测绘工程专业英语全文翻译

Uuit1 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 –MA TICS 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 science- and/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，一般【commonly 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’

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）[in the use of 在使用……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”和“地学信息学”共同应用于某些活动中―――专属于【pertain to】通常【generally】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

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

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 features 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 33

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）

Distances are not necessarily linear, especially if they occur on the spherical earth. （距离不一定指的是直线的，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。）

Distance between two points can be horizontal, slope, or vertical. （两点之间的距离可以是平距、斜距、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。）

距离之间的关系就确定下来【fix 确定】。）

Ordinary Taping and PreciseTaping（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

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，只要【as long as】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】，C 为或近似为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

（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）

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）

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）

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）

（【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

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，北方向为正，南方向为负）

Similarly, east is considered plus, whereas west is considered minus.（同样的，东为正，西为负）Then the discrepancy should be adjusted by apportioning the closure both in latitudes and in departures on a reasonable basis.（然后差值【discrepancy】应以合理的【reasonable】原则【basis 原则】进行调整【平差】——【by】分配【apportion 分配v.】闭合差到纵距和横距上去）

The adjusted position of each traverse point is determined with respect to some origin.（

An elevation is a vertical distance above or below a reference datum.（高程是高于或低于一个参考基

准的一个垂直距离。）

Although vertical distance can be referenced to any datum, in surveying, the reference datum that is universally employed is that of mean sea level (MSL).（虽然垂直距离可以参考任何一个基准，但是在测量上，这个参考基准一般使用【employ 使用、雇佣】的是平均海平面（MSL））

MSL is assigned a vertical value (elevation) of 0.000 ft or 0.000 m.（MSL 被赋予【assign】一个0.000 英尺或0.000 米的高程）

All other points on the earth can be described by the elevations above or below zero.（地球上所有

其它点可以用高于或低于0 的高程来描述）

Permanent points whose elevations have been precisely determined (benchmarks) are available in most areas for survey use.（高程精确测出的永久点（水准点）被用于【available 可利用、可用到的】大多数区域的测量工作）

In China, 7 years of observations at tidal stations in Qingdao from 1950 to 1956 were reduced and adjusted to provide the Huanghai vertical datum of 1956.（在中国，利用青岛验潮站【tidal stations in Qingdao】从1950 年到1956 年7 年的观测数据处理【reduce 处理、分析、减少】和平差，建立了56 黄海高程系统）In the 1987, this datum was further refined to reflect long periodical ocean tide change to provide

a new national vertical datum of 1985, according to the observations at tidal stations from 1952 to 1979.（1987 年，在依照了【according to】验潮站1952 到1979 年的观测资料后，这个基准【56 基准】被进一步精确【refine 精确、精制v.】——反映长时期海潮变化的85 国家高程基准建立起来。）Although, strictly speaking, the national vertical datum may not precisely agree with the MSL at specific points on the earth’s surface, the term MSL is generally used to describe the datum.（虽

然，严格说来【strictly speaking】，国家高程基准在特殊的【specific 特定的、特殊的】点上与MSL 并不恰好【precisely】吻合，术语MSL 一般【generally】还是用来描述它【国家高程基准】）

MSL is assigned a vertical value (elevation) of 0.000 ft or 0.000 m.（MSL 高程的赋值为0.000 英尺或米）

Difference in elevation may be measured by the following methods:(James M. Anderson and Edward M. Mikhail. 1998)（高程的差异【高差】可以由下列方法测得（詹姆斯.安德森和爱德华.？？？））1. Direct or spirit leveling, by measuring vertical distances directly.（水准测量【Direct leveling、

spirit leveling 都是水准测量的意思】，直接测得垂直距离【高程】）

Direct leveling is most precise method of determining elevations and the one commonly used.（水准

测量是高程测量方法中精度最高、使用最普遍的方法）

2. Indirect or trigonometric leveling, by measuring vertical angles and horizontal or slope distances.

（三角高程测量，利用测量竖直角和水平或斜距来测高程）

3. Stadia leveling, in which vertical distances are determined by tacheometry using engineer’s transit and level rod; plane-table and alidade and level rod; or self-reducing tacheometer and level rod.

