测绘专业英语原文和部分翻译(1-39)

Table of Contents

Uuit 1 What is Geomatics? （什么是测绘学） (2)

Unit 2 Geodetic Surveying and Plane Surveying（大地测量与平面测量） (6)

Unit 3 Distance Measurement（距离测量） (10)

Unit 4 Angle and Direction Measurement（角度和方向测量） (14)

Unit 5 Traversing （导线测量） (17)

Unit 6 Methods of Elevation Determination（高程测量方法） (21)

Unit 7 Robotic Total Station （智能型全站仪） (25)

Unit 8 Errors in Measurement（测量工作中的误差） (29)

Unit 9 Basic Statistical Analysis of Random Errors (32)

Unit 10 Accuracy and Precision （准确度和精度） (35)

Unit 11 Least-Squares Adjustment (38)

Unit 12 Geodesy Concepts (40)

Unit 13 Geoid and Reference Ellipsoid (42)

Unit 14 Datums, Coordinates and Conversions (44)

Unit 15 Map Projection (46)

Unit 16 Gravity Measurment (48)

Unit 17 Optimal Design of Geomatics Network (50)

Unit 18 Construction Layout （施工放样） (53)

Unit 19 Deformation Monitoring of Engineering Struvture (56)

Unit 20 Understan ding the GPS（认识GPS） (59)

Uuit 21 Understanding the GPS (II) 认识GPS(II) (62)

Unit 22 Competition in Space Orbit（太空轨道上的竞争） (64)

Unit 23 GIS Basics（GIS 的基础） (69)

Unit 24 Data Types and Models in GIS GIS中的数据类型和模型 (75)

Unit 25 Digital Terrain Modeling（数字地面模型） (79)

Unit 26 Applications of GIS (83)

Unit 27 Developments of photogrammetry (87)

Unit 28 Fundamentals of Remote Sensing （遥感的基础） (90)

Unit 29 Digital Image Processing and Its Applications in RS (94)

Unit 30 Airborne Laser Mapping Technology（机载激光测图技术） (99)

Unit 31 Interferometric SAR(InSAR) (102)

Unit 32 Brief Introduction toApplied Geophysics (104)

Unit 33 Origon of Induced Polarization (105)

Unit 34 International Geoscience Organization (108)

Unit 35 Prestigious Journals in Geomatics (110)

Unit 36 Relevant Surveying Instrument Companies (115)

Unit 37 Expression of Simple Equations and Scientific Formulsa (116)

Unit 38 Professional English Paper Writing (119)

Unit 39 Translation Techniques for EST (127)

Uuit 1 What is Geomatics? （什么是测绘学）

Geomatics Defined（测绘学定义）

Where does the word Geomatics come from?（Geomatics－测绘或地球空间信息学，这个名词是怎么来的呢？）GEODESY+GEOINFORMATICS=GEOMA TICS or GEO- for earth and –MATICS for mathematical or GEO- for Geoscience and -MATICS for informatics. （大地测量学＋地理信息学＝GEOMATICS 测绘学或者geo 代表地球，matics 代表数学，或者geo 代表地球科学，matics 代表信息学）It has been said that geomatics is many things to many people.（据说测绘学这个词对不同的人有不同的理解）The term geomatics emerged first in Canada and as an academic discipline; it has been introduced worldwide in a number of institutes of higher education during the past few years, mostly by renaming what was previously called “geodesy” or “surveying”, and by adding a number of computer scienceand/or GIS-oriented courses.（这个术语【term 术语】作为一个学科【academic discipline 学科】第一次形成【emerge】于加拿大；在过去的几年里被全世界的许多高等教育研究机构所熟知，通常是以前的“大地测量学” 或“测量学”在引入了许多计算机科学和GIS 方向【或“基于GIS” 】的课程后重新命名的。）Now the term includes the traditional surveying definition along with surveying steadily increased importance with the development of new technologies and the growing demand for a variety of spatially related types of information, particularly in measuring and monitoring our environment.（随着新技术的发展和不断增长的对空间关系的信息类型的需求，尤其是在测量和监测我们的环境方面【环境监测】，现在，传统测量学定义连同【along with】日益【steadily 稳定的】增长的测量的重要性一起包含在这个术语里了。【逗号后面的句子修饰demand】）Increasingly critical are areas of expanding populations, appreciating land values, dwindling natural resources, and the continuing stressing of the quality of our land, water and air from human activities. （日益增长的危机来自人口扩张，地价上涨，资源紧缩【紧张】，还有由于人类活动引起的土地、水、空气质量的持续的压力【由人类活动带来的土地、水、空气质量的恶化】As such, geomatics bridges wide arcs from the geosciences through various engineering sciences and computer sciences to spatial planning, land development and the environmental sciences.（这样，测绘学在地球科学，各种工程学【engineering sciences 工程学】，计算机科学，空间规划，土地开发和环境科学相互之间架起了广泛的桥梁。）Now the word geomatics has been adopted by several international bodies including the International Standards Organization(ISO),so it is here to stay.（现在geomatics 这个词已经被包括ISO【国际标准化组织】在内的数个国际机构【international bodies】所采用，因此它就这样被普遍接受【be here to stay 习惯用语“被普遍接受” 】The term “surveyor” is traditionally used to collectively describe those engaged in the above activities. （surveyor 这个词按惯例用来总指（这换成“总称”较好）【collectively 全体的】那些从事上述活动的人。）More explicit job descriptions such as Land Surveyor, Engineering Surveyor or Hydrographic Surveyor for example, are commonly used by practitioners to more clearly describe and market their specialized expertise. （更具体的【explicit 清楚的、直接的】工作如土地测量员、工程测量员和水道测量员，【commonly 一般一般地】被业内人士【practitioners 从业者】用来更准确的描述他们的专门技术。【直译为：更清楚的工作描述就如如土地测量员、工程测量员和水道测量员，一般被从业者用来更准确的描述他们的专门技术。）】The term geomatics is a recent creation to convey the true collective and scientific nature of these related activities and has the flexibility to allow for the incorporation of future technological developments in these fields.（geomatics 这个术语是个新词，表达【convey 传达】了实体集合和它们相关联【related】的活动的自然科学，并使这些领域的未

