Surveying

This article is about measuring positions on Earth. Forother uses, see Survey.Surveying or land surveying is the technique, profes-

A surveyor at work with an infrared reector used for distancemeasurement.

sion, and science of determining the terrestrial or three-dimensional position of points and the distances and an-gles between them. A land surveying professional iscalled a a land surveyor. These points are usually onthe surface of the Earth, and they are often used to estab-lish land maps and boundaries for ownership, locationslike building corners or the surface location of subsur-face features, or other purposes required by governmentor civil law, such as property sales.Surveyors work with elements of mathematics (geometryand trigonometry), physics, engineering and the law.They use equipment like total stations, robotic total sta-tions, GPS receivers, prisms, 3D scanners, radios, hand-held tablets, digital levels, and surveying software.Surveying has been an element in the development ofthe human environment since the beginning of recordedhistory. The planning and execution of most formsof construction require it. It is also used in transport,communications, mapping, and the denition of legalboundaries for land ownership.

1 ACSM denitionsThe American Congress on Surveying and Mapping(ACSM),denes surveying as the science and art of mak-ing all essential measurements to determine the relative po-sition of points or physical and cultural details above, on,or beneath the surface of the Earth, and to depict them

in a usable form, or to establish the position of points ordetails.Also per ACSM, the type of surveying known as landsurveying is the detailed study or inspection, as by gath-ering information through observations, measurements inthe eld, questionnaires, or research of legal instruments,and data analysis in the support of planning, designing,and establishing of property boundaries. It involves there-establishment of cadastral surveys and land boundariesbased on documents of record and historical evidence, aswell as certifying surveys (as required by statute or localordinance) of subdivision plats or maps, registered landsurveys, judicial surveys, and space delineation. Land sur-veying can include associated services such as mappingand related data accumulation, construction layout sur-veys, precision measurements of length, angle, elevation,area, and volume, as well as horizontal and vertical con-trol surveys, and the analysis and utilization of land surveydata.

2 HistorySee also: Cadastre History, Cartography History andTopographic mapping History

2.1 Ancient surveying

Basic surveyance has occurred since humans built therst large structures. The prehistoric monument atStonehenge (c. 2500 BC) was set out by prehistoric sur-veyors using peg and rope geometry.[1]

In ancient Egypt, a rope stretcher would use simple geom-etry to re-establish boundaries after the annual oods ofthe Nile River. The almost perfect squareness and north-south orientation of the Great Pyramid of Giza, built c.2700 BC, arm the Egyptians command of surveying.The Groma instrument originated in Mesopotamia (early1st millennium BC).[2]

The mathmetician Liu Hui described ways of measuringdistant objects in his work Haidao suanjing or The SeaIsland Mathematical Manual, published in 263 AD.The Romans recognized land surveyors as a profession.They established the basic measurements under which theRoman Empire was divided, such as a tax register of con-quered lands (300 AD).[3] Roman surveyors were known

1

2 2 HISTORY

as Gromatici.In medieval Europe, beating the bounds maintained theboundaries of a village or parish. This was the prac-tice of gathering a group of residents and walking aroundthe parish or village to establish a communal memory ofthe boundaries. Young boys were included to ensure thememory lasted as long as possible.In England, William the Conqueror commissioned theDomesday Book in 1086. It recorded the names of allthe land owners, the area of land they owned, the qualityof the land, and specic information of the areas contentand inhabitants. It did not include maps showing exactlocations.

2.2 Modern surveying

Abel Foullon described a plane table in 1551, but it isthought that the instrument was in use earlier as his de-scription is of a developed instrument.Gunters chain was introduced in 1620 by English math-ematician Edmund Gunter. It enabled plots of land to beaccurately surveyed and plotted for legal and commercialpurposes.Leonard Digges described a Theodolite that measuredhorizontal angles in his book A geometric practice namedPantometria (1571). Joshua Habermel (de:ErasmusHabermehl) created a theodolite with a compass and tri-pod in 1576. Johnathon Sission was the rst to incorpo-rate a telescope on a theodolite in 1725.[4]