（视距高程测量，利用视距测量【tacheometry】，使用工程经纬仪和水准尺；平板仪和照准仪和水准尺；或者自处理视距仪【tacheometer 视距仪、准距仪】和水准尺测得垂直距离【高程】）

4. Barometric leveling, by measuring the differences in atmospheric pressure at various stations by means of a barometer.（气压水准测量【Barometric 大气压力】，通过使用气压计【barometer】测量不同站点大气压力的差值来测高程）

5. Gravimetric leveling, by measuring the differences in gravity at various stations by means of a gravimeter for geodetic purposes.（重力水准测量，通过使用【by means of】重力计测量不同站点的重力值差值来测高程，用于大地测量学的目的）

6. Inertial positioning system, in which an inertial platform has tree mutually perpendicular axes,

one of which is “up”, so that the system yields elevation as one of the outputs.（惯性定位系统，

含有一个惯性平台，具有三个互相【mutually 相互地】垂直【perpendicular 垂直的】轴，其中一个是“向上”的，所以这个系统产生【yield 产生v.】的输出【output 输出n.】其中一个就是高程。）

Vertical accuracies from 15 to 50 cm in distances of 60 and 100 km, respectively, have been reported. （各自地【respectively】，据相关报告，在60 和100km 的距离上，其精度能达到15 到50cm）

number of points with datum elevations are located in the region surveyed.（GPS 高程测量，它的参考面是地球椭球面，但是如果在测区有充分的高程点，可以修正至高程基准上来）Standard deviations in elevation differences of 0.053 to 0.094 m are possible under these conditions. （在这种情况下【上句中的情况】，其高差的标准差【Standard deviation】能够达到0.053 到0.094 米。）Spirit leveling （水准测量）

The most precise method of determining elevations and most commonly use method is direct leveling or spirit leveling which means measuring the vertical distance directly.（精度最高、使用最普遍的高程测量方法就是直接测垂直距离的水准测量方法）

Differential leveling is used to determine differences in elevation between points that are remote from each other by using a surveyor’s level together with a graduated measuring rod.（微差水准测量是利用测量者的水准仪【level 水准仪、水平仪】和【together with】有刻度的【graduated】尺来测定远距离的【remote 遥远的】相隔点的高差）

For example, to determine the elevations of desired point B with respect to a point of known elevation A (see Figure 1), the elevation of which (BM) is known to be above sea level, the level is set up at intermediate point between A and B, and rod readings are taken at both locations as a and b respectively. （例如，确定欲测【desired 想得到的】关于点A 的点 B 的高程，（如图1），A 点的高程已知（BM 点）【above sea level 不用翻译】，在A 和B 点之间的中【intermediate 居中的】点处安置水准尺，分别【respectively 分别地】以a 和 b 代表在这两处水准尺上的读数）

Then the elevation of the line of sight of the instrument (being horizontal) is known to be the line of sight of the instrument HA + a.（那么，仪器（整平后）的视线高程就是：HA + a）【怀疑这句话不对the line of sight of the instrument 多余了】

The elevation of point B can be determined by equation（B 点的高程可以由方程【equation】来确定）HB=HA + a －b

In addition to determining the elevation of point B, the elevations of any other points, lower than the line of sight and visible from the level, can be determined in a similar manner.（除确定B 点的高程之外【In addition to 除……之外】，其它点的高程，低于视线的【高于视线的点，水准仪无法测得读数】和水准仪可以看见的点，都可以以相似的方法得到。）

But some terms should be mentioned from above.（但是上面的一些术语需要提一下）

a is called Backsight (BS) which is a rod reading taken on a point of known elevation in order to establish the elevation of the instrument line of sight.（a 被称为Backsight【后尺读数】，是一个放在已知高程点上的尺的读数，用来求得【establish 建立】仪器视线的高程。）

b is called Foresight (FS) which is a rod reading taken on a turning point, benchmark, or temporary benchmark in order to determine its elevation.（b 被称为Foresight【后尺读数】，是一个放在转点【turning point TP 点】、水准点、或者是临时水准点之上的尺的读数，用来确定该点的高程）HA + a refers to the Height of Instrument (HI) which is the elevation of the line of sight through the level.（HA + a 指的是仪器高度（HI），是过水准仪的视线的高程）