来技术发展的结合【incorporation 结合】成为可能。【flexibility 弹性、机动性】）Adoption of the term also allows a coherent marketing of the profession to industry and schools on a worldwide basis. （这个术语的采用同时也在全世界范围里为行业【industry】里和学校建立了【allow 允许了】一个一致的【coherent】专业市场）As a result, both course and award titles in the traditional Land Surveying sector at many of the world’ s leading universities are being ch anged to “Degree in Geomatics”. （结果，世界上许多一流大学的传统的测量专业【部门】的无论是课程还是授予资【授予学位名称】格都改为“测绘学位” 【Degree in Geomatics】的了）This does not suggest the demise of the term “surveyor” and graduates will still practice as land surveyors or photogammertrists, etc. as appropriate to their specialization.（这并不意味着“surveyor” 这个词的消亡，测绘毕业生还将从事适合他们专业的【as appropriate to their specialization】土地测量员、摄影测量员及其他【ect.】的工作）In the last decade, there has been dramatic development and growth in the use of hardware and software solutions to both measure and process geo-spatial data.（在过去的十年中，在应用硬件和软件的方法【solution 解决方法】来测量和处理地球空间数据工作时有着戏剧性的发展和增长）the use of 在使用…… [in 时] This has created and will continue to create new areas of application, with associated job opportunities for suitably qualified graduates. （创造并将继续创造新的应用【application】领域，并为合适的、合格【qualified 有资格的】的毕业生提供相关的【associated】工作。）As a result, the role of the “surveyor” is expanding beyond traditional areas of practice, as described above, into new areas of opportunity.（结果是，“surveyor”的角色大大超越传统实践领域――如前面所述的领域，进入到新的【opportunity 机会、时机】的领域。）In addition, recent advances in the technology of data collection and processing have blurred the boundaries of practice and activity between what were previously regarded as related but separate areas. （另外，最近的数据采集和处理技术的发展模糊了以前被认为有联系却分离的领域的【实践的活动的practice and activity】界限）Such developments are forecast to continue and will create new career paths for graduates whose education and training is broadly based and of a high academic standard.（可以预见【forecast】，这种发展继续并将为涉猎广泛、学识一流的【broadly based and of a high academic standard】毕业生创造新的事业。）To enable graduates to take full advantage of these developments, significant changes in education and training are required.（为了使毕业生能充分利用【take full advantage of】这些发展，教育和训练的重大改革【significant changes】成为必需的）Academic and professional institutions are also responding, in part, by adopting the term geomatics both as a course and as an award title. （学院的和专业的机构也作出反应，部分地，采用术语“geomatics” 作为一门课程和一项授予资格【授予学位名称】）。A working definition of geomatics, which reflects current thinking and predicted change, is:（测绘学的一个现在使用的反映了当前的思想和对未来的预期的定义是：）The science and technology of acquiring, storing, processing, managing, analyzing and presenting geographically referenced information(geo-spatial data ).（获取、处理、存储，分析和上呈【presenting 呈现】地理参考信息（地理空间信息）的科学和技术。）This broad term applies both to science and technology, and mapping, geodesy, satellite positioning, photogrammetry, remote sensing, geographic information systems(GIS), land management ,computer systems, environmental visualization and computer graphics.（这个广泛的术语应用于科学和技术，以及制图、大地测量学、卫星定位、摄影测量学、遥感、地理信息系统、土地管理、计算机系统、环境可视化和计算机制图等领域）Several terms such as “geomatics” , “geomatic engineering,” and “geoinformatics” are now in common use pertaining to activities generally concerned with geographic information.（现在一些术语如“测绘学” ，“测绘工程” “地学信息学” 和共同应用于某些活动中―――专属于【pertain to】【generally】通常涉及【concern with】地理信息的活动。）These terms have been adopted primarily to represent the general approach that geographic information is collected, managed, and applied. （这些术语起初被采用用来表示地理信息的采集、管理和应用的总体的方法。）Along with

land surveying, photogrammetry, remote sensing, and cartography, GIS is an important component of geomatics. （连同土地测量学，摄影测量学，遥感和制图学一起，GIS 也是测绘学中重要的一个组成部分。）

Branches of Geomatics（测绘学分支）

Data acquisition techniques include field surveying, global positioning system(GPS), satellite positioning, and remotely sensed imagery obtained through aerial photography and satellite imagery. （数据获取技术包括普通野外测量，GPS 测量，卫星定位和遥感图像获取，通过航空摄影和卫星成像）It also includes the acquisition of database material scanned from older maps and plans and data collected by related agencies.（它还包括数据库资料的获取――通过扫描就有地图和设计图，还有有关机构收集的数据。）Data management and process are handled through the use of computer programs for engineering design, digital photogrammetry, image analysis, relational data base management, and geographic information systems (GIS).（通过计算机程序，数据管理和处理应用于工程设计，数字摄影测量【digital photogrammetry】，图像分析，相关资料库的管理和GIS。）Data plotting(presentation) is handled through the use of mapping and other illustrative computer programs; the presentations are displayed on computer screens(where interactive editing can occur) and are output on paper from digital plotting devices.（数据成图【数字成图】是通过制图和其他直观的计算机程序【illustrative 直观的、说明性的】进行的；其表达显示在计算机屏幕上（交互式编辑处理），也可以通过数字绘图仪输出到纸上。【handle 操作、处理】）Once the positions and attributes of geographic entities have been digitized and stored in computer memory, they are available for use by a wide variety of users.（一旦地理实体的位置和属性被数字化并被存储进计算机存储器，就可以有效的【available 有效的、可用的】为广泛的各种的使用者所用）Through the use of modern information technology(IT), geomatics brings together professionals in the following disciplines: surveying, mapping, remote sensing, land registration, civil and marine engineering, forestry, agriculture, planning and development, geology, geographical sciences, infrastructure management, navigation, environmental and natural resources monitoring, and computer science.（通过现代【估计moderm 应该是modern】信息技术，测绘学将以下学科的专业人员整合到一起：测量学、制图学、遥感、国土注册、土木【civil 民用的】工程和海洋工程，林业，农业，决策与发展，地质学，地理科学，基础设施【infrastructure】管理，导航，环境与自然资源监测和计算机科学。）Other Definitions of Geomatics （测绘学的其他定义）

As defined by the Canadian Institute of Geomatics in their quarterly journal “Geomatica”: Geomatics is a field of activities which, using a systemic approach, integrates all the means used to acquire and manage spatial data required as part of scientific, administrative, legal and technical operations【业务】involved in the process of the production and management of spatial information. （加拿大测量学会【Canadian Institute of Geomatics】在他们的季刊“地球空间信息学”中这样定义：测绘学是利用系统的方法，为生产和处理【management】科学的，行政的，法律的【legal】和技术的业务【operations】所需的空间信息，将所有获取和管理空间信息的方法【means】整合在一起的活动领域。【as part of 作为…… ）的一部分，这里不翻译出来】

The definition of Geomatics is evolving. A working definition might be “ the art, science and technologies related to the management of geographically-referenced information.” Geomatics includes a wide range of activities, from the acquisition and analysis of site-specific spatial data in engineering and development surveys to the application of GIS and remote sensing technologies in environmental management. It includes cadastral surveying, hydrographic surveying, and ocean mapping, and it plays an important role in land administration and land use management .（测绘学定义在发展。现

行的一个定义是“涉及工艺、科学和技术的地理信息的处理” 。测绘学或地球空间信息学包括一个广泛的生产活动――从工程学和发展了的测量学领域中特殊点的空间数据的获取和分析到GIS 和遥感技术在环境管理中的应用。它包括地籍测量、水道测量和海图测量，在土地管理和土地使用中扮演重要的角色。）Geomatics is the modern scientific term referring to the integrated approach of measurement, analysis, management, storage and display of the descriptions and location of Earthbased data, often termed spatial data. These data come from many sources, including earth orbiting satellites, air and sea-borne sensors and ground based instruments. It is processed and manipulated with state-of-the-art information technology using computer software and hardware. It has applications in all disciplines which depend on spatial data, including environmental studies, planning, engineering, navigation, geology and geophysics, oceanography, land development and land ownership and tourism. It is thus fundamental to all the geoscience disciplines which use spatially related data .（测绘学是一个现代科学术语，用以表示测量、分析、管理，存储和显示基于地球信息，经常被称为空间数据【often termed spatial data】数据的描述和位置的集成方法。这些数据来自各种数据源，包括地球轨道卫星，空载和舰载传感器及地面仪器。利用计算机软件和硬件，借助现代【state-of-the-art】信息技术。它的应用覆盖所有依赖空间数据的学科，包括环境研究，规划，工程学，导航，地质和地球物理学，海洋学，土地开发，土地经营和旅游学。它因而成为所有使用空间数据地球科学学科的基础。）[from the School of Geomatic Engineering, Univ. of New South Wales]（摘自新南威尔士大学测绘【或地球空间信息学】工程学院）

Geomatics is concerned with the measurement, representation, analysis, management, retrieval and display of spatial data concerning both the Earths physical features and the built environment. The principal disciplines embraced by Geomatics include the mapping sciences, land management, geographic information systems, environmental visualization, geodesy, photogrammetry, remote sensing and surveying. （测绘学是测量、表示，分析，处理，重获和显示关于地球物理特征和环境的空间数据的科学。其包括的主要学科有制图学，土地管理，GIS，环境可视化，大地测量学，摄影测量学，遥感和测量学。）[from the Dept. of Geomatics at Univ. of Melbourne]（摘自墨尔本大学测绘学系【或者地球空间信息学系】

Geomatics comprises the science, engineering, and art involved in collecting and managing geographically-referenced information. Geographical information plays an important role in activities such as environmental monitoring, management of land and marine resources, and real estate transactions. （测绘学包括自然科学，工程学和工艺或【技术】学；对地理信息的收集与管理。地理信息在环境监测，陆地和海洋资源管理，以及房地产交易【real estate 房地产，transaction 交易】中扮演重要角色。[from the Dept. of Geodesy and Geomatics Engineering at UNB]（摘自加拿大纽布朗斯维克大学测量与大地测量学系）

