（【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.（
This position is defined by its Y coordinates and its X coordinates with respect to a plane rectangular coordinate system in which the Y axis is assumed north-south whereas the X axis east-west.（其位置 由平面直角坐标系的 Y 坐标和 X 坐标来定义，Y 轴代表【assume 担任（不是假定的意思）】南北方向，而【whereas 反之】X 轴代表东西方向【和测量学不一样？？】）
Unit 6 Methods of Elevation Determination（高程测量方法）
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） The equipment cost is extremely high and applications are restricted to very large projects where terrain, weather, time, and access impose special constraints on traditional methods.（这种装置成
本极【extremely 极端地】高，只限于【restricted 受限的】非常大的项目，这些项目地质、气象、授时、以及？？ 施加【impose】特殊限制【constraints】在传统方法上【即，在这些项目上传统测量方法受限】） 7. GPS survey elevations are referenced to the ellipsoid but can be corrected to the datum if a sufficient
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）
Slope distance is measured using electromagnetic distance measurers and the vertical (or zenith) angle using a theodolite, or the total station that integrate these two instruments into a single instrument.
（斜距由电磁波测距仪【measurer 测量器】测得，垂直角（或天顶距）由经纬仪测得，或者利用整合【integrate 整合 v.】了这两种仪器为一体的全站仪来测）
Total stations contain built-in microprocessors that calculate and display the horizontal distance
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 α and 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
angles more accurately on both the horizontal and vertical axes.（然而，20 世界 70 年代，由于【since】 它在水平轴和垂直轴方向上测角更精确【就是水平角竖直角】，电子经纬仪开始代替经纬仪。） In the early 1980s, “total stations,” which measure distances very accurately by using electronic
distance meters (EDMs), became the instrument of choice.（80 年代早期，采用 EDMs 非常精确的测距的全 站仪，成为测量仪器的选择。）