Owing to refraction, actually the line of sight is slightly curved, the effects of curvature and refraction for the horizontal distance can be reduced to a negligible amount and no correction for curvature and refraction is necessary if backsight and foresight distances are balanced in practical operation.（由于【Owing to 因……的缘故】大气折光【refraction 折光】的缘故，实际上视线是有些【slightly 些微地】弯曲的，曲率【地球曲率】和折光的影响可以被当作【be reduced to 被处理为】可忽略的【negligible 可忽略的】值【amount 数量】，不必【necessary 必要的】加入球气改正，如果在实际【practical】工作【operation】中后视距和前视距是相等的【可提前到本句中间】。）

Trigonometric Leveling（三角高程测量）

Trigonometric leveling is used where difficult terrain, such as mountainous areas, precludes the use of conventional differential leveling.（三角高程测量适用于困难地形，例如在山区，不能【preclude 排除v.】使用常规的【conventional】微差水准测量。）

The modern approach is to measure the slope distance and vertical angle to the point in question. （现代的三角高程测量方法是测量到未知点【the point in question】的斜距和垂直角）

from the measured slope distance and vertical height.（全站仪包含了【contain】内置的【built-in 内置的】微处理器，用来根据测得的斜距和垂直角计算和显示水平距离）

This latter facility has resulted in trigonometrical leveling being used for a wide variety of heighting procedures, including contouring.（这种后来的【latter】设备【facility 工具、设备、熟练、容易、敏捷】导致了【result in 导致】三角高程测量被广泛用于多种【a variety of 多种的】高度测量工作【procedure 程序、手续】，包括测绘等高线【contour 等高线】

The basic concept of trigonometrical leveling can be seen from Figure 2.（三角高程测量的基本原理【concept 概念】可以看图2）

When measuring the vertical angle αand the horizontal distance S is used, then the difference in elevation hAB between ground points A and B is therefore:（当我们用α和S 分别表示垂直角和水平距离时，A 点和B 点之间的高差为：）

hAB=S×tanα+i –v

where i is the vertical height of the measuring center of the instrument above A and v is the vertical height of the center of the target above B.（i 是A 点上仪器中心的高度，v 是B 点上目标中心的垂直高度）

The vertical angles are positive for angles of elevation and negative for angles of depression.（垂直角为仰角【elevation 仰角】时为正，俯角【depression 俯角】时为负）

The zenith angles are always positive, but naturally when greater than 90°they will produce a negative result. （天顶距总是正的，但是自然的当超过了90°时，它们将产生一个相反的结果【指的是相对于地平线来说】）

Trigonometrical leveling method of determining difference in elevation is limited to horizontal distance less than 300 m when moderate precision is sufficient, and to proportionately shorter distances as high precision is desired.（普通【moderate 普通的】精度要求下【sufficient 充足的】【precision 精度】，三角高程测量方法测高差水平距离不能超过300m，如果要求高的精度，则要相应【proportionately 相应地】缩短距离。）

For the distance beyond 300 m the effects of curvature and refraction must be considered and applied. （因为超过300m 时，地球曲率和折光影响必需考虑【apply 应用可以不翻译】）

To eliminate the uncertainty in the curvature and refraction correction, vertical-angle observations are made at both ends of the line as close in point of time as possible.（为了消除【eliminate 消除】地球曲率和折光改正【correction 修正、改正】的不确定因素，垂直角观测时应采用在观测方向两端尽量同时【as close in point of time as possible】相向观测的方法。【就是对向观测嘛】）

This pair of observations is termed reciprocal vertical-angle observation.（这种观测称为【is termed】垂直角对向观测【reciprocal observation 对向观测】）

The correct difference in elevation between the two ends of the line is the mean of the two values computed both ways either with or without taking into account curvature and refraction（线两端正确的【correct】高程之差是计算得到的两高程值的平均值【mean】，不管计算有无考虑【take into account】球气差.）

The important notes should be mentioned here is that surveyors used to working with spirit levels have referenced orthometric heights (H) to the “average”surface of the earth, as depicted by MSL.（这里需要注意的是，测量者在水准测量工作中使用的是参考地球“平均”表面的正高，这个平均表面描述为【称为】MSL）

However, the elevation coordinate (h) given by GPS solutions refers to the height from the surface of the ellipsoid to the ground station.（然而，GPS 方法【solution】给出的是地球椭球面到地面站【ground station】的大地高【其实大地高的英文名字应该是：geodetic height，或ellipsoidal height，但这里讲的就是大地高，直接译为大地高】）