The science of Geomatics is concerned with the measurement, representation, analysis, management, retrieval and display of spatial information describing both the Earth’s physical fea tures and the built environment. Geomatics includes disciplines such as : Surveying, Geodesy, Remote Sensing & Photogrammetry, Cartography, Geographic Information Systems, Global Positioning Systems.（测绘学测量，表示，分析，管理，重获和显示空间信息，用来描述地球物理特征和环境。测绘学包括的学科有：测量学，大地测量学，遥感和摄影测量学，制图学，GIS，GPS ）[from the Dept. of Sruveying and Spatial Information Science at the Univ. of Tasmania] （摘自塔斯马尼亚大学，测量与空间信息科学系）

Unit 2 Geodetic Surveying and Plane Surveying（大地测量与平面测量）

Surveying has been traditionally defined as the art and science of determining the position of natural and artificial features on, above or below the earth’s surface; and representing this information in analog form as a contoured map, paper plan or chart, or as figures in report tables, or in digital form as a three dimensional mathematical model stored in the computer. （测量传统定义为确定地表、地下和地上的自然与人工地貌特征【features 形态、特征】；并使之按比例【in analog form】测绘成地形图【contoured map】、平面图【paper plan】或图表，或形成报告图表，或以数字形式形成三维立体数学模型存储进计算机。）As such, the surveyor/geodesist dealt with the physical and mathematical aspect of measurement. （同样的，测量员/大地测量学家处理的就是测量出的物理的和数学的特征）The accurate determination and monumentation【标石、标志】of points on the surface of the Earth is therefore seen as the major task. （因此精确确定并标定地表点位便成为测量的主要任务）Though these surveys are for various purposes, still the basic operations are the same---they involve measurements and computations or, basically, fieldwork and office work. （虽然测量工作有不同目的，基本的操作却都一样――他们包括测量和计算，或更基本地称之为，外业工作和内业工作）There are many different types of surveys such as land surveys, route surveys, city surveys, construction surveys,

hydrographic surveys, etc., but generally speaking, surveying is divided into two major categories: geodetic and plane surveying. （测量分为许多不同的类型，如土地测量，路线测量，城市测量，建筑测量，水道测量等等，但是总的来说，测量分为两个主要的种类：大地测量和平面测量）Surveys will either take into account the true shape of the Earth（Geodetic surveys）or treat the earth as a flat surface(Plane surveys). （是考虑地球真实形状的大地测量还是将地球当成一个平面的平面测量【紧跟着上句】）Additionally, surveys are conducted【表现】for the purpose of positioning features on the ground(Horizontal surveys), determining the elevation or heights of features(V ertical surveys) or a combination of both.（另外，测量还分为确定平面位置的水平测量和确定海拔的高程测量或两者的综合。）Geodetic Surveying（大地测量）

The type of surveying that takes into account the true shape of the earth is called geodetic surveying. （考虑地球真实形状的测量工作称为大地测量）This type of survey is suited for large areas and long lines and is used to find the precise location of basic points needed for establishing control for other surveys. （这种测量适用于大范围和长距离的测量工作，用来确立基本点的精确位置，用以建立其他测量工作所需的控制网。）In geodetic surveys, the stations are normally long distances apart, and more precise instruments and surveying methods are required for this type of surveying than for plane surveying.（在大地测量中，站点经常是互相距离很远，那么这种测量就比平面测量需要更精确的仪器和测量方法。）Widely spaced, permanent monuments serve as the basis for computing lengths and distances between relative positions. （广泛间隔开的永久标石就作为计算点位之间距离的基础）【serve 当作】These basic points with permanent monuments are called geodetic control survey points, which support the production of consistent and compatible data for surveying and mapping projects.（这种永久标石点被称为大地控制点，为测量和绘图工作提供可靠和一致的数据）In the past, ground-based theodolites, tapes【卷尺】, and electronic devices were the primary geodetic field measurements used. （过去，大地经纬仪【DJ 大地经纬仪的中文缩写】、卷尺和电子设备是大地测量的野外工作初时【primary】的工具。）Today, the technological expansion of GPS has made it possible to perform extremely accurate geodetic surveys at a fraction of the cost. （现在，技术的发展GPS 【expansion 扩充、膨胀】使大地测量工作花费非常小的代价【a fraction of 一小部分】就能获得极为精确的结果成为可能。）A thorough knowledge of the principles of geodesy is an absolute prerequisite for the proper planning and execution of geodetic surveys.（大地测量工作计划的编制【planning】和实施【execution】【proper 恰当的，翻译时略掉】，，绝对需要【absolute prerequisite】对大地测量学知识有全面的掌握。thorough knowledge of the principles 【A of geodesy is an absolute prerequisite 一个彻底的知识――大地测量学的原理的，是绝对需要的。）】In Geodetic Surveys, the shape of the earth is thought of as a spheroid, although in a technical sense, it is not really a spheroid. （在大地测量中，地球的形状被看成一个椭球体，虽然在技术角度来看，它不是真正的椭球。）Therefore, distances measured on or near the surface of the earth are not along straight lines or planes, but on a curved surface.（因此，在地球表面上或附近测量距离并不是沿着直线或平面进行，而是在一个曲面上。) Hence, in the computation of distances in geodetic surveys, allowances are made for the earth’s minor and major diameters from which a spheroid of reference is developed. （因此，在大地测量距离的计算中，参考椭球的长轴与短轴所带来的误差就显示【develop 显示出来】出来。）The position of each geodetic station is related to this spheroid. （每个大地站点的位置都与这个椭球有关）The positions are expressed as latitudes(angles north or south of the Equator) and longitudes(angles east or west of a prime meridian) or as northings and eastings on a rectangular grid.（这个位置是用纬度（与赤道面所成的角）和经度（与初子午线所成的角）或用在直角坐标系中的北距和东距来表示。）A geodetic survey establishes the fundamentals for the determination of the surface and gravity field of a country.

（大地测量为建立国家范围内的重力场和确定地表架构提供【establishes 建立】基础）This is realized by coordinates and gravity values of a sufficiently large number of control points, arranged in geodetic and gravimetric networks.（这将由测定布设在大地网和重力网中数量十分巨大的控制点，所得到的坐标和重力值来实现）In this fundamental work, curvature and the gravity field of the earth must be considered.（在这项基础工作中，地球的曲率和重力场都应被考虑。）Plane Surveying（平面测量）