In the 18th century, modern techniques and instrumentsfor surveying began to be used. Jesse Ramsden intro-duced the rst precision theodolite in 1787. It was aninstrument for measuring angles in the horizontal and ver-tical planes. He created his great theodolite using anaccurate dividing engine of his own design. Ramsdenstheodolite represented a great step forward in the instru-ments accuracy. William Gascoigne invented an instru-ment that used a telescope with an installed crosshair as atarget device, in 1640. James Watt developed an opticalmeter for the measuring of distance in 1771; it measuredthe parallactic angle from which the distance to a pointcould be deduced.Dutch mathematician Willebrord Snellius (a.k.a. Snell)introduced the modern systematic use of triangulation. In1615 he surveyed the distance from Alkmaar to Bergenop Zoom, approximately 70 miles (110 kilometres). Thesurvey was a chain of quadrangles containing 33 trianglesin all. Snell showed how planar formulae could be cor-rected to allow for the curvature of the earth. He alsoshowed how to resection, or calculate, the position of apoint inside a triangle using the angles cast between thevertices at the unknown point. These could be measuredmore accurately than bearings of the vertices, which de-pended on a compass. His work established the idea ofsurveying a primary network of control points, and lo-

cating subsidiary points inside the primary network later.Between 1733 and 1740, Jacques Cassini and his sonCsar undertook the rst triangulation of France. Theyincluded a re-surveying of the meridian arc, leading to thepublication in 1745 of the rst map of France constructedon rigorous principles. By this time, triangulation meth-ods were by then well established for local map-making,It was only towards the end of the 18th century that de-tailed triangulation network surveys mapped whole coun-tries. In 1784, a team from General William Roy'sOrdnance Survey of Great Britain began the PrincipalTriangulation of Britain. The rst Ramsden theodolitewas built for this survey. The survey was nally com-pleted in 1853. The Great Trigonometric Survey of Indiabegan in 1801. The Indian survey had an enormous sci-entic impact. It was responsible for one of the rst accu-rate measurements of a section of an arc of longitude, andfor measurements of the geodesic anomaly. It named andmapped Mount Everest and the other Himalayan peaks.Surveying became a professional occupation in high de-mand at the turn of the 19th century with the onset of theIndustrial Revolution. The profession developed moreaccurate instruments to aid its work. Industrial infras-tructure projects used surveyors to lay out canals, roadsand rail,In the US, the Land Ordinance of 1785 created the PublicLand Survey System. It formed the basis for dividing thewestern territories into sections to allow the sale of land.The PLSS divided states into township grids which werefurther divided into sections and fractions of sections.Napoleon Bonaparte founded continental Europe's rstcadastre in 1808. This gathered data on the number ofparcels of land, their value, land usage, and names. Thissystem soon spread around Europe.Robert Torrens introduced the Torrens system in SouthAustralia in 1858. Torrens intended to simplify landtransactions and provide reliable titles via a centralizedregister of land. The Torrens system was adopted in sev-eral other nations of the English-speaking world.

2.3 20th century

At the beginning of the century surveyors had improvedthe older chains and ropes, but still faced the problemof accurate measurement of long distances. Dr TrevorLloyd Wadley developed the Tellurometer during the1950s. It measures long distances using two microwavetransmitter/receivers.[5] During the late 1950s Geodime-ter introduced electronic distance measurement (EDM)equipment.[6] EDM units use a multi frequency phaseshift of light waves to nd a distance.[7] These instrumentssaved the need for days or weeks of chain measurementby measuring between points kilometers apart in one go.Advances in electronics allowed miniaturization of EDM.In the 1970s the rst instruments combining angle and

3distance measurement appeared, becoming known astotal stations. Manufacturers added more equipment bydegrees, bringing improvements in accuracy and speed ofmeasurement. Major advances include tilt compensators,data recorders, and on-board calculation programs.The rst Satellite positioning system was the US NavyTRANSIT system. The rst successful launch took placein 1960. The systems main purpose was to provide posi-tion information to Polaris missile submarines. Surveyorsfound they could use eld receivers to determine the loca-tion of a point. Sparse satellite cover and large equipmentmade observations laborious, and inaccurate. The mainuse was establishing benchmarks in remote locations.The US Air force launched the rst prototype satellitesof the Global Positioning System (GPS) in 1978. GPSused a larger constellation of satellites and improved sig-nal transmission to provide more accuracy. Early GPSobservations required several hours of observations by astatic receiver to reach survey accuracy requirements. Re-cent improvements to both satellites and receivers allowReal Time Kinematic (RTK) surveying. RTK surveys gethigh-accuracy measurements by using a xed base stationand a second roving antenna. The position of the rovingantenna can be tracked it moves.