Unit 7 Robotic Total Station （智能型全站仪）

For many years, the optical transit was the surveyor’s tool of choice to measure angles.（多年以来，光学【optical】经纬仪一直是测量人员测角的工具选择）

By the 1970s, however, the electronic theodolite began to replace the transit since it could measure

Then in late 1990, Geodimeter, Dandryd Sweden introduced the first “robotic total station”adding automatic tracking and radio communication to a radio and data collector at the “target”or pole. （然后在90 年代后期，瑞典Dandryd【应该是瑞典的一个地名】Geodimeter【公司名】，推出【introduce 介绍、提出】了第一台“智能型全站仪”，在“目标”或测杆上增加了一个有自动跟踪【automatic tracking】和无线电通讯【radio communication】功能的信号和数据收集器）

Thus, for the first time, no person was required at the instrument——only at the target, reducing the size of a survey crew.（这样，第一次，仪器不再需要人——除了目标点，减少了测量人员）Total Station （全站仪）

A total station is the most commonly used instruments now in geomatics engineering, which is fully integrated instrument that capture all the spatial data necessary for a 3-dimensional positional information.（全站仪是现在测绘工程中使用最普遍的仪器，完全综合的【fully integrated 考虑到平时介绍全站仪的词句，我们可以翻译为全站型】仪器，可以获取所有的反映 3 维空间位置信息所需的空间数据。）A total station integrates the functions of an electronic theodolite for measuring angles, an EDM for measuring distances, digital data and a data recorder.（全站仪整合了电子经纬仪的测角功能和EDM 的测距功能，以及？？和数据存储器的功能）

All total stations have similar constructional features regardless of their age or level of technology, and all perform basically the same functions.（不管他们工艺的年代和水平如何，所有的全站仪的结构【constructional 构造的feature 特征】都是类似的【similar】，都能基本【basically 基本地】完成相同的功能）

After the instrument has been set up on a control station, centered, leveled and properly oriented, and the prism target has been set up over another point whose position is to be measured, the surveyor may focus the target and depress a button.（在控制点上安置仪器、对中、整平和恰当的【properly】定向【orient 确定方向、东方】之后，棱镜【prism】目标【目标棱镜】置于测点之上，测量人员就可以照准【focus】目标并按动按钮。）

Then output from the horizontal and vertical circular encoders and from the EDM can be displayed at the instrument and stored in a data collector and enters into a built-in microprocessor.（然后水平和竖直编码【encoder 编码器】度盘和EDM 的输出结果可以显示在仪器上，并可以存储在数据收集里，送入内置的【built-in】微处理器）

The microprocessor can convert the measured slope distance to the horizontal distance using the measured vertical or zenith angle.（微处理器可以将测得的斜距利用测得的竖直角或天顶距转化【convert】为平距）The microprocessor also computes the difference in elevation between the instrument center and the prism target.（微处理器还可以计算仪器中心和棱镜目标【目标棱镜】之间的高差）

If the elevation of the instrument center (the HI) and the height of the reflector target (the HT) above the ground are entered, the microprocessor computes the elevation of the target station taking into account the effect of curvature and refraction.（如果仪器中心的高程（HI）和反射目标到地面的高度（HT）输入仪器，微处理器在考虑【take into account】地球曲率和折光影响后就可以计算出目标站点的高程）

Furthermore the microprocessor can also compute the resolution of the horizontal distance together with the current horizontal direction, expressed as an azimuth, into a coordinate of the target station. （此外，微处理器还可以由水平距离和【together with】当前水平方向——表示为方位角【azimuth】，计算出目标点的坐标）【resolution 分析、决定n.】

In construction layout measurement, the data necessary to establish the direction and distance from a control point to locate a construction point can be entered into the instrument via the keyboard

or directly from an office computer.（在建筑施工放样测量工作中，在控制点上为建筑点位定位所需的方向和距离数据，可以由【via 经过】键盘或直接由办公室的计算机出入到仪器中去）

Then the surveyor guides the person holding the prism along the line of computed direction until the distance to the point to be located agrees with the computed distance.（然后，测量人员引导持棱镜的人沿着计算出的方向线前行，直到到所定点距离于计算出的距离相吻合为止）