The type of surveying in which the mean surface of the earth is considered a plane, or in which the curvature of the earth can be disregarded without significant error, generally is called plane surveying.（这种类型的测量把地球平均的表面视作平面，或认为地球曲率带来的误差可以忽略不计，这样的测量工作称为平面测量[significant 重大的，不翻译也行]）The term is used to designate survey work in which the distances or areas involved are of limited extent.（这个术语曾指涉及的距离及范围非常有限的测量工作【extent 范围】）With regard to horizontal distances and directions, a level line is considered mathematically straight, the direction of the plumb line is considered to be the same at all points within the limits of the survey, and all angles are considered to be plane angles.（由于被当成了水平距离和方向，水平线被当成直线【省略掉mathematically】，在这个有限范围内所有点上的铅垂线方向被认为是相同的，所有的角被认为都是平面角。）To make computations in plane surveying, you will use formulas of plane trigonometry, algebra, and analytical geometry. （在平面测量的计算中，你可以使用平面三角、代数、和平面解析几何的公式）For small areas, precise results may be obtained with plane surveying methods, but the accuracy and precision of such results will decrease as the area surveyed increases in size. （小范围内，平面测量方法可以获得精确的结果，但是随着范围的扩大，精度和准确度将随之下降）For example, the length of an arc 18.5 km long lying in the earth’s surface is only 7mm greater than the subtended chord and, further, the difference between the sum of the angles in a plane triangle and the sum of those in a spherical triangle is 2 only 0.51 second for a triangle at the earth’s surface having an area of 100km . （例如，地球表面一条18.5km 长的弧只比其所对的【subtend 与……相对】弦长7mm，further 【进一步，可以省略】，在一个面积为100 平方公里的平面三角形中的内角和与对应球面三角形中的内角和之差只有0.51 秒）It will be appreciated that the curvature of the earth must be taken into consideration only in precise surveys of large areas.（只有在大面积的精密测量工作中地球曲率才必需被考虑【appreciated 重视】）。A great number of surveys are of the plane surveying type.（多数的测量工作都是属于平面测量类型）Surveys for the location and construction of highways, railroads, canals, and in general, the surveys necessary for the works of human beings are plane surveys, as are the surveys made to establish boundaries, except state and national. （【特定】区域测量、公路【highway 是干道的意思，speedway、freeway 才是高速公路】建设、铁路、沟渠等，总的来说与人们工作密切相关的测量工作都是平面测量，不包括州界和国界测量在内的边界测量也同属平面测量）However, with the increasing size and sophistication of engineering and other scientific projects, surveyors who restrict their practice to plane surveying are severely limited in the types of surveys in which they can be engaged.（然而，随着工程和其他科学项目越来越大越来越复杂，在限定【restrict 约束】于从事平面测量工作的测量员在他们可以从事的测量类型上受到严格【severely 严格的】限制。【前面讲多数测量工作为平面测量，这里就转折的说从事平面测量的人员能进行的工作越来越少】）The operation of determining elevation usually is considered a division of plane surveying. （我们通常把高程的测量与平面测量分开来。）Elevations are referred to the geoid.（高程参考的是大地水准面。【或者说高程是相对于大地水准面而言的】）The geoid is theoretical only.（大地水准面只是在理论上存在）It is the natural extension of the mean sea level surface under the landmass. （它是平均海平面在大陆下的自然延伸。【它是平均海平面蔓延穿过大陆而成

的】）We could illustrate this idea by digging an imaginary trench across the country linking the Atlantic and Pacific oceans.（我们可以通过挖掘一个的想象中的连通大西洋和太平洋沟渠【trench】来阐明【illustrate】这个概念。）If we allowed the trench to fill with seawater, the surface of the water in the trench would represent he geoid. （如果我们允许这条沟渠注满海水，沟渠里的水面就代表大地水准面。）So for all intents and purposes, the geoid is the same as mean sea level. （因此，从所有的目的和用途出发，【直译：由于（为了？）所有的计划和目标】大地水准面与平均海平面是一样的。【for 引导原因】）Mean sea level is the average level of the ocean surface halfway between the highest and lowest levels recorded. （平均海平面是海水表面高度的记录值的平均值。【直译：平均海平面是指海水面的最高和最低记录之间纪录值的平均值。）】We use mean sea level as a datum or, curiously and incorrectly, a datum plane upon which we can reference or describe the heights of features on, above or below the ground.（我们用平均海平面作为一个数据，或不常用地和不准确地，当作一个基准面【datum plane】，通过它我们可以参考和描述地上、地表、地下的情况。）Imagine a true plane tangent to the surface of mean sea level at a given point. （想象一个真正的平面与平均海平面在一个特定【given 特定的、指定的】点上相切【tangent 正切的、相切的】）。At horizontal distances of 1km from the point of tangency, the vertical distances(or elevations) of the plane above the surface represented by mean sea level are 7.8cm. （在离切点1km 的地方，这个平面高于平均海平面的垂直距离为7.8cm。【represent by 通过……描述】）Obviously, curvature of the earth’s surface is a factor that cannot be neglected in obtaining even rough values of elevations. （很明显，即使在获取粗略的高程值的时候，地球表面曲率也是一个不可忽略的因素。）The ordinary procedure in determining elevations, such as【像这样、例如】balancing backsight and foresight distance in differential leveling, automatically takes into account the curvature of the earth and compensates for earth curvature and refraction, and elevations referred to the curved surface of reference are secured without extra effort by the surveyor.（常规的测高程的程序是，例如，在微差水准测量【differential leveling】中平衡前后视距【使前后视距相等】，地球曲率和大气折光影响将被自动考虑和低偿【compensate】，不必经测量者额外改正【effort 努力】，至参考曲面的高程就是可靠的了。）There is close cooperation between geodetic surveying and plane surveying.（大地测量和平面测量关系密切。）The geodetic survey adopts the parameters determined by measurements of the earth, and its own results are available to those who measure the earth. （大地测量采用通过测量地球得到的参数，而其计算结果又可以被测量地球【确定地球参数】的工作所利用【available 可利用的】）The plane surveys, in turn, are generally tied to the control points of the geodetic surveys and serve particularly in the development of national map series and in the formation of real estate cadastres.（接下来【in turn】，平面测量，一般依赖于大地测量建立的控制点，在国家地图系列【国家地图集】的发展和在房地产地籍【real estate cadastre】信息领域提供特别服务。）

Unit 3 Distance Measurement（距离测量）

One of the fundamentals of surveying is the need to measure distance.（测量工作的一项基础【fundamental 基本原则，同时有基础的意思】是距离测量）（距离不一定指的是直Distances are not necessarily linear, especially if they occur on the spherical earth. 线的，尤其是在地球曲面上的距离）In this subject we will deal with distances in Euclidean space, which we can consider a straight line from one point or feature to another. （这里【In this subject 翻译成这里】，我们所涉及的是欧几里德空间，我们可以认为一条从一点到另一点或一个特征到另一个特征的线是直线。）斜距、Distance between two points can be horizontal, slope, or vertical. （两点之间的距离可以是平距、或者是垂距。）Horizontal and slope distances can be measured with lots of techniques of measurement depending on the desired quality of the result. （根据测量结果的精度【quality 质量】要求不同，平距或斜距有多种测量方法）If the points are at different elevations, then the distance is the horizontal length between plumb lines at the points. （如果这些点在不同高程上，那么平距指的是过点的垂线【plumb lines】之间的水平长度。）Here gives a brief summary of relevant techniques and their respective accuracies: （这里给出一个简短的相关【relevant 相关的】技术的摘要【summary 摘要】和它们各自的【respective 各自的】精度）

Pacing and Odometer（步测和自动计程仪）

Pacing is a very useful form of measurement though it is not precise, especially when surveyors are looking for survey marks in the field.（虽然不精确，但步测是一个非常有用的测量方法【form of measurement】，尤其是测量者在野外寻找测量标志时。）Pacing can be performed at an accuracy level of 1/100~1/500 when performed on horizontal land, while the accuracy of pacing can’t be relied upon when pacing up or down steep hills.（当在水平场地进行时，步测可以达到1/100 到1/500 的相对精度，而当地面起伏较大时，这样的精度就不能保证了。）The odometer is a simple device that can be attached to any vehicle and directly registers the number of revolutions of a wheel.（自动计程仪是一个简单的装置，可以附属于【be attached to 附属于】车辆之上并直接记录【register 记录v.】轮子的旋转周数。）With the circumference of the wheel known, the relation between revolutions and distance is fixed. （由于知道了轮子的周长【circumference of the wheel 轮周】，转数【revolution 这里有转数的意思】和距离之间的关系就确定下来【fix 确定】）。

