remote sensing datasets. The approach is an original combination of different distributed methods which enables exploiting machine learning methods in the creation of classification models, through the use of a web-based notebook system. A prototype of the proposed approach was implemented with the methods available in the InterCloud system integrated with the Apache Zeppelin notebook system, for collaborative data analysis and visualization. In this implementation, the Apache Zeppelin system provided the means for using the scikit-learn Python machine learning library in the design of a classification model. In this work we also evaluated the approach with an object-based image land-cover classification of a GeoEye-1 scene, using resources from a commercial cloud computing infrastructure service provided. The obtained results showed the effectiveness of the approach in efficiently handling a large data volume in a scalable way, in terms of the number of allocated computing resources.     

Using horizontal and vertical building structure to constrain indirect sensor orientation

This paper presents a method to integrate linear horizontal, vertical and right-angled scene structures into the bundle adjustment of image sequences. An increasing number of airborne image acquisition systems is available and equipped with non-metric small- or medium-frame cameras and no or insufficiently accurate INS devices. In cases where the data is to be used for the production of geo-spatial data, where a certain accuracy and precision is required, an indirect sensor orientation, possibly including self-calibration, needs to be performed. The idea which led to the presented approach is to reduce the number of GCPs necessary for this task by applying the mentioned scene structures. The method directly uses the linear structures, visible at man-made objects as fictive observations within the adjustment, while self-calibration of intrinsic camera parameters and lens distortion is included as well.Experiments with two datasets demonstrate that, through this method, only limited GCP information is required to obtain satisfactory results. In fact, in one experiment using oblique images, several scene constraints were provided and only the datum was defined by ground control. The residuals at check points from this setup were similar to the traditional case where several well-distributed GCPs were available in the scene. In the second experiment the ability of this approach to support the bundle adjustment was shown for a UAV dataset. Although no GCP and camera calibration information was available, the visual inspection of adjusted object points and the residuals at horizontal structures confirmed the ability of the method to align an image block with the structure, as embodied in the defined scene constraints. Despite the convincing outcome of the experiments, it needs to be mentioned that some manual work is still involved in defining the constraints. In future work the issue of automation will be addressed.     

西藏班公湖-怒江板块结合带岩金遥感找矿模式

西藏班公湖-怒江板块结合带地质构造复杂,成矿条件优越,具备形成金矿的地质背景条件,是西藏最具潜力和规模巨大的贵金属成矿带.但由于该区地质工作程度较低和对成矿规律认识不清,至今没有一个可供开发的岩金矿产地.通过班公湖-怒江板块结合带砂金、岩金矿(化)点,地球化学异常和重砂异常的分布并进行控矿因子分析,建立了该带两种岩金遥感找矿模式,通过验证发现该区具有大型远景规模的岩金矿产地,并认为蚀变岩型金矿和穆龙套型金矿是该带最重要的两种矿床类型,具有巨大的找矿潜力.     

On the link between GPS pseudorange noise and day-boundary discontinuities in geodetic time transfer solutions

When neglecting calibration issues, the accuracy of GPS-based time and frequency transfer using a combined analysis of code and carrier phase measurements highly depends on the noise of the GPS codes. In particular, the pseudorange noise is responsible for day-boundary discontinuities which can reach more than 1 ns in the time transfer results obtained from geodetic analysis. These discontinuities are caused by the fact that the data are analyzed in daily data batches where the absolute clock offset is determined by the mean code value during the daily data batch. This pseudorange noise is not a white noise, in particular due to multipath and variations of instrumental delays. In this paper, the pseudorange noise behavior is characterized in order to improve the understanding of the origin of the large day-boundary discontinuities in the geodetic time transfer results. In a first step, the effect of short-term noise and multipath is estimated, and shown to be responsible for only a maximum of 150 ps (picoseconds) of the day-boundary jumps, with only one exception at NRC1 where the correction provides a jump reduction of 300 ps. In a second step, a combination of time transfer results obtained with pseudoranges only and geodetic time transfer results is used to characterize the long-term evolution of pseudorange errors. It demonstrates that the day-boundary jumps, especially those of large amplitude, can be explained by an instrumental effect imposing a common behavior on all the satellite pseudoranges. Using known influences as temperature variations at ALGO or cable damages at HOB2, it is shown that the approach developed in this study can be used to look for the origin of the day-boundary discontinuities in other stations.     

