A good draughtsman can plot a length to within 0.25 mm and so, if a plan of an area is required at a scale of distance is 0.25 m.Thus, for a survey at 1/1000 scale, all the measurements must be taken such that the relative positions of any point with respect to any other must be determined to 0.25 m or better.
一个好的绘图员可以在大约0.25mm的范围内画图，假如一个地区的图纸比例尺要求是1/1000，即1mm图上距离代表1m实际距离，那么最小的测距应该是0.25m。因此，对于1/1000比例尺的测量，所有测量必须保证任意一点与其他任意点的相对位置不得大于0.25m。
Random errors are really all those discrepancies remaining once the blunders and systematic errors have been removed.Even if a quantity is measured many times with the same instrument in the sane way, and if all sources of systematic error have been removed ,it is still highly unlikely that all results will be identical.The differences, caused mainly by limitations of instruments and observers, are random errors.
偶然（随机）误差事实上是除去粗差和系统误差后仍存留的偏差。即使一组数据以同样的仪器同样的方法重复测量了很多遍，而且排除了所有能引起系统误差的因素，所有的结果仍然极有可能不是一致的。这种主要由仪器和观测者的局限性引起的误差就是 偶然（随机）误差。
Horizontal and vertical angles are fundamental measurements in surveying.It is neceary to be familiar with the meanings of certain basic terms before describing angle and direction measurement.The terms discued here have reference to the actual figure of the earth.
水平角和垂直角是测量的基本要素，在描述角度和方向测量之前必须熟悉一些基本术语的含义。这里讨论的术语会参考实际的地球参数。
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.
水平角是在一个水平面内由两个与其垂直的相交平面形成的，两条线之间的角度是他们在水平面内投影的角度。
A vertical angle is an angle measured in 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.Plus and minus vertical angles are sometimes referred to as elevation or depreion angles, respectively.
竖直角是在一个垂直面上参考一条水平线或天定方向的竖直线加上（仰）或减去（俯）得到的。正负竖直角有时分别称作仰角或俯角。
A horizontal angle in surveying has direction or sense; that is it is measured or designed to the right or to the left or it is considered clockwise or counterclockwise.In the above figure,the angle at A from B to C is clockwise and the angle from C to B is counterclockwise.
测量中的水平角是有方向或指向的；也就是说，在测量或设计中，它分为右角或左角，或者顺时针和逆时针。上图中，在A点的角度从B到C是顺时针方向，从C到B是逆时针方向。An elevation is a vertical distance above or below a reference datum.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) .
译：海拔是高于或低于一个基准面的垂直距离。尽管在测量中垂直距离可以相对于任何基准面得到，但经常采用的是平均海平面（MSL）。
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.However,the elevation coordinate (h) given by GPS solutions refers to the height from the surface of the ellipsoid to the ground station.