Ordinary Taping and Precise Taping（普通尺距测量和精密尺距测量）

Taping is a very common technique for measuring horizontal distance between two points.（尺距测量是测量两点之间平距的非常普遍的方法。）Ordinary taping refers to the very common tapes that we can buy them in stores, such as the plastic tapes or poly tapes. 普通尺距测量使用（【refers to 引用】的是我们可以在商店里买到的非常普遍的的尺子，例如塑胶尺或涤纶尺。）Such tapes have low precision in distance measurements with about 1/3000~1/5000.（这种尺的精度低，测距精度只有1/3000 到1/5000）The precise taping refers to the steel tapes and which are much more expensive than the plastic tape and have higher precision of 1/10000~1/30000.（精密尺距测量使用的是比塑胶尺贵的多的钢尺，并具有更高的精度――1/10000 到1/30000）Invar tapes are composed 35% nickel and 65% steel.（因瓦尺是由35％的镍和65％的钢组成）This alloy has a very low coefficient of thermal expansion, making the tapes useful in precise distance measurement. （这种合金具有非常低的热膨胀【thermal expansion】系数【coefficient】，使得这种尺利于精密距离测量）Many tapes are now graduated with foot units on one side and metric units on the reverse side. 现在许多（尺上都在正面标刻【graduate 标刻、刻】了英尺计量单位，而在反面标刻了米制计量单位）Metric units are in meters, centimeter and minimeter with the total length of 20 m, 30 m, 50 m and 100 m. （米制计量单位是米，厘米和毫米，尺的总长为20m、30m、50m 或100m）If we want to measure the horizontal distance between the two points A and B, we can do like this: （如果我们想测量A 点和B 点之间的平距，我们可以这样来做：）With zero of the tape to the higher point B and tape going along the point A, we can measure the horizontal distance by using the plumb bob with pump line entering to the point A.（将尺的0 刻度对准较高点B 点，尺沿向A 点，我们可以利用在A 点的铅垂【plumb bob】垂线【pump line 应为plumb line 垂线】测出平距）To judge the exact horizontal line, we should move the tape up and down along the pump line and we will find the changes of reading in the tape.（为了确定准确的水平线，我们应沿垂线方向上下移动尺子，我们在尺上将得到不同的的读数【changes of reading 读数的变化】）The shortest reading of the tape is the horizontal distance.（尺子最小的读数就是平距）If the distance is longer than the length of tape, then we can divide the long distance into several segments and get the total distance by plus each segment together.（如果距离比尺长要长，那么【then】我们可以将其分成几段【segment】，把每段长加起来获得总长。）Since different tapes have different starts of zero of the tapes, it is very important to judge where the zero of the tape begins.（由于不同的尺有不同的0 刻度，判断尺的0 刻度在哪儿十分重要。）

Tacheometry and Stadia （视距测量和视距仪）

Tacheometry is an optical solution to the measurement of distance.（视距测量是一个光学【optical】测距方法）The word is derived from the Greek Tacns, meaning “swift”, and metrot, meaning “a measure”.（这个词源自于【is derived from 源自于】希腊语的Tacns，意思是“迅速的” ，和metrot【同样是希腊语】，意思是“方法”）。Tacheometry involves the measurement of a related distance parameter【参数】either by means of a fixed-angle intercept.（视距测量包括一个相关距离参数的测量和依靠定角截距的测量【by means of 依靠】【either 表示并列】）Theodolite tacheometry is an example of stadia system. （经纬仪视距测量就是视距仪器的一个例子）The theodolite is directed at the level staff where the staff is held vertically and the line of sight of the telescope is horizontal.（将经纬仪【is directed at 被动语态，翻译为将；direct at 对准……】对准水准尺【level staff】，水准尺竖直，望远镜的视线【可以翻译为视准轴】水平。）By reading the top and bottom stadia hairs on the telescope view and then the horizontal distance from center of instrument to rod can be obtained by multiplying the stadia interval factor K by the stadia interval and plus the distance C which is from the center of instrument to principal focus, i.e. D=Ks + C. （通过望远镜视野【view】里的上下视距丝读数，从仪器到尺的平距可以用视距常数【stadia interval factor】K 乘视距间隔【stadia interval】加上从

仪器中心到主焦点【principal focus】的距离C 得到。也就是【i.e.拉丁文？】，D=Ks + C）Usually the nominal stadia interval factor K equals 100 which is a constant for a particular instrument as long as conditions remain unchanged, but it may be determined by observation in practice.（通常，名义上的视距常数K 等于100，【as long as】只要条件保持不变，它就是个特别装置的【particular instrument 指代视距装置】常数【constant 常数】但在实践中可以通过观测确定）The value of C is determined by the manufacturer and stated on the inside of the instrument box.（C 值由厂商决定并固定在仪器之内）For external-focusing telescopes, under ordinary condition, C may be considered as 1 ft without error of consequence.（对于外调焦望远镜，通常情况下，C 被认为是1 英尺而不会给结果带来错误。）Internal-focusing telescopes are so constructed that C is 0 or nearly so; this is an advantage of internal-focus telescopes for stadia work.（内调焦望远镜因此被发明【construct 建立、创立】为或，C 近似为0；这是内调焦望远镜在视距测量中的一个优点。）Most instruments now used for stadia are equipped with internal-focusing telescopes.（现在大多数视距仪器都使用内调焦望远镜）Applications of tacheometry include traversing and leveling for the topographic surveys, location of detail surveys, leveling and field completion surveys for the topographic mapping, and hydrographic mapping. （视距测量的应用包括地形测量【topographic survey】中的导线测量【traversing】和水准测量【leveling】工作，细部测量【detail survey】中的定位，绘制地形图工作中的水准测量和野外完全化测量，以及水道测图）The relative precision is 1:1000 to 1:5000.（其相对精度为1:1000 到1:5000）Stadia is a form of tacheometry that uses a telescopic cross-hair configuration to assist in determining distances.（视距仪是视距测量的一种形式，利用望远镜的十字丝结构帮助测距）A series of rod readings is taken with a theodolite and the resultant intervals are used to determine distances. （一系列的标尺读数由经纬仪测出，并且籍此而得到视距间隔，用来确定距离【resultant 由此产生的】）

Electronic Distance Measurement(EDM) （电子测距仪）

The Electronic Distance Measurement(EDM) was first introduced in 1950s by the founders of Geodimeter Inc.（电子测距仪的概念是由Geodimeter【“光电测距仪”――商标名】公司的创始人在20 世纪50 年代引入的。）The advent of EDM instrument has completely revolutionized all surveying procedures, resulting in a change of emphasis and techniques.（EDM 测量手段的出现【advent】是对所有测量手段的完全的革命【revolutionized 革命化的】导致，【result in】了一场技术革命【change】和侧重点的改变。【emphasis 侧重点】）Distance can now be measured easily, quickly and with great accuracy, regardless of terrain conditions. （现在距离可以被很容易、快速和精确的测量，而又不受地形【terrain】影响。）EDM instruments refer to the distance measurement equipments using light and radio waves. （EDM 是利用光波和无线电波测距的设备【refer to 译为“是”）】Both light waves and radio waves are electromagnetic.（光波和无线电波都是电磁波【electromagnetic 电磁的】）They have identical velocities in a vacuum (or space) to 299,792.458±0.001km/sec. （它们在真空中都有一样的速度299,792.458±0.001km/sec）These velocities, which are affected by the air’s density, are reduced and need to be recalculated in the atmosphere. （它们的速度，由于会收到空气密度的影响而降低，在大气中需要重新计算【recalculate】）The basic principle of EDM instruments is that distance equals time multiplied by velocity. （EDM 的基本原理是距离等于时间乘速度）Thus if the velocity of a radio or light wave and time required for it to go from one point to another are known, the distance between the two points can be calculated.（这样，如果无线电波或光波的速度和其从一点到另一点所需的时间已知了，两点之间的距离就可以计算出来）The EDM instruments may be classified according to the type and wavelength of the electromagnetic energy generated or according to their operational range.（可以依照产生【generate】的电磁能量【电磁波】的类型和波长或根据它们的运作范围【工作范围】给EDM 分类。）EDM instruments use three different wavelength bands:

(1)Microwave systems with range up to 150km, wave length 3 cm, not limited to line of sight and unaffected by visibility;

(2)Light wave systems with range up to 5 km (for small machines), visible light, lasers and distance reduced by visibility;

(3)Infrared systems with range up to 3 km, limited to line of sight and limited by rain, fog, other airborne particles. （EDM 使用三种不同波长的波段：(1)微波系统【波段】，其测距范围达150km，波长3cm，不受限于视线范围，也不受可见度的影响；(2)可见光波段，有效范围5km（小型仪器），可见光、激光，其距离受可见度的影响会降低；