All displayed outputs can also be recorded or stored in electronic field book for further calculations

and the vertical motions of these instruments.（80 年代末，全站仪改进【adaption 改变、改写】是加入伺服【servo】电动机【motor】，用以驱动仪器的水平和垂直移动【motion】）

For all the complex electronics inside a robotic total station, the motion is still provided by simple servo motors with a reduction gear system.（在智能型全站仪内所有的复杂的电子元件，它们的活动仍然是由简单的带有一个变速【reduction 变速、减速】齿轮系统的伺服电动机提供的）

The end result must be lightweight, durable and fast and have sub-second positioning accuracy.（最终结果必定是，质量轻【原文应该是light weight，中间有空格；lightweight 的意思是轻量级选手、不胜任者】，耐用的和快速的、有着亚秒级定位精度的）

When those total stations have been designed with automatic target recognition (ATR) function, they allow the user to automatically track, measure and record targets.（当带有自动目标识别功能【automatic target recognition】的全站仪被设计出后，自动跟踪【track】、测量和记录目标得以实现。）Current technology provides robotic (motorized) total stations that are able to measure angles with an accuracy of ±0.5″and distances with an accuracy of ±1mm+1ppm to a range of 3500m.（当前的技术能够使智能型全站仪在3500m 的范围内的测角精度达到±0.5″，测距精度达到±1mm+1ppm）Latest models are capable of searching automatically for targets and then locking onto them precisely, turning angles automatically to designated points using the uploaded coordinates of those points, repeating angles by automatically double-centering, and even equipped with automatic data transfer systems.（最近的样式可以自动搜寻目标并将其精确锁定，自动转角到指定【designated】点——利用上载的【uploaded】这些点的坐标，通过自动两次置中复测角度，甚至装备了自动数据转换系统）These instruments, when combined with a remote controller held by the prism surveyor, enable the survey to proceed with a reduced need for personnel.（这种仪器，当与一个可被持镜【prism 棱镜】测量者持有的遥控装置【remote controller 遥控装置】结合后，测量工作就可以减少人员【personnel 人员n.】的需要）All these characteristics make the robotic total stations very useful for geomatics engineering tasks. （所有这些特性使得智能型全站仪在测绘工程任务当中非常有用）

Using a robotic total station with ATR, first, the telescope must be pointed roughly at the target prism—either manually or under software control—and then the instrument does the rest.（使用带有ATR 的智能型全站仪时，首先，望远镜必需大致地【roughly 粗略地】照准目标棱镜——或者手工【manually 用手adv.】或者软件控制——然后省下的就交给仪器去做了）

The ATR module is a digital camera that notes the offset of the reflected laser beam, permitting the instrument then to move automatically until the cross hairs have electronically set on the point precisely.（ATR 模块是一个数字照相机，可以记录【note】反射激光束的偏移量【offset】，使得【permit 使……有可能】仪器能够自动移动【转动】，直至十字丝电子的调整到正好【precisely】照准那个点）After the point has been precisely “sighted”, the instrument can then read and record the angle and distance.（当该点被正好“看到”，仪器就可以读出并记录角度和距离）

Reports indicate that the time required this process is only one-third to one-half of the time required to obtain the same results by conventional total station techniques. （有报告指出【indicate】，该过程所需时间仅是使用常规【conventional 常规的、传统的】全站仪获得同样结果所需时间的一半或三分之一）With the proper ATR-based instrument Leica TCA2003, the surveyor will be able to handle new applications and address existing jobs with a different spin.（利用基于A TR 的Leica TCA2003，测量者将可以从事新的工作）

【application 应用】

【即干以前干不了的活】，也可以以不同的方式【spin 方式、风格；旋转】从事【address 从事v.】现有的工作）

Because of the co-axial target detection system and the use of conventional EDM prisms, daily operation will remain unchanged.（因为同轴【co-axial 同轴的】目标探测【target detection】系统和常规EDM 棱镜的使用，例行的【daily 日常的、例行的】操作保留没有变）

What will change is the speed with which data is collected.（改变的是数据采集的速度）Topographical surveys are automated by putting the TCA in Auto-record mode—the instrument follows the rod person and automatically records a point at specified distances, time intervals, or whenever

使用者为下个导线点作准备时，TCA2003 可以连贯地【even】转过若干组角度）

Take automation a step further and do some “no-man”surveying. Robotic total stations are already

being used in hazardous areas to provide continuous monitoring of structures or processes.（将自动