绿洲—荒漠交错带地下水位分布的遥感模型研究

以利用卫星遥感数据评价干旱区绿洲－荒漠交错带地下水位的分布作为主要研究目的，使用波段Landsat-7ETM 图像，用遥感－数学－模型学融合的研究方法，在实地考察地下水位，土壤水分和其他辅助资料的基础上，建立土壤水分和地下水位的实验方程，提出了评价地下水位分布的遥感模型－GLDRS模型。利用GLDRS模型对新疆策勒绿洲－荒漠交错带进行了实地验证，结果表明，研究结果符合实际，GLDRS多波段模型优越单波段模型，理论地下水位和实测地下水位之间的相关系数为0．901。     

Integrating geotechnical and SAR data for the monitoring of underground works in the Madrid urban area: Application of the Persistent Scatterer Interferometry technique

The Differential Interferometric Synthetic Aperture Radar (DInSAR) is a powerful deformation control technique for civil engineering applications. However, the performance definition and limitations of the technique in tunneling works are far from being standardized. This work presents a thorough validation effort of the applicability of the Persistent Scatterer Interferometry (PSI) technique to the Madrid’s M-30 tunneling works. A set of 26 Envisat images, covering from August 2003 to April 2008, were processed with two PSI techniques and the results were validated with on-ground measurements from leveling benchmarks and strips. The comparison of the deformations of more than 1500 control points has led to a global deformation difference of 2.6 mm RMS and 3.5 mm RMS with a coverage of the area of interest with persistent scatterers of 65% and 34% for the two PSI algorithms used. The limitations of the PSI technique when using SAR missions with low revisit time were shown. PSI has proven the potential to complement on ground monitoring techniques in tunneling works as soon as the limitations are overcome.     

地理国情信息支撑下的空间开发适宜性评价

作为主体功能区划的重要基础性工作,空间开发适宜性评价在协调解决城镇化进程中产生的空间开发失控和区域无序竞争等问题方面具有重要意义。本文利用地理国情成果数据、大比例尺基础测绘成果数据和行业专题资料及统计资料,结合GIS分析技术和层次分析方法,在构建适宜榆林市实际的空间开发适宜性评价体系的基础上,详细分析了榆林市空间开发的适宜性。结果表明,榆林市最适宜开发和较适宜开发的区域主要分布在榆林市的西北部地区,占榆林市总面积的18.4%;最不适宜开发和不适宜开发的地区主要分布在榆林市东南部地区,分别占榆林市总面积的39.86%和41.75%。究其原因,可能由于榆林市东南部多为山区、地势复杂,属于地质灾害频发地区,同时该地区人口数量大,导致人均可利用水资源较为匮乏,开发难度较大。     

贝叶斯原理在遥感影像恢复中的应用

总结了遥感影像数据获取、传输和存储过程中引起影像退化的原因。根据信号处理中的概率统计理论,推导出了一种可以不依赖目标成像模型的遥感影像去模糊算法。实验结果表明,该算法具有较强的影像恢复能力和抗噪能力,对于缺乏点扩散函数先验知识的模糊遥感影像更加适用。     

数字化测图中指向箭头的设计

提出在数字化测图的外业编码数据采集过程中,对于未能连线的方向给与一个指向箭头,以便于在内业的地形图编辑中,根据指向箭头进行连线,提高连线率,减小外业作图工作量,提高工作效率。     

关于地理国情要素数据检查的思考

地理国情普查是一项开创性的工作,需要新的思路和方法。本文梳理归纳了作者参与的6批次过程质量监督抽查、西部验收及复核工作中发现的质量问题,并进行了独立的思考,就地理国情要素数据生产过程中易出现的错误及在检查验收中的检查方法、验收尺度进行论述,有助于保证验收尺度的一致性,为后续更好地开展验收、复核工作及地理国情监测提供了思路。     

Analysis of Lighting Changes in the Tourist City Edogawa Using Nighttime Light Data

When assessing remote sensing data, nighttime light data have shortcomings that can be attributed to sensor limitations and the influence of the natural environment. Signal leakage errors in nighttime light data were identified in this study. A regression model was created to reduce signal leakage error by selecting sampling points in coastal area. Lighting variations in Edogawa between 2008 and 2013 were compared based on the Defense Meteorological Satellite Program’s nighttime light data. The lighting variation characteristics in Edogawa from 1992 to 2012 at 5-year intervals were also analyzed. The results show that the 2002 FIFA World Cup held in Japan led Edogawa’s light digital number values to peak in 2002. The annual Edogawa lighting changes from 2007 to 2013 were also explored. The 2008 global financial crisis led to the lowest compounded night light index and average digital number in Edogawa during these 7 years.     