(3)红外线【Infrared】波段，测程3km，受限于视线范围，并且受限于空气中的微粒影响）Although there is a wide variety of EDM instruments available with different wavelengths, there are basically only two methods of measurement employed which may divide the instruments into two classification as electro-optical (light waves) and microwaves (radio waves) instruments.（尽管不同的EDM 用到不同的波长，基本上只有两种测量方法在使用，可以将其【即EDM】分为光电测距仪和微波测距仪）These two basic methods are namely the pulse method and more popular phase different method. 这两种（基本方法即【namely 即】脉冲【pulse】法和更流行的相位【phase different 相位的不同】法）They function by sending light waves or microwaves along the path to be measured and measuring the time differences between transmitted and received signals, or in measuring the phase differences between transmitted and received signals in returning the reflecting light wave to source. （沿着要测的路径发射光波或微波，并测出发射和收到反射信号之间的时间间隔，或者是测出发射和接受反射信号之间的相差【phase differences】，它们通过这种方法来运行【function v.】）Modern EDM instruments are fully automatic to such an extent that, after the instruments, set up on one station, emits a modulated light beam to a passive reflector set up on the other end of the line to be measured.（现代的EDM 全自动化到这样的程度【to such an extent that 到这样的程度】，在一个站点安置，需测距离线的另一处安置有反射棱镜，发射一束已调制【modulated 已调制的】的光束到棱镜上）The operator need only depress a button, and the slope distance is automatically displayed. （操作者仅仅需要按一个键，斜距就自动显示出来。）More complete EDM instruments also have the capability of measuring horizontal and vertical or zenith angles as well as the slope distance. （更完全的【功能更完备的】EDM 还具有测水平角、竖直角和天顶角的功能）These instruments referred to as total station instruments. （这种仪器被称为全站仪）

Unit 4 Angle and Direction Measurement（角度和方向测量）

Horizontal and vertical angles are fundamental measurements in surveying.（水平角和竖直角是测量的基本测量工作）It is necessary to be familiar with the meanings of certain basic terms before describing angle and direction measurement.（在描述角度和方向测量之前，有必要熟悉【be familiar with 熟悉】几个【certain 某些】基本术语的含义【meaning】）The terms discussed here have reference to the actual figure of the earth.（这里讨论的这些术语与地球的真实形状有关【have reference to 与……有关】）

Basic Terms（基本术语）

A vertical line at any point on the earth’s surface is the line that follows the direction of gravity at that point.（地球表面任一点的垂线是指这点上沿着重力的方向的线【可译为：地球表面任一点的垂线方向是过该点的重力方向】）It is the direction that a string will assume if a weight is attached at that point and the string is suspended freely at the point. （如果在这点上用线悬挂一个重物，当线自由【即无干扰】静止【suspended 暂停的、悬浮的】时，这条线所呈现【assume 呈现】的方向即重力方向。）At a given point there is only one vertical line.（在给定的一个点上只有一条垂线。）

A horizontal line at a point is any line that is perpendicular to the vertical line at the point. （一点上的水平线是垂直【perpendicular 垂直的】于过该点的垂线的直线。）At any point there are an unlimited number of horizontal lines.（过任一点的水平线有无数【unlimited】条。）

A horizontal plane at a point is the plane that is perpendicular to the vertical line at the point. （过一点的水平面是垂直于过该点的垂线的平面）There is only one horizontal plane through a given point.（过给定的一个点只有一个水平面）

A vertical plane at a point is any plane that contains the vertical line at the point.（过一点的竖直面是包含【contain】过该点的垂线的任一平面）There are an unlimited number of vertical planes at a given point.（过给定的一点有无数个竖直面）

Horizontal Angle and Vertical Angle（水平角和竖直角）

A horizontal angle is the angle formed in a horizontal plane by two intersecting vertical planes, or a horizontal angle between two lines is the angle between the projections of the lines onto a horizontal plane.（水平角是指在一个水平面内由两相交【intersect 相交v.】的竖直面形成的角，或者说，两条线之间的水平角是这两条线在水平面上的投影线的夹角）For example, observations to different elevation points

B and

C from A will give the horizontal angle ∠bac which is the angle between the projections of two lines (AB and AC) onto the horizontal plane. （例如，在A 点观测不同高度的 B 和 C 点，其水平角∠bac 是由AB 和AC 两条线在水平面上的投影构成的）It follows that, although the points observed are at different elevations, it is always the horizontal angle and not the space angle that is measured (Figure 1).（由此得出结论【It follows that 由此得出结论】，虽然被观测的点在不同的高度上，测出的总是水平角而不是空间角。）The horizontal angle is used primarily to obtain relative direction to a survey control point, or topographic detail points, or to points to be set out.（水平角主要【primarily】用来由联测控制点获得相对方向，或者地形测量碎

部点、或者放样点【or to points to be set out 应该是or points to be set out 才对吧？？？direction to a survey control point、topographic detail points、points to be set out 并列都是obtain 的宾语。）】A vertical angle is an angle measured in a vertical plane which is referenced to a horizontal line by plus (up) or minus (down) angles, or to a vertical line from the zenith direction.（竖直角是在一个竖直面内参考于【reference 参考】水平线的正（仰）角或负（俯）角，或者相对于一个天顶方向的垂线的角）Plus and minus vertical angles are sometimes referred to as elevation or depression angles, respectively. （正负竖直角有时分别【respectively 分别地】被称为仰角【elevation angle】或俯角【depression angle】）A vertical angle thus lies between 0° and ±90°.（竖直角位于【lie 位于】0～90 度之间）Zenith is the term describing points on a celestial sphere that is a sphere of infinitely large radius with its center at the center of the earth.（天顶方向是一个术语，用来描述在天球【celestial sphere 天球】上的点，天球是一个半径无限【infinitely 无限地】大的球，其中心在地球中心。）The zenith is an angle measured in a vertical plane downward from an upward directed vertical line through the instrument.（天顶距是一个在竖直面内从一个过仪器的被定向为向上的竖直方向线向下测量的角。）It is thus between 0°and 180°.（它的范围是从0 到180 度）Obviously the zenith angle is equal to 90°minus the vertical angles.（显然，天顶距等于90 度减去竖直角）Vertical angles or zeniths are used in the correction of slope distance to the horizontal or in height determined.（竖直角或天顶距用于斜距化平距的改正或者高程的测量）For the most part, the instrument used in the measurement of angles is called a transit or theodolite, although angles can be measured with clinometers, sextants (hydrographic surveys), or compasses. （在极大程度上【for the most part】，用来测角的工具被称为经纬仪，虽然角度可以用倾斜仪【一种测量物体随时间的倾斜变化和铅垂线随时间变化的仪器】、六分仪（用于海道测量）、或罗盘仪来测）The theodolite contains a horizontal and vertical circles of either glass or silver.（经纬仪有一个玻璃的或镀银的水平度盘和竖直度盘）The horizontal and vertical circles of theodolite can be linked to circular protractors graduated from 0° to 360° in a clockwise manner set in horizontal and vertical plane.（经纬仪的水平度盘和竖直度盘与顺时针刻【graduate】了0 到360 度刻划的圆分度器【circular protractor】相连）The horizontal circle is used when measuring or laying off horizontal angles and the vertical circle is used to measure or lay off vertical angles or zenith angles.（测或拨水平角时用水平度盘，测或拨竖直角或天顶距时用竖直度盘【lay off 翻译为拨、放样的意思】）Usually the units of angular measurement employed in practice are degrees, minutes, and seconds, the sexagesimal system. 通常角度测量法（【angular measurement 角度测量法】使用的单位是六十进制【sexagesimal 六十进制的】的度、分、秒）

Angle Measurement （角度测量）

A horizontal angle in surveying has a direction or sense; that is, it is measured or designed to the right or to the left, or it is considered clockwise or counterclockwise. （在测的水平角有方向【direction、sense 这里都是方向方向的意思】，就是说【that is】它是向左测还是向右测，或者是说，顺时针测还是逆时针测）方向In the above figure, the angle at A from