化更进一步，用于一些“无人”测量工作。智能型全站仪已经被应用于危险领域，用来提供对建筑物或活动的持续的监测）

Certain sites link measurement systems with civil defense agencies and law enforcement groups.（某

些【Certain】场合【site】下将测量系统与民防机构和执法【law enforcement】团体联系起来）

An offspring of “no-man”surveying is machine guidance.（无人测量的一个产物是机械的导向。）

TCAs guide road headers, tunneling moles and paving machinery.（TCAs 引导巷道掘进机【roadheade】、

隧道掘进机【tunneling mole】【mole 鼹鼠】和筑路【paving】机械）

A surveyor is in charge of installing the robotic survey station at predetermined locations and lets

the robotic unit inform machine operators where they are relative to design information.（测量者在

预定【predetermined 预先设定】位置【location】负责智能全站仪的安装【install】，让它通知仪器操作者——他们与设计信息相比较所在的位置【相对于设计点的位置】）

The machine operator reads the machine position from a small display receiving position updates from

a base station. （仪器操作者在一个小显示器中读出从基准站上传来的的仪器所在位置）

The base station can be robotic, GPS or a combination of a number of sensors.（这个基准站可以是智

能型全站仪站点，GPS 站点或者许多传感器的联合站点）

Unit 88 Errors n n n in Measurement（测量工作中的误差）

Measurements are defined as observations made to determine unknown quantities.（测量被定义为确定未知量【quantity】的观测）

They may be classified as either direct or indirect.（它们可以被分为直接观测和间接观测）

A direct measurement is one where the reading observed represents the quantity measured, without a need to add, take averages or use geometric formulas to compute the value desired.（直接观测就是观测读数即代表了【represent 代表、描述】测量量，不需要另外加、取平均或利用几何【geometric 几何的】公式【formulas】来计算出所需【desired 想得到的】值。）

Determining the distance between two points by making a direct measurement using a graduated tape is an example of direct measurement.（用一把刻度尺直接确定两点之间的距离，就是一个直接观测的例子）

An indirect measurement requires calculation and can be determined from its mathematical relationship to direct measurements when it is not possible or practical to make direct measurements.（间接观测需要计算，当直接观测是不可能或不实际【practical 实际的】时，可以利用它与直接观测量之间的数学关系来确定。）

For example, station coordinates can be mathematically computed by measuring angles and lengths of lines between points directly.（例如，测点【station 测点】坐标可以由直接测得的点之间直线的角度和长度来计算）Therefore the indirect measurements (computed station coordinates) contain errors that were present in the original direct observations and propagated (distributed) by the computational process.（因此，这个间接测量值（计算出的测点坐标）包含了初始【original】直接观测出现【present】的和由计算过程传播【propagate】（散播的）的误差。）【that 后面全都是修饰errors 的】

This distribution of errors is known as error propagation.（这种误差的散播被认为【be known as 被称为】误差传播）Also, it is the indirect nature of measurements that forces the need to often apply some rather sophisticated mathematical procedures to analysis of errors and thus determine a “best value”to represent the size of the quantity.（同样，间接测量的特性需要【forces the need to 使……成为需要】经常应用一些更复杂的数学方法【procedure】来分析误差并从而确定“最佳值”来代替【represent 代替、代表、扮演、表现】测量值的大小）

It can be stated unconditionally that all measurements, no matter how carefully executed, will contain error, and so the true value of a measurement is never known, and the exact sizes of the errors present are always unknown.（可以绝对地【unconditionally 无条件地】说【state 声明】，所有测量工作，无论多么仔细的实行【execute】，也会包含误差，因此测量的真值是永远不知道的，出现【present 出现】的确切的【exact】误差大小也永远不知道）

Even with the most sophisticated equipment, a measurement is only an estimate of the true size of a quantity.（即使使用最复杂精密的装置，测量值也仅仅是一个量的真值的估计【estimate】）

This is because the instruments, as well as the people using them are imperfect, because the environment in which the

当【as】仪器的改进，环境条件改善和观测者技术【ability】的进步时。但是它们永远不能达到真值）

By definition, an error is the difference between a measured value for any quantity and its true value.（按照【By】定义，误差是某一量的测量值和它的真值之间的差值。）