译：这里需要提到重要的几点是，测量人员用直接水准测量得到的正高（H），其参考面是地球平均表面，即水平表面（MSL）。然而，GPS给出的高程（h）指的是从椭圆表面到测站点的高度。
In almost allsurveying operations the number of quantities actually measured is greater than the geometrically neceary minimum, the simplest example of this is the measurement of all three angles of a plane triangle although the geometrical shape is determined by measuring only two 译：几乎在所有的测量工作中，实际观测量的个数都大于几何上必要的观测个数，最简单的例子就是测量平面三角形的三个角度，尽管 这个几何形状只要测量两次就已经被决定了。
An adjustment operation is a procedure for deriving a set of quantities that are consistent among themselves and differ by acceptably small amounts from observed values.In the case mentioned above, alternations totaling + 4 would produce angles having the correct total,trigonometrical formulas sound then be applied to those angles without causing confusion
释：一个平差操作是来自观测值的源于一系列相互一致的和少量可接受的不同的数值的程序步骤。在上面的案例中，交替完全加4”会产生正确的角度总数，三角法公式完全的然后没有混淆的应用于那些角度。
The task of adjustment computation is to “adjust” these discrepancies such that the adjusted quantities are as close as poible to zhe true value.In zhe course of the adjustment computations we also want to determine the accuracy of the observed and adjusted quantities.These tasks call be accomplished in various ways, e.g., graphical adjustment or adjustment according to least squares.The last method was developed in 1794 by Gau.It has, as opposed to all other methods, the advantages that the discrepancies are not adjusted in an arbitrary manner, that it yields sensible values for the adjusted quantities, and that it makes use of statistical theorems
释：平差计算就是“调整”这些不符值，以便使平差值尽可能接近其真值。在平差计算过程中，我们还想确定观察的精度和调整的数量，以上任务用多种方法调用完成，例如，图形调整或者依据最小二乘法调整。后一个方法是高斯在1974年发明的。这种方法与其他方法不同，它有许多优点：不符值不是以任意的方式进行调整的，对平差量可以产生合理的数值，并可以利用统计原理。
All satellite positioning systems provide ground coordinates of a receiver (or the baseline vector between a pair of receives) in an earth-centered coordinate system.The orientation of the system is determined by the tabulated coordinates or ephemerides of the GPS satellites.in order to relate coordinates determined by GPS surveying to the local geodetic datum a transformation relationship needs to be established.
译文：所有卫星定位系统都提供接收机的地心坐标系的坐标（或两个接收机之间的基线矢量。系统的定向由坐标表或GPS卫星的星历确定。为了将GPS测量确定的坐标与地方大地基准联系起来，需要建立起转换关系）
When four satellites are observed simultaneously, it is poible to determine the three-dimensional position of the ground receiver, and the receiver clock offset, at a single epoch.This is simply resection by distance,in surveying terminology,with the technique the precision is a function of the geometry of the receiver in relation to the four visible satellites.The best geometry would be when the satellites are in each of the four quadrants and each at an elevation angle of 40~70 above the
horizon.However, pseudo-range measurements are not nearly as phase measurements of the carrier wave itself.译文：当同时观测四个卫星时，就可以在单个历元确定地面接收机的三维位置以及接收的钟差。用测量术语来说，这就是简单的后方交会，GPS定位的精度受接收机与四个可视卫星的几何图形的影响。最佳的图形是：四个卫星分布在四个象限，并且每个高度角位于水平线以上的40~70之间。但伪距离测量的精度远不如载波相位测量的精度 Its most important feature is the fact,that the objects are measured without being touched.其最重要的特性是不接触被测物体。
Therefore，the term remote sensing is used by some authors instead of photogrammetry .Remote Sensing is a rather young term, which was originally confined to working with aerial photographs And satellite images, Today,it includes also photogrammetry,although it is still aociated rather with image interpretation.
因此，遥感这个词被作者用来代替摄影测量，遥感是个很新的词。它最初限于对航空相片和遥感影像的作业。现在，虽然遥感仍更多的和影像解释联系在一起，但它也包含摄影测量。 Among the users of close range photogrammetry are architects and civil engineers(to supervise buildings,document their current state,deformations or damages),archaeologists,surgeons(plastic surgery) or police departments (documentation of traffic accidents and crime scenes),just to mention a few.
近景摄影测量的使用者中有考建筑师和土木工程师（用于管理建筑物，建立建筑物当前状态，变形或破坏的文档）考古学家，外科医生（整形外科）或警察局（建立交通意外和犯罪现场文档）等，这只是众多用户中的很少一部分。
We may distinguish three important stages of working with geographic data:
Data preparation and entry:the early stage in which data about the study phenomenon is collected and prepared to be entered into the system;
Data analysis: the middle stage in which collected data is carefully reviewed and,for instance ,attempts are made to discover patterns;
Data presentation: the final stage in which the results of earlier analysis are presented in an appropriate way.