B to

C is clockwise and the angle from C to B is counterclockwise. （如上图所示，在A 点由B 到C 就是顺时针角，而从C 到B 就是逆时针角）With the theodolite set up, centered, and leveled over at station A, then a simple horizontal angle measurement between surveying point B, A and C would be taken as follows:（经纬仪在A 点安置、对中、整平后，在B、A 和C 测量点间的简单的水平角测量可以按下列步骤进行：）

⑴Commencing on, say, “face left”, the target set at survey point B is carefully bisected and the reading on horizontal scale is 25°.（着手，说【示意】“盘左”【用竖丝】将B 点的目标仔细分中，水平，，度盘读数为25 度）

⑵The upper plate clamp is released and telescope is turned clockwise to survey point C. The reading on horizontal

circle is 75°（水平度盘制动螺旋松开，顺时针转动望远镜至C 点，水平度盘读数75 度）

⑶The horizontal angle is then the difference of the two directions, i.e. (75°-25°) =50°（水平角就是两个方向值的差值，即，(75°-25°) =50°）

⑷Change face and observe point C on “face right”, and note the reading=255°（换度盘方向至盘右并照准C 点，记下读数为255 度）

⑸Release upper plate and swing counterclockwise to point B and note the reading =205°（松开水平度盘，逆时针旋转【swing】至B 点并记下读数为205 度）

⑹The reading or the direction must be subtracted in the same order as 255°-205°=50°（读数或者说是方向值按同样的法则【order】相减，255°-205°=50°）

⑺The mean of two values would be accepted if they are in acceptable agreement.（如果两个减出来的值的一致性是可接受的【在误差范围之内】，取两个值的平均值。）Modern electronic digital theodolites contain circular encoders that sense the rotations of the spindles and the telescope, convert these rotations into horizontal and vertical (or zenith) angles electronically, and display the value of the angles on liquid crystal displays (LCDs) or light-emitting diode displays (LEDs).（现代的电子数字经纬仪包含编码【encoder 编码】度盘，能够感知轴【spindle 轴、纺锤】和望远镜的旋转，并使之电子地转换为水平角度和竖直角度，并在液晶显示器【LCDs】或发光二极管显示器【LEDs】上显示出来）These readouts can be recorded in a conventional field book or can be stored in a data collector for future printout or computation.（这些显示可以被一个传统的【conventional】野外电子手簿或数据收集器【存储卡】记录，以便日后打印或计算）The instrument contains a pendulum compensator or some other provision for indexing the vertical circle readings to an absolute vertical direction. （这种仪器具有一个悬挂【pendulum 钟摆】补偿器【compensator】或其它装置，使竖盘指标【indexing 指标】读数指向一个绝对竖直方向）The circle can be set to zero readings by a simple press of a button or initialized to any value on the instrument.（这个度盘可以通过简单的按一个键就将其置零，或初始化成任一值）

Azimuth is the horizontal angle measured in a clockwise direction from the plane of the meridian, which is a line on the mean surface of the earth joining the north and south poles. （方位角是从子午面【plane of the meridian 】起算按顺时针旋转的角，子午线是在地球平均表面连接北极与南极的线）Azimuth ranges in magnitude from 0° to 360° , values in excess of 360° , which are sometimes encountered in computations, are simply reduced by 360° before final listing.（方位角的取值范围从0 度到360 度，超过360 的值――有时会在计算时遇到【encounter 遭遇】，只需减去360 度即可）

Bearing is the traditional way of stating the orientation of the line.（方向角是一种传统的描述【state 说明】直线方向【orientation 方向、方位】的方法）It is actually the angle measured from the north or south.（实际上，它是从南或北方向开始量测的角）The bearing, which can be measured clockwise or counterclockwise from the north or south end of the meridian, is always accompanied by letters that locate the quadrant in which the line falls.（方向角可以从子午线【meridian】北端或南端以顺时针或逆时针量测，总是伴【accompany】以字母，用来标明【locate 定位】直线所落在的象限【quadrant】）For example, bearing N32W indicates a line trending 32° west of the north. （例如：方向角N32W 代表【indicate】一条直线从北方向转向【trend 通向、转向】西方向32 度）It is equal to an azimuth of 328°.（它等于方位角328 度）Bearing S12W indicates a line trending 12° west of the south. （方向角S12W 代表一条直线从南方向转向西方向12 度）It is equal to an azimuth of 192°.（它等于方位角192 度）It is important to state that the bearing and azimuth are respect to true north.（需要重点说明的是，方向角和方位角所用的【respect 关于、

有关、尊重】是真北方向。

Unit 5 Traversing （导线测量）

The purpose of the surveying is to locate the positions of points on or near the surface of the earth. （测量的目的是确定地表或接近地表的点的点位。）To determine horizontal positions of arbitrary points on the earth’s surface and elevation of points above or below a reference surface are known as a control survey.（确定地表任一【arbitrary 任意的】点的平面位置和确定点高于或低于一个参考面的高程的工作被称为控制测量）The positions and elevations of the

points make up a control network.（这些点的平面位置和高程组成了一个控制网）There are different types of control networks depending on where and why they are established.（依照它们建立的地点和目的不同，有不同的控制网类型）

A control network may have very accurate positions but no elevations (called a Horizontal Control Network) or very accurate elevations but no positions (called a Vertical Control Network).（一个控制网可能有精确的平面位置而没有高程（称为平面控制网），或者有精确的高程而没有平面位置（称为高程控制网））Some points in a control network have both accurate positions and elevations.（有些控制网的点既有精确的平面位置也有精确的高程）Control networks range from small, simple and inexpensive to large and complex and very expensive to establish.（控制网的范围从小的、简单的、便宜的网到大的、复杂的、昂贵的网）A control network may cover a small area by using a “local” coordinate system that allows you to position the features in relation to the control network but doesn’t tell you where the features are on the surface of the earth, or cover a large area by consisting of a few well-placed and precise-established control points, which is sometimes called the primary control.（一个控制网可以是覆盖小范围，使用区域坐标系统，允许你相对于控制网确定地貌特征【feature】，但却不告诉你它们在地表的什么地方；或者覆盖一个广大区域，由少数被适当安置并精确测设的控制点组成，有时被称为基础控制）The horizontal positions of points in a network can be obtained in a number of different ways.（控制网的点的平面位置可以由许多不同方法来获得）The generally used methods are triangulation, trilateration, traversing, intersection, resection and GPS.（一般使用的方法有，三角测量、三边测量、导线测量、交会测量、后方交会测量、和GPS 测量）The main topic of this text refers to the traversing.（这篇课文主要讲的是导线测量）

Triangulation（三角测量）

The method of surveying called triangulation is based on the trigonometric proposition that if one side and three angles of a triangle are known, the remaining sides can be computed by the law of sines. （这种测量方法称为三角测量，基于三角【trigonometric 三角法的】法则【proposition 命题】【that 引导的，宾语从句】如果三角形的一条边和三个角已知，剩下的边可以用正弦定理【law of sines】计算出）Furthermore, if the direction of one side is known, the direction of the remaining sides can be determined.（而且，如果一条边的方向已知，余下的边的方向也可以确定）And then coordinates of unknown points can be computed by application of trigonometry.（那么未知点的坐标就可以使用三角法计算出来）

Trilateration（三边测量）

Since the advent of long-range EDM instrument, a method of surveying called trilateration was adopted to combine with triangulation.（自从远距EDM 出现【advent 出现】以来，一种叫做三边测量的方法用来和三角测量联合使用。）The trilateration is based on the trigonometric proposition that if the three sides of a triangle are known, the three angles can be computed by the law of cosines.（三边测量基于三角法则——如果三角形的三条边已知，那么三个角可以由余弦定理【law of cosines】计算出）Trilateration possesses some advantages over triangulation because the measurement of the distances with EDM instrument is so quick, precise and economical while the measurement of the angles needed for triangulation may be more difficult and expensive.（三边测量具有【possess 拥有、具有】一些相对于三角测量的优势，EDM 测距快速、准确、经济，而三角测量所需的角度测量则相对困难和昂贵）For some precise projects, the combination of triangulation and trilateration which is called triangulateration is applied.（在一些精密工程当中，三角测量和三边测量联合使用，被称为边角测量）