The sources of errors fall into three broad categories which are described as follows:（误差来源分成【fall into 分成、属于、落入】三个主要的【broad】类型【category】，描述如下：）

Instrumental Errors.（仪器误差）These errors are caused by imperfections in instrument construction or adjustment.（这种误差由仪器的结构和调节装置不完整性引起）

For example, the divisions on a theodolite or total station instrument may not be spaced uniformly.（例如，经纬仪或全站仪中的刻度【divisions，division 原意指分离、分开，这里指刻度】没有被均匀地【uniformly】分划【即刻度分划不均】）

These error sources are present whether the equipment is read manually or digitally.（这种误差源出现在不论是人工【manually 人工地】读取还是数字式读取的仪器上）

Natural Errors. （自然【环境】误差）These errors are caused by variation in the surrounding environment conditions, such as atmospheric pressure, temperatures wind, gravitational fields, and magnetic fields, etc.（这种误差是由周围环境条件的变化【variation】引起的，如大气压力，温度，风力，重力场，和磁场）

Personal Errors.（人为误差）These errors arise due to limitations in human senses, such as the ability to read a micrometer or to center a level bubble.（这种误差出现【arise 出现v.】由于【due to 由于adv.】人类的感官局限性【limitation 局限性】）

The sizes of these errors are affected by personal ability to see and by manual dexterity. （这种误差的大小受到人看的能力和手的灵活性【dexterity 灵活n.】的影响）

These factors may be influenced further by temperature, insects, and other physical conditions that cause humans to behave in a less precise manner than they would under ideal conditions.（这种因素受温度、蚊虫【insect 虫】和其它引起人不精确行为的自然条件的影响比在理想条件下所受的要大）

From the discussion thus far it can be stated with absolute certainty that all measured values contain errors, whether due to lack of refinement in readings, instabilities in environmental conditions, instrumental imperfection or human limitations.（从以上【thus far 迄今】我们的讨论中，可以绝对确定的【certainty 确定n.】说【state 声明】，所有测量值都有误差，不论是归咎于【due to 归于】读数缺乏精确、环境条件的不稳定性【instability】、仪器的不完整性【imperfection】还是人的局限性【limitation】）

Some of these errors result from physical conditions that cause them to occur in a systematic way, whereas others occur with apparent randomness.（这些误差中有些由物理条件产生【result from 由……产生】的，使它们以系统的方式发生【表现为系统性】，而【whereas】其它的表现为外观上的随机性【randomness】）

Accordingly, errors are classified as either systematic or random.（因此【Accordingly】，误差分为系统误差和随机误差【偶然误差】）

But before defining systematic and random errors, it is helpful to define mistakes. （但是在定义体统误差和随机误差前，先来定义下错误对我们很有帮助）These three terms are defined as follows: （下面是这三个术语的定义）1. Mistakes.（错误）Mistakes or blunders (gross errors) actually are not errors because they usually are so gross in magnitude compared to the other two types of errors.（错误或粗差【blunder 大错误，gross 粗的】实际上不是误差，因为它们相对于其它两种误差在量级【magnitude 大小、量级】上通常太粗了）

Carelessness, inattention, improper training, bad habits, poor judgment, adverse measuring or observing conditions, and various negative attitudes and emotions are the traces or the common reasons for mistakes.（粗心、疏忽、不恰当的【improper】训练、不好的习惯、错误的判断、不利的【adverse 不利的】观测条件，和各种消极态度和情绪是引起错误的普遍原因【trace 线索、轨迹】）

They are not classified as errors and must be removed from any set of observations. （它们不能被分进误差里，必需从观测中从予以移除）

Typical examples of mistakes are omitting a whole tape length when measuring distance, sighting the wrong target in a round of angles, writing down 27.55 for 25.75 in recording. （错误的典型的例子如测距时遗漏掉了一个尺段的长度，在测一系列【in a round of】角时对错了目标，在记录时将27.55 写成了25.75）

Therefore great care must be taken to obviate them.（因此必需非常仔细的消除它们）

Mistakes will never be completely eliminated from measurements, but surveyor’s careful, attentive, conscientious