2.4 21st century

The theodolite, total station, and RTKGPS survey remainthe primary methods in use.Remote sensing and satellite imagery continue to improveand become cheaper, allowing more commonplace use.Prominent new technologies include three-dimensional(3D) scanning and use of lidar for topographical surveys.

3 Surveying equipment

Main category: Surveying instruments

Surveying Equipment. Clockwise from upper left:Optical Theodolite, Robotic total station, Optical level,RTK GPS Base station.

The main surveying instruments in use around the worldare the theodolite and steel band, the total station, thelevel and rod and surveying GPS systems. Most instru-ments screw onto a tripod when in use. Tape measuresare often used for measurement of smaller distances. 3Dscanners and various forms of aerial imagery are alsoused.The Theodolite is an instrument for the measurement ofangles. It uses two separate circles, protractors or alidadesto measure angles in the horizontal and the vertical plane.A telescope mounted on trunnions is aligned verticallywith the target object. The whole upper section rotatesfor horizontal alignment. The vertical circle measuresthe angle that the telescope makes against the vertical,known as the vertical angle. The horizontal circle usesan upper and lower plate. When beginning the survey,the surveyor points the instrument in a known direction(bearing), and clamps the lower plate in place. The in-strument can then rotate to measure the bearing to otherobjects. If no bearing is known or direct angle measure-ment is wanted, the instrument can be set to zero during

4 4 SURVEYING TECHNIQUES

the initial sight. It will then read the angle between theinitial object, the theodolite itself, and the item that thetelescope aligns with.The Gyrotheodolite is a form of theodolite that uses a gy-roscope to orient itself in the absence of reference marks.It is used in underground applications.The total station is a development of the theodolite withan electronic distance measurement device (EDM). A to-tal station can be used for leveling when set to the hori-zontal plane. Since their introduction, total stations haveshifted from optical-mechanical to fully electronic de-vices.Modern top-of-the-line total stations no longer need a re-ector or prism to return the light pulses used for dis-tance measurements. They are fully robotic, and caneven e-mail point data to a remote computer and con-nect to satellite positioning systems, such as Global Posi-tioning System. Real Time Kinematic GPS systems haveincreased the speed of surveying, but they are still onlyhorizontally accurate to about 20 mm and vertically to3040 mm.[8]

GPS surveying diers from other GPS users in the equip-ment and methods used. Static GPS uses two receiversplaced in position for a considerable length of time. Thelong span of time lets the receiver comparemeasurementsas the satellites orbit. The changes as the satellites orbitalso provide the measurement network with well condi-tioned geometry. This produces an accurate baseline thatcan be over 20 km long. RTK surveying uses one staticantenna and one roving antenna. The static antenna trackschanges in the satellite positions and atmospheric condi-tions. The surveyor uses the roving antenna to measurethe points needed for the survey. The two antennas usea radio link that allows the static antenna to send correc-tions to the roving antenna. The roving antenna then ap-plies those corrections to the GPS signals it is receiving tocalculate its own position. RTK surveying covers smallerdistances than static methods. This is because divergentconditions further away from the base reduce accuracy.Surveying instruments have characteristics that makethem suitable for certain uses. Theodolites and levels areoften used by constructors rather than surveyors in rstworld countries. The constructor can perform simple sur-vey tasks using a relatively cheap instrument. Total sta-tions are workhorses for many professional surveyors be-cause they are versatile and reliable in all conditions. Theproductivity improvements from aGPS on large scale sur-veys makes them popular for major infrastructure or datagathering projects. One-person robotic-guided total sta-tions allow surveyors to measure without extra workersto aim the telescope or record data. A fast but expensiveway to measure large areas is with a helicopter, using aGPS to record the location of the helicopter and a laserscanner to measure the ground. To increase precision,surveyors place beacons on the ground (about 20 km (12mi) apart). This method reaches precisions between 540

cm (depending on ight height).[9]

Surveyors use ancillary equipment such as: tripods andinstrument stands; staves and beacons used for sightingpurposes; PPE; vegetation clearing equipment; diggingimplements for nding survey markers buried over time;hammers for placements of markers in various surfacesand structures; and portable radios for communicationover long lines of sight.