Shorter Notices

Abstract

No statement appears to have been made at the time of why the national survey was put in hand in 1791. How far the Ordnance launched it in furtherance of its own responsibilities for the defence of the realm, and was therefore right to confer on the ordnance survey the prestige of its name, is a question which this article considers.

The Board of Ordnance was a department of state which was already by then two and a half centuries old. Furnishing the ordnance survey with scientific and administrative skills and Ordnance also lumbered it with the political difficulties which led to its own demise.     

CO-Kriging Approach for Cartosat-1 Height Product with ICESat/GLAS Data for Digital Elevation Surface Generation

Nowadays, Geostatistics and its various interpolation techniques have become a major threshold area in the field of research in GIS. In this research work poorly sampled (less accurate height data relative to ICESat/GLAS height data) Cartosat-1 height data has been used with well sampled (more accurate height data relative to Cartosat-1 height data) ICESat/GLAS LiDAR (Light Detection and Ranging) height point data using Cokriging Interpolation technique, to study the effect of ICESat/GLAS on Cartosat-1 height data. Space borne LiDAR data has led researchers to explore its utilities in many applications. Space borne LiDAR data can be acquired through space borne LiDAR sensors also, like; GLAS (Geoscience Laser Altimeter System) system onboard ICESat (Ice, Cloud and land Elevation Satellite) satellite. In this study, it has been tried to apply Cokriging interpolation on two different sources of data sets, with a common variable (elevation) to generate DES and assessment of this surface has been conducted by DGPS data. After optimizing Cokriging parameters, results of digital elevation surface (DES) generated using Cokriging showed that RMSE has been second least than global polynomial in comparison to Kriging interpolation RMSE after being evaluated by GPS values. So, global polynomial as well as cokriging interpolation technique out performs while comparing with kriging technique for DES generation.     

Matlab与Visual C++混合编程处理全站仪数据的方法

内业数据检核中经常要对点的外业实测坐标与内业成图后的坐标进行比较,以此来发现是否出现造点或是点位挪动的情况.同时经处理后的观测数据能直观地得到外业人员想要的三维坐标,可方便地进行下一步的测量工作.以南方全站仪为例,利用Matlab 与visual C++混合编程生成可脱离Matlab环境直接运行的可执行文件,并给出相关...     

The Work of the British Government's Air Survey Committee And its Impact on Mapping in the Second World War

It has been asserted by Clough (1952) , amongst others, that British Military Survey was poorly prepared for the outbreak of war in 1939. An examination of the work carried out between the wars by the Air Survey Committee would seem to contradict that view. In this paper, the work of the Air Survey Committee is discussed and a brief assessment made of the impact of its work on British mapping during the Second World War.     

数字近景摄影测量建筑容积率调查技术研究

城市建筑容积率是城市土地利用集约化程度的一个重要标志。基于遥感影像进行容积率调查的方法应用范围广,但误差较大。本文将数字近景摄影测量技术应用于精准容积率调查,研究了基于数字地图的单张像片参数以及顾及空间固定条件的立体像对前方交会方法,实现高精度的三维坐标获取。本文将普通数码相机和PDA相结合,辅助以GPS和全站仪等,实现了价格低廉、应用灵活快速的容积率调查集成系统,能够现场完成数据采集、存储。     

竣工测量数据预处理程序设计与实现

本文通过介绍竣工测量工作的作业方法和规范要求,结合当前北京市竣工测量外业测量和内业计算的具体方法,针对传统内业数据处理方法的缺陷,提出了一种竣工测量数据预处理程序,详细介绍了此程序的的总体设计作业流程以及实现的功能。最后,本文提出此程序在实际生产中的应用,并对程序的系统化设计进行了展望。