理论和实践上的理解，错误可以得到限制【control】和大致【practically 大致、几乎】消除）

2. Systematic Errors.（系统误差）Systematic Errors are defined as those errors whose magnitude and algebraic sign can be calculated and applied as a correction to the measured quantity, or these errors follow some physical law and thus can

be predicted.（系统误差定义为，大小【magnitude】和符号【algebraic sign 代数符号】上可以被计算，并当作修

正值应用在测量量上，或者说这些误差遵循某些自然法则【physical law】因而可以被预知【predicte】）

Some systematic errors are removed by some correct measurement procedures (e.g. , balancing backsight and foresight distances in differential leveling to compensate for earth curvature and refraction). （有些系统误差可以由某些恰当的测量程序来消除（举例来说【e.g.举例来说】，在微差水准测量中使前后视距相等来低偿【compensate】地球曲率和

折光）

Others are removed by deriving corrections based on the physical conditions that were responsible for their creation (e.g., applying a computed correction for earth curvature and refraction on a trigonometric leveling observation). （有些【others 和some 对比使用时, 是“有些”的意思而不是做“其他”讲】系统误差则是利用推出【derive 得来、得出、推出】改正值来消除，【based on 后面是讲改正值怎么得到】改正值是基于它们产生的原因的物理条件推出）Surveyors should know how to deal with systematic errors.（测量者应该知道怎样处理体统误差）

The first requirement is to recognize and accept the possible existence of errors. （第一个要求是认可并承认误差的存在可能性）

Next, identify the various sources that might be affecting a reading systematically, then, determine what the “system”is. （接下来，辨别可能系统地影响到读数的不同的来源，然后确定这个“系统”是什么【是什么在系统的影响读数】。）Is it a constant, linear, or in proportion to the size of the quantity being measured? Or, does it follow some other mathematical relationship? Is there some physics involved?（它是常量【constant】？是线性的【linear】？还是和被测量的大小成比例【in proportion to】？还是，它遵循其它一些数学关系？和物理过程有关吗？）

Once systematic errors discovered and quantified, the errors can be essentially compensated by certain processes of measuring or corrected to reduce their effect.（一旦系统误差被发现和量化【quantify】，误差就可以得到实质的【essentially 实质地】低偿，【by 后面是低偿的方法】利用某一【certain 某一个】测量过程或者修正来减少它们

的影响）

Careful calibration of all instruments is an essential part of controlling systematic errors. （仪器的仔细的校准【calibration 校准n.】，是控制系统误差的本质的一方面）

3. Random Errors.（随即误差）Random (also known as accident) errors are introduced into each measurement mainly because of human and instrument imperfections as well as uncertainties in determining the effects of the environment on measurements.（随机（也叫偶然）误差引入每个测量工作中，主要因为人和仪器的不完美性，如同环境对测量工

作的影响的不确定性）

After all mistakes and systematic errors have been removed from the measured values, the random errors remain.（在所

有的错误和系统误差被移除出测量值后，剩下的就是随机误差）

In general, random errors are unavoidable and relatively small.（通常【In general】，随即误差是不可避免的并且相对

较小）

They usually do not follow any physical law, but follow random patterns, or the laws of “chance”.（它们通常并不遵循任何物理法则，但却遵循随机模式【pattern 模式、式样】，或概率法则）

They have unknown signs and are as likely to be negative or positive.（它们符号不可知，可能是正或是负）

The magnitude of such an error is unknown, but it can be dealt with and estimated according to the mathematical laws of probability.（这样的【such】误差的大小【magnitude】未知，但是可以依照【according to】数学的概率论【laws of probability 概率论】来处理和估计【estimate】）

Examples of random errors are (a) imperfect centering over a ground point during distance measurement with an EDM instrument, (b) bubble not centered at the instant a level rod is read, and (c) small errors in reading graduated scales.（随

机误差的例子如(a)在使用EDM 测距时没有完全【imperfect 有缺点的、未完成的】对中地面点，(b) 在水准尺上读数时【at the instant 在……时】气泡没有居中(c)读刻度尺时的小误差）

Understanding the nature of random errors helps to understand why random errors are never really fully corrected, since

the observation of the physical phenomena contains personal, random errors.（对随机误差特性的理解有助于理解为什

么随机误差永远不能真正【really】完全的【fully】修正，因为对物理现象的观测包含了个人的，随机误差）Thus, measurements have “uncertainties”or random errors that remain unquantifiable.（Random errors are dealt with by