4 Surveying techniquesSurveyors determine the position of objects by measuringangles and distances. The factors that can aect the accu-racy of their observations are also measured. They thenuse this data to create vectors, bearings, co-ordinates, el-evations, areas, volumes, plans and maps. Measurementsare often split into horizontal and vertical components tosimplify calculation. GPS and astronomic measurementsalso need measurement of a time component.

4.1 Distance measurement

Before EDM devices, distances were measured using avariety of means. These included chains having links ofa known length such as a Gunters chain, or measuringtapes made of steel or invar. To measure horizontal dis-tances, these chains or tapes were pulled taut to reducesagging and slack. The distance had to be adjusted forheat expansion. Attempts to hold the measuring instru-ment level would also be made. When measuring up aslope, the surveyor might have to break (break chain)the measurement- use an increment less than the totallength of the chain. Perambulators, or measuring wheels,were used to measure longer distances but not to a highlevel of accuracy. Tacheometry is the science of measur-ing distances by measuring the angle between two ends ofan object with a known size. It was sometimes used be-fore to the invention of EDM where rough ground madechain measurement impractical.

4.2 Angle measurement

Historically, horizontal angles were measured by usinga compass to provide a magnetic bearing. The deec-tion from the bearing was recorded. Later, more pre-cise scribed discs later improved better angular resolu-tion. Mounting telescopes with reticles atop the disc al-lowed more precise sighting. (see theodolite). Levels andcalibrated circles allowedmeasurement of vertical angles.verniers allowed measurement to a fraction of a degree,such as with a turn-of-the-century transit.The Plane table provided a graphical method of record-ing and measuring angles, which reduced the amount ofmathematics required.

4.5 Reference networks 5

By observing the bearing from every vertex in a gure, asurveyor can measure around the gure. The nal obser-vation will be between the two points rst observed, ex-cept with a 180 dierence. This is called a close. If therst and last bearings are dierent, this shows the errorin the survey, called the angular misclose. The surveyorcan use this information to prove that the work meets theexpected standards.

4.3 Levelling

Main article: LevellingThe simplest method for measuring height is with analtimeter using air pressure to nd height. When moreprecise measurements are needed, means like precise lev-els (also known as dierential leveling) are used. Whenprecise leveling, a series of measurements between twopoints are taken using an instrument and a measuringrod. Dierences in height between the measurementsare added and subtracted in a series to get the net dif-ference in elevation between the two endpoints. With theGlobal Positioning System (GPS), elevation can be mea-sured with satellite receivers. Usually GPS is somewhatless accurate than traditional precise leveling, but may besimilar over long distances.When using an optical level, the endpoint may be out ofthe eective range of the instrument. There may be ob-structions or large changes of elevation between the end-points. In these situations, extra setups are needed. Turn-ing is a term used when referring to moving the level totake an elevation shot from a dierent location. To turnthe level, one must rst take a reading and record the ele-vation of the point the rod is located on. While the rod isbeing kept in exactly the same location, the level is movedto a new location where the rod is still visible. A readingis taken from the new location of the level and the heightdierence is used to nd the new elevation of the levelgun. This is repeated until the series of measurementsis completed. The level must be horizontal to get a validmeasurement. Because of this, if the horizontal crosshairof the instrument is lower than the base of the rod, thesurveyor will not be able to sight the rod and get a read-ing. The rod can usually be raised up to 25 feet high,allowing the level to be set much higher than the base ofthe rod.

4.4 Determining position

The primary way of determining ones position on theearths surface when no known positions are nearby is byastronomic observations. Observations to the sun, moonand stars could all be made using navigational techniques.Once the instruments position and bearing to a star isdetermined, the bearing can be transferred to a refer-ence point on the earth. The point can then be used asa base for further observations. Survey-accurate astro-

nomic positions were dicult to observe and calculateand so tended to be a base o which many other measure-ments were made. Since the advent of the GPS system,astronomic observations are rare as GPS allows adequatepositions to be determined over most of the surface of theearth.

