测量是关于确定地球表面上或接近地球表面的点的相对空间位置。它是测量物体之间水平与垂直距离、测量线条之间夹角、确定线条方向以及通过预先确定角测量法和线性测量法来建立点的技术。
Accompanying the actual measurement（度量）of survey are mathematical calculations. Distance, angles, directions, locations, elevations, areas, and volumes are thus determined from data of survey. Also, much of the information of the survey is portrayed graphically（图示描述）by the construction of maps, profiles（纵剖面图）, cross sections（横剖面图）, and diagrams(图表）.

数学计算伴随着测量中的实际量度。根据测量数据就可确定距离、角度、方向、位置、标高、面积以及体积。而且，测量中的很多信息是通过绘制地图、纵横剖面图和图表，以图示形式被描述。
The equipment available and methods applicable for measurement and calculation have changed tremendously in the past decade. Aerial photogrammetry（航空摄影测量）, satellite observation, remote sensing, inertial surveying（惯性测量）, and electronic distance measurement（电子测距）laser techniques are examples of modern systems（现代方法）utilized to collect data usable in the surveying process. The relatively easy access to（利用）electronic computers of all size（各种容量）facilitates the rigorous（精确的）processing and storage（处理和储存）of large volumes of data.
对测量和计算，可利用的设备和可应用的方法在过去十年中已经发生了惊人的变化。航空摄影测量、人造卫星观测、遥感、惯性测量以及电子测距激光技术是现代方法中的例子，被用来收集测量过程中可使用的数据。较容易地利用各种容量的电子计算机有助于精确地处理和储存大量的数据。
With the development of these modern data acquisitions（收集）and processing systems, the duties of the surveyor have expanded beyond（超出）the traditional tasks of the field（现场）work of taking measurements and the office work of computing and drawing. Surveying is required not only for conventional construction engineering projects（项目）, mapping, and property（地籍）surveys, but is also used increasingly by other physical sciences, such as geology（地质学）and geophysics（地球物理学）; biology, including agriculture, forestry, grasslands（草原）, and wildlife（野生动植物）; hydrology（水文地理学）and oceanography（海洋学）; and geography, including human and cultural resources（人文资源）.
随着现代数据收集和处理系统的发展，测量员的职责已经超出了传统的现场进行测量和室内进行计算和制图的任务。不仅一般的建筑工程项目、绘制地图、地籍测量需要测量，而且也越来越多地用于其他的自然科学，如地质学和地球物理学；生物学，包括农业、林业、草原和野生动植物；水文地理学和海洋学；以及地理学，包括人文资源。
The tasks in these physical science operations（活动）need to be redefined to include design of the surveying procedure（程序）and selection of equipment appropriate for the project; acquisition of data in the field or by way of remote station; reduction（整理）or analysis of data in the office or in the filed; storage of data in a form compatible with（适合于）feature retrieval（特征检索）; preparation（整理）of maps or other displays in the graphical（绘图）(including photographic摄影) or numerical form needed for the purpose of survey; and setting of monument（界标）and boundaries in the field as well as control for construction layout（施工放样）. Performance of these tasks requires a familiarity with the uses of surveying, knowledge of fundamentals of the surveying process（方法）, and knowledge of various means by which data can be prepared for presentation.
这些自然科学活动的任务需要重新定义，包括设计测量程序和选择适合该项目的设备；在现场或通过远距离的测站收集数据；在室内或现场整理或分析数据；以适合于特征检索的形式储存数据；以测量所需的绘图（包括摄影）或数字形式整理地图或其他显示；在现场设置界标和边界并控制施工放样。这些任务的实施需要熟悉测量的使用、测量方法的基本原理的知识以及数据准备表达的不同方法的知识。
The earliest surveys known were for the purpose of establishing（确定）the boundaries of land, and such surveys are still important work of many surveyors.

最早了解的测量是用来确定土地的边界，这样的测量仍然是很多测量员的重要工作。
Every construction project of any magnitude（规模）is based to some degree upon measurements taken during the progress（发展）of a survey and is constructed about lines and points established by the surveyor. Aside from land surveys, practically all surveys of a private nature（私营性质）and most of those conducted by public agencies（公共机构）are of assistance in the conception（规划）, design, and execution （施工）of engineering works.

在测量的发展过程中，任意规模的每个建筑项目在某种程度上都是根据所采用的测量方法，然后绘制由测量员确定的线和点。除了土地测量外，实际上所有私营性质的测量和大多数由公共机构经营的测量都对工程的规划、设计和施工有帮助。
For many years the government, and in some instances（在某些情况下）the individual states, have conducted surveys over large areas for a variety of purposes. The principal work so far（迄今为止）accomplished consists of the fixing（确定）of national and state boundaries; the charting（绘制）of coastlines（海岸线） and navigable（适于航行的）streams and lakes; the precise location（定位）of definite reference points（固定基准点）throughout the country; the collection of valuable facts（论据）concerning the earth’s magnetism（磁力） at widely scattered stations; establishment（建立）and observation of a greater network of gravity station（重力站）throughout the world; the establishment and operation（运转）of tidal and water level （潮位和水位）station; the extension（扩充）hydrographic（与水文地理学有关）and oceanographic（与海洋学有关）charting and mapping（绘制）into the approximately three-fourths of the world which is essentially（本来）unmapped; and the extension of topographic（地形的）mapping of the land（陆地）surfaces of the earth.