译：我们可能会把地理数据的处理分成三个阶段：
数据的准备和输入：初期阶段是收集和准备研究现象的的数据，并输入到系统中。 数据的分析：中间阶段是仔细检查收集到的数据，实际上，是努力发现模式。
数据的的显示：最后阶段就是将早期的分析结果以适当的方式显示。
The U.S.Geological survey offers a frequently cited definition of GIS:"A computer system capable of capturing,storing,analyzing,and displaying geographically referenced information ;that is,data identified according to location."
美国地质测量局对GIS的定义广为引用：“GIS是指可以获取、存储、分析以及显示地理参考信息的计算机系统，也就是说，根据位置识别数据”
Typical planning projects require data sources, both spatial and non-spatial, from different institutes, like mapping agency ,geological survey,soil survey,forest survey, or the census bureau.These data sources may have different time stamps,and the spatial data may me in different scales and projections .With the help of a GIS, the maps can be stored in digital formin a database in worldcoordinates.
典型的规划项目需要空间数据源和非空间数据源，比如制图部门，地质测量，土壤测量，森林测量或人口普查等不同机构的数据。这些数据源现势性，空间数据的比例尺和投影可能
都不同。在GIS的帮助下，地图可以以世界坐标格式存储到数据库中。
Spatial data handling involves many disciplines.We can distinguish disciplines that develop spatial concepts,provide means for capturing and proceing of spatial data, provide a formal and theoretical foundation, are application-oriented, and support spatial data handling in legal and management aspects。
空间数据的处理包括很多的规则。我们可以对这些规则加以区分来加深对空间概念的理解、提供空间数据的获取及处理方法。提供基础公式和理论、应用方向并支持空间数据逻辑处理及管理。
Is subject to 受影响的
The scale of the plot 绘图比例尺
Plottable error 绘图误差
Gro error 粗差
Systematic error 系统误差
Random erroe 随机。偶然误差
Normally distributed 正态分布
Redundant observations 多于观测
Horizontal angle 水平角
Vertical angle 垂直角
Depreion angle 俯角
Zenith distance 天顶距
Elevation angle 高度角
Horizontal circle 水平刻度盘
Vertical circle 垂直度盘
True north 真北
Geodetic azimuth 大地方位角
Grid bearing 坐标方位角
Gyro azimuth 陀螺方位角
Magnetic azimuth 磁方位角
reference datum：参考基面，参考基准面；
Huanghai vertical datum of 1956：黄海高程系统；
national vertical datum of 1985：国家高程基准；
direct leveling，spirit leveling：几何水准测量；
differential leveling：微差水准高程;
trigonometric leveling：三角高程测量；
barometric leveling：气压水准测量;
gravimetric leveling：重力水准测量；
river-croing leveling：跨河水准测量；
BM（benchmark）：水准基点；
level rod：水准尺；
height of instrument（HI）：仪器高;
height of target（HT）目标高；
elevation difference：高差；
annexed leveling line：符合水准路线；
closed leveling line：闭合水准路线；
spur leveling line：支水准路线；
refraction correction：折光差改正；
elevation of sight：视线高程；
optical level：光学水准仪；
electronic level：电子水准仪；
automatic level，compensator level：自动安平水准仪 Adjustment by observation equations 间接平差 Adjustment by condition equations 条件平差 Adjustment of direct observations 直接平差 SurveyAdjustment 测量平差
The least squares methods 最小二乘法
as it happens 碰巧；偶然发生
Data acquisition 数据采集，数据获取
Geodetic datum 大地基准，测地基准点
Differential mode 差分式，差分法
Integer cycle ambiguity 整周不定值 整周模糊度 Standard positioning service 标准定位服务
Precisepositioning service 精确定位服务 Multipath effects 多路径效应
Carrier phase 载波相位
Topographic map 地形图
Thematic map 专题地图
Rectitied photograph 纠正相片
Close range photogrammetry近景摄影测量学 Terrestrial photogrammetry 地面摄影测量学 Double projection 双向投影仪
Analytical plotter 解析测图仪
Geographic Information System地理信息系统 analogue 相似物，类似物