4.5 Reference networks

Main article: Geodetic networkFew survey positions are derived from rst principles.Instead, most surveys points are measured relative to pre-vious measured points. This forms a reference or controlnetwork where each point can be used by a surveyor todetermine their own position when beginning a new sur-vey.Survey points are usually marked on the earths surface byobjects ranging from small nails driven into the ground tolarge beacons that can be seen from long distances. Thesurveyors can set up their instruments on this position andmeasure to nearby objects. Sometimes a tall, distinctivefeature such as a steeple or radio aerial has its position cal-culated as a reference point that angles can be measuredagainst.Triangulation is a method of horizontal location favouredin the days before EDM and GPS measurement. It candetermine distances, elevations and directions betweendistant objects. Since the early days of surveying, this wasthe primary method of determining accurate positions ofobjects for topographic maps of large areas. A surveyorrst needs to know the horizontal distance between twoof the objects, known as the baseline. Then the heights,distances and angular position of other objects can be de-rived, as long as they are visible from one of the originalobjects. High-accuracy transits or theodolites were used,and angle measurements repeated for increased accuracy.See also Triangulation in three dimensions.Osetting is an alternate method of determining positionof objects, and was often used to measure imprecise fea-tures such as riverbanks. The surveyor would mark andmeasure two known positions on the ground roughly par-allel to the feature, andmark out a baseline between them.At regular intervals, a distance was measured at right an-gles from the rst line to the feature. The measurementscould then be plotted on a plan or map, and the points atthe ends of the oset lines could be joined to show thefeature.Traversing is a common method of surveying smaller ar-eas. The surveyor starts from an old reference mark orknown position and places a network of reference markscovering the survey area. They thenmeasure bearings anddistances between the reference marks, and to the targetfeatures. Most traverses form a loop pattern or link be-tween two prior reference marks to allow the surveyor tocheck their measurements are correct.

6 5 TYPES OF SURVEYS

4.5.1 Datum and coordinate systems

Many surveys do not calculate positions on the surface ofthe earth, but instead measure the relative positions of ob-jects. However, often the surveyed items need to be com-pared to outside data, such as boundary lines or previoussurveys objects. The oldest way of describing a positionis via latitude and longitude, and often a height above sealevel. As the surveying profession grew it created Carte-sian coordinate systems to simplify the mathematics forsurveys over small parts of the earth. The simplest coor-dinate systems assume that the earth is at and measurefrom an arbitrary point, known as a 'datum' (singular formof data). The coordinate system allows easy calculationof the distances and direction between objects over smallareas. Large areas distort due to the earths curvature.North is often dened as true north at the datum.For larger regions, it is necessary to model the shape ofthe earth using an ellipsoid or a geoid. Many countrieshave created coordinate-grids customized to lessen errorin their area of the earth.

4.6 Errors and accuracy

A basic tenet of surveying is that no measurement is per-fect, and that there will always be a small amount oferror.[10] There are three classes of survey errors:

Gross errors or blunders: Errors made by the sur-veyor during the survey. Upsetting the instrument,misaiming a target, or writing down a wrong mea-surement are all gross errors. A large gross errormay reduce the accuracy to an unacceptable level.Therefore surveyors use redundant measurementsand independent checks to detect these errors earlyin the survey.

Systematic: Errors that follow a consistent pattern.Examples include eects of temperature on a chainor EDM measurement, or a poorly adjusted spirit-level causing a tilted instrument or target pole. Sys-tematic errors that have known eects can be com-pensated or corrected.

Random: Random errors are small unavoidable uc-tuations. They are caused by imperfections in mea-suring equipment, eyesight, and conditions. Theycan be minimized by redundancy of measurementand avoiding unstable conditions. Random errorstend to cancel each other out, but checks must bemade to ensure they are not propagating from onemeasurement to the next.

Surveyors avoid these errors by regular checks on theirequipment, using consistent methods, and by good de-sign of their reference network. Redundancy of mea-surements allows the use of averaging and allows outlier

measurements to be discarded. Independent checks likemeasuring a point from two or more locations or usingtwo dierent methods are used. Errors can be detectedby comparing the results of the two measurements.Once the surveyor has calculated the level of the errors inhis work, it is adjusted. This is the process of distributingthe error between all measurements. Each observation isweighted according to how much of the total error it islikely to have caused and part of that error is allocated toit in a proportional way. The most common methods ofadjustment are the Bowditch method, also known as thecompass rule, and the Principle of least squares method.The Surveyor must be able to distinguish betweenaccuracy and precision. In the United States, surveyorsand civil engineers use units of feet wherein a survey footbreaks down into 10ths and 100ths. Many deed descrip-tions containing distances are often expressed using theseunits (125.25 ft). On the subject of accuracy, surveyorsare often held to a standard of one one-hundredth of afoot; about 1/8 inch. Calculation and mapping tolerancesare much smaller wherein achieving near-perfect closuresare desired. Though tolerances will vary from project toproject, in the eld and day to day usage beyond a 100thof a foot is often impractical.

5 Types of surveysSee also: Survey (disambiguation) and Survey Earthsciences

Local professional organisation or regulatory bodies clas-sify specializations of surveying in dierent ways. Broadgroups are:

As-built survey: a survey that documents the loca-tion of recently constructed elements of a construc-tion project. Asbuilt surveys are done for record,completion evaluation and payment purposes. Anas-built survey is also known as a 'works as executedsurvey'. As built surveys are often presented in redor redline and laid over existing plans for compari-son with design information.

Cadastral or boundary surveying: a survey that es-tablishes or re-establishes boundaries of a parcel us-ing a legal description. It involves the setting orrestoration of monuments or markers at the cornersor along the lines of the parcel. These take theform of iron rods, pipes, or concrete monumentsin the ground, or nails set in concrete or asphalt.The ALTA/ACSM Land Title Survey is a standardproposed by the American Land Title Associationand the American Congress on Surveying and Map-ping. It incorporates elements of the boundary sur-vey, mortgage survey, and topographic survey.

7 Control surveying: Control surveys establish refer-ence points to use as starting positions for futuresurveys. Most other forms of surveying will containelements of control surveying.

Construction surveying Deformation survey: a survey to determine if astructure or object is changing shape or moving.First the positions of points on an object are found.A period of time is allowed to pass and the positionsare then re-measured and calculated. Then a com-parison between the two sets of positions is made.

Dimensional control survey: This is a type of surveyconducted in or on an non-level surface. Commonin the oil and gas industry to replace old or damagedpipes on a like-for-like basis. The advantage of di-mensional control survey is that the instrument usedto conduct the survey does not need to be level. Thisis useful in the o-shore industry, as not all plat-forms are xed and are thus subject to movement.

Engineering surveying: topographic, layout, and as-built surveys associated with engineering design.They often need geodetic computations beyond nor-mal civil engineering practice.

Foundation survey: a survey done to collect the posi-tional data on a foundation that has been poured andis cured. This is done to ensure that the foundationwas constructed in the location, and at the elevation,authorized in the plot plan, site plan, or subdivisionplan.

Hydrographic survey: a survey conducted with thepurpose of mapping the shoreline and bed of a bodyof water. Used for navigation, engineering, or re-source management purposes.

Leveling: either nds the elevation of a given pointor establish a point at a given elevation.

LOMA survey: Survey to change base ood line, re-moving property from a SFHA special ood hazardarea.

Measured survey : a building survey to produce plansof the building. such a survey may be conductedbefore renovation works, for commercial purpose,or at end of the construction process.

Mining surveying: Mining surveying includes direct-ing the digging of mine shafts and galleries and thecalculation of volume of rock. It uses specialisedtechniques due to the restraints to survey geometrysuch as vertical shafts and narrow passages.

Mortgage survey: Amortgage survey or physical sur-vey is a simple survey that delineates land boundariesand building locations. It checks for encroachment,building setback restrictions and shows nearby ood

zones. In many places a mortgage survey is a pre-condition for a mortgage loan.

Photographic control survey: A survey that createsreference marks visible from the air to allow aerialphotographs to be rectied.

Stakeout, Layout or Setout: an element ofmany othersurveys where the calculated or proposed position ofan object is marked on the ground. This can be tem-porary or permanent. This is an important compo-nent of engineering and cadastral surveying.

Structural survey: a detailed inspection to reportupon the physical condition and structural stabilityof a building or structure. It highlights any workneeded to maintain it in good repair.

Subdivision: A boundary survey that splits a propertyinto two or more smaller properties.

Topographic survey: a survey that measures the el-evation of points on a particular piece of land, andpresents them as contour lines on a plot.

6 The surveying professionSee also: GeomaticsThe basic principles of surveying have changed little overthe ages, but the tools used by surveyors have evolved.Engineering, especially civil engineering, often needssurveyors.Surveyors help determine the placement of roads,railways, reservoirs, dams, pipelines, retaining walls,bridges, and buildings. They establish the boundaries oflegal descriptions and political divisions. They also pro-vide advice and data for geographical information systems(GIS) that record land features and boundaries.Surveyors must have a thorough knowledge of algebra,basic calculus, geometry, and trigonometry. They mustalso know the laws that deal with surveys, real property,and contracts.Most jurisdictions recognize three dierent levels ofqualication:Survey assistants or chainmen are usually unskilled work-ers who help the surveyor. They place target reectors,nd old reference marks, and mark points on the ground.The term 'chainman' derives from past use of measuringchains. An assistant would move the far end of the chainunder the surveyors direction.Survey technicians often operate survey instruments, runsurveys in the eld, do survey calculations, or draft plans.A technician usually has no legal authority and cannotcertify his work. Not all tehnicians are qualied, but qual-ications at the certicate or diploma level are available.

8 6 THE SURVEYING PROFESSION

Licensed, registered, or chartered surveyors usually holda degree or higher qualication. They are often requiredto pass further exams to join a professional associationor to gain certifying status. Surveyors are responsible forplanning and management of surveys. They have to en-sure that their surveys, or surveys performed under theirsupervision, meet the legal standards. Many principals ofsurveying rms hold this status.

6.1 Informal surveying

Not all surveys are carried out by professional survey-ors. Depending on the jurisdiction and circumstances,the builders of a structure may set it out themselves. Sur-veyors often set out the most signicant corners of abuilding. The builders then lay out the rest of the buildingthemselves simple survey techniques.

6.2 Licensing

Licensing requirements vary with jurisdiction, and arecommonly consistent within national borders.

6.2.1 United States

Most of the US recognizes surveying as a distinct profes-sion apart from engineering.Licensing requirements vary by state, but they havecomponents of education, experience, and examina-tions. Most states insist upon the basic qualicationof a degree in surveying, plus experience and examina-tion requirements. In the past, candidates completed anapprenticeship before taking a series of examinations togain licensure.The licensing process follows two phases. Upon gradu-ation, the candidate may take the Fundamentals of Sur-veying (FS) exam. If they pass and meet the other re-quirements they become a surveying intern (SI). Uponcertication as an SI, the candidate then needs to gainon-the-job experience to become eligible for the secondphase. In most states, this is the Principles and Practice ofLand Surveying (PS) exam and a state-specic examina-tion. SIs were formerly called surveyors in training (SIT).Licensed surveyors usually denote themselves with postnominals. The letters PLS (professional land surveyor),PS (professional surveyor), LS (land surveyor), RLS (reg-istered land surveyor), RPLS (Registered ProfessionalLand Surveyor), or PSM(professional surveyor and map-per) follow their names, depending upon their jurisdictionof registration.

6.2.2 Canada

See also: Geomatics engineering

In Canada, land surveyors register to work in their respec-tive province. The designation for a land surveyor breaksdown by province. It follows the rule whereby the rst let-ter indicates the province, followed by L.S. There is also adesignation C.L.S. or Canada lands surveyor. They havethe authority to work on Canada lands, which include In-dian Reserves, National Parks, the three territories, andoshore lands.

6.2.3 Commonwealth

Many Commonwealth countries use the term CharteredLand Surveyor for someone holding a professional li-cense.

6.2.4 Legal aspects

A licensed land surveyor is generally required to sign andseal all plans. The state dictates the format, showing theirname and registration number.In many jurisdictions, surveyors must mark their registra-tion number on surveymonuments when setting boundarycorners. Monuments take the form of capped iron rods,concrete monuments, or nails with washers.

6.3 Surveying institutions

Most countries governments regulate at least some formsof surveying. Their survey agencies establish regulationsand standards. Standards control accuracy, surveying cre-dentials, monumentation of boundaries and maintenanceof geodetic networks. Many nations devolve this author-ity to regional entities or states/provinces. Cadastral sur-veys tend to be the most regulated because of the perma-nence of the work. Lot boundaries established by cadas-tral surveysmay stand for hundreds of years without mod-ication.Most jurisdictions also have a form of professional in-stitution representing local surveyors. These institutesoften endorse or license potential surveyors, as well asset and enforce ethical standards. The largest institutionis the International Federation of Surveyors (Abbrevi-ated FIG, for French: Fdration Internationale des Go-mtres). They represent the survey industry worldwide.

6.4 Building surveying

Main article: Building surveying Profession

9Most English-speaking countries consider building sur-veying a distinct profession. They have their own profes-sional associations and licencing requirements. Buildingsurveyors focus on investigating the condition of build-ings as well as legal compliance work.

6.5 Cadastral surveyingMain article: Cadastral surveying

One of the primary roles of the land surveyor is to deter-mine the boundary of real property on the ground. Thesurveyor must determine where the adjoining landownerswish to put the boundary. The boundary is established inlegal documents and plans prepared by attorneys, engi-neers, and land surveyors. The surveyor then puts mon-uments on the corners of the new boundary. They mightalso nd or resurvey the corners of the property monu-mented by prior surveys.Cadastral land surveyors are licensed by governments.The cadastral survey branch of the Bureau of LandManagement (BLM) conducts most cadastral surveys inthe United States.[11] They consult with Forest Service,National Park Service, Army Corps of Engineers, Bureauof Indian Aairs, Fish and Wildlife Service, Bureau ofReclamation, and others. The BLM used to be known asthe General Land Oce (GLO).In states organized per the Public Land Survey System(PLSS), surveyors must carry out BLM cadastral surveysunder that system.Cadastral surveyors often have to work around changes tothe earth that obliterate or damage boundary monuments.When this happens, they must consider evidence that isnot recorded on the title deed. This is known as extrinsicevidence.[12]

7 See also Adjustments of theodolites Cartography International Federation of Surveyors Land surveying software Primary divisions of Surveying Prismatic compass (surveying) Surveying in early America

8 References[1] Johnson, Anthony, Solving Stonehenge: The New Key to an

Ancient Enigma. (Thames & Hudson, 2008) ISBN 978-

0-500-05155-9

[2] Hong-Sen Yan & Marco Ceccarelli (2009), InternationalSymposium on History of Machines and Mechanisms: Pro-ceedings of HMM 2008, Springer, p. 107, ISBN 1-4020-9484-1

[3] Lewis, M. J. T. (2001-04-23). Surveying Instruments ofGreece and Rome. Cambridge University Press. ISBN9780521792974. Retrieved 30 August 2012.

[4] Turner, Gerard L'E. Nineteenth Century Scientic Instru-ments, Sotheby Publications, 1983, ISBN 0-85667-170-3

[5] Sturman, Brian; Wright, Alan. The History of theTellurometer (PDF). http://www.fig.net/''. InternationalFederation of Surveyors. Retrieved 20 July 2014.

[6] Cheves, Marc. Geodimeter-The First Name in EDM.http://www.profsurv.com/magazine/''. Retrieved 2014-07-20.

[7] Mahun, Jerry. Electronic Distance Measurement. Jer-rymahun.com. Retrieved 2014-07-20.

[8] National Cooperative Highway Research Program: Col-lecting, Processing and Integrating GPS data into GIS, p.40. Published by Transportation Research Board, 2002ISBN 0-309-06916-5, ISBN 978-0-309-06916-8

[9] Toni Schenk, Suyoung Seo, Beata Csatho: Accuracy Studyof Airborne Laser Scanning Data with Photogrammetry, p.118

[10] Kahmen, Heribert; Faig, Wolfgang (1988). Surveying.Berlin: de Gruyter. p. 9. ISBN 3-11-008303-5. Re-trieved 2014-08-10.

[11] A History of the Rectangular Survey System by C. AlbertWhite, 1983, Pub: Washington, D.C. : U.S. Dept. of theInterior, Bureau of Land