Traversing（导线测量）

A survey traverse is a sequence of lengths and directions of lines between points on the earth, obtained by or from field angle and distance measurements and used in determining positions of the point. （【测量工作中的】导线是一系列【sequence 次序、系列】地球上点之间的有长度和方向的直线，【导线】由野外角度和距离测量获得，用来确定点位）The angles are measured using transits, theodolites, or total stations, whereas the distances can be measured using steel tapes or EDM instruments.（角度可以使用经纬仪或全站仪来测，而【whereas】距离可以使用卷尺或EDM 来测）A survey traverse may determine the relative positions of the points that if connects in series, and if tied to control stations based on some coordinate system, the positions may be referred to that system.（导线可以用来确定互相连接点的相对位置【relative position】，如果想控制某些坐标系中的站点【以某坐标系的点为站点】，其【指stations】位置应参考该坐标系）From these computed relative positions, additional data can be measured for layout of new features, such as buildings and roads.（从这些计算出的相对位置，另外的数据可以量出来，用以放样【layout】新的地物【features 特征，理解为地物】，如：建筑物和道路。）Since the advent of EDM equipment, traversing has emerged as the most popular method to establish control networks such as basic area control, mapping, control of hydrographic surveys and construction projects. （自从EDM 的出现【advent】，导线测量作为最常用的建立控制网的方法显现【emerge 显现】出来，例如基础区域控制、图根控制、水道测量控制和建筑工程控制【建筑施工控制】）In engineering surveying, it is ideal way to surveys and dimensional control of route-type projects such as highway, railroad, and pipeline construction. （在工程测量当中，导线测量是线型工程测量和立体【dimensional 空间的】控制的理想方法，线型工程例如公路、铁路、和管线建筑）In general, a traverse is always classified as either an open traverse or a closed traverse.（总体上【In general】，导线总是分为支导线和闭路导线【按说open traverse 是支导线，closed traverse 是闭合导线，而connecting traverse 是附合导线】）An open traverse originates either at a point of known horizontal position with respect to a horizontal datum or at an assumed horizontal position, and terminates at a station whose relative position is not previously known.（支导线起始于【originate 起源】一个水平位置已知（相对于一个水平基准【水平坐标系】）或水平位置假定的点，终止【terminate】于相对位置【relative position】事先未知的站点。）The open traverse provides no check against mistakes and large errors for its termination at an unknown horizontal position and lack of geometric closure.（由于其终点位置未知并且缺乏图形闭合【geometric 几何的】【closure 闭合n.】，支导线不能提供对错误和较大误差的检核）This lack of geometric closure means that there is no geometric verification possible with respect to the actual positioning of the traverse stations.（这种图形闭合的缺少意味着没有几何上的检核【verification 检核】可能性【possible 可能性n.】，对于实际的导线点的确定。【对于实际导线点的测量来说，这种图形闭合的缺少意味着没有几何检核条件】）Thus, the measuring technique must be refined to provide for field verification.（因而，这种测量技术应当提供野外的检核使之精确【refine 精炼】）。【字面的意思是该技术应当被精确化提供给野外确认【verification 确认、核实】】At a minimum, distances are measured twice and angles are doubled.（至少【minimum 最小值】，距离测两遍，角度测两个测回。）Open traverses are often used for preliminary survey for a road or railroad.（支导线经常用于道路或铁路的初测【preliminary survey】）A closed traverse can be described in any one of the following two ways:（闭路导线可以由下面两种方式的任一种描述：）⑴A closed loop traverse, as the name implies, forms a continuous loop, enclosing an area. （闭合环路导线，正如名字所示，呈一个连续的环，围绕【enclose】一个区域）This type of closed traverse starts at assumed horizontal position or at a known horizontal position with respect to a horizontal datum and ends at the same point.（这种闭路导线起始于一个平面位置假设或相对于一个水

平基准【坐标系统】已知的点，并终止于该点）⑵A connecting traverse starts and ends at separate points, whose relative positions have been determined by a survey of equal or higher order accuracy.（附合导线起始和终止于不同【separate】的点，它们【起点与终点】由等于或高于规定精度的测量测设）A known horizontal position is defined by its geographic latitude and longitude, or by its X and Y coordinates on a grid system.（一个已知的水平位置是由它的大地经纬度【geographic latitude 大地纬度；geographic longitude 大地精度】或格网系的X Y 坐标表示【define】）Closed traverses, whether they return to the starting point or not, provide checks on the measured angles and distances.（闭合导线，无论它们是否回到起始点，都能提供角度和距离检核。）In both cases, the angles can be closed geometrically, and the position closure can be determined mathematically.（在两种情况中，角度可以在几何上闭合，位置闭合可以数学的确定【计算出来】）Therefore they are more desirable and used extensively in control, construction, property, and topographic surveys. （因此它们更理想【desirable 理想的】，在控制测量、建筑测量、房地产测量和地形测量使用更广泛）As we mentioned above, a closed traverse provides checks on the measured angles and distances.（正如我们上面所提到的【如上所述】，闭合导线可以提供角度和距离的检核）For example, the geometric sum of the interior angles in an n-side closed figure should be (n-2) ×180°, but due to systematic and random errors of the measurements, when all the interior angles of a closed traverse are summed, they may or may not total the number of degrees required for geometric closure.（例如，在一个n 边闭合图形当中，内角【interior angle】和【geometric 几何的可不翻译】应该是：(n-2)×180°，但是由于【due to】测量中系统误差和偶然误差的存在，当闭合导线所有的内角加起来后，其角度和【total】可能等于或不等于其几何理论闭合差值）The difference between the geometric sum and actual field sum of the interior angles is called angular closure. （内角和的理论值【geometric 几何的】和实际值的差值被称为角度闭合差【angular 关于角的】【closure 闭合度】）The total error of angular closure should be distributed evenly to each angle (if all angles were measured with the same precision) before mathematical analysis of the traverse.（在导线进行数学分析【即导线计算】之前，角度闭合差应该平均【evenly 平均地】分配【distribute 分配】到每个角上（如果所有的角都是相同观测精度））The important point before doing this is that the overall angular closure can’t be beyond the survey specifications.（重要的一点是，在这样做【指上句话那样做】之前，所有的闭合差都不得超过测量规范【specification 规范】）Closed traverses provide also checks on the measured distances, and the position closure can be determined mathematically, which means that an indication of the consistency of measuring distances as well as angles should be given to a traverse that closes on itself.（闭合导线同时提供测量过的距离的检核，位置的闭合差可以计算得到，这就意味着测量的距离同测角一样，应当予以闭合【像上面角度那样traverse 为什么不翻译？？】【consistency 一致性】【indication 指出、迹象】【which 引导非限定性定语从）句】Theoretically this position closure from the origin back to itself should be zero. （理论上【Theoretically】，从起点闭合到它自己，位置的闭合差应该是0）But the Errors in the measured distances and angles of the traverses, however, will tend to alter the shape of the traverse, therefore we should compute the algebraic sum of the latitudes and algebraic sum of the departures, and compare them with the fixed latitude and departure of a straight line from the origin to the closing point.（但是距离和角度的测量误差，会【tend to 趋向】改变【alter】导线的形状，因此我们应当分别计算纵距【latitude 纬度、纵距】与横距【departure】的代数【algebraic 代数的】和，然后与从起点到终点的连线的确定的【fixed】纵距与横距相比较）By definition, latitude here is the north/south rectangular component of a line and departure is the east/west rectangular component of a line.（精确的说【definition 定义】，这里的纵距【latitude 纬度、纵距】就是指一条直线的直角坐标的【rectangular 矩形的、直接坐标的】南北分量【component 分量】，横距【departure】就是指一条直线的直角坐标的东西分量）To differentiate direction, north is considered plus, whereas south is considered minus. （对于不同的方向来说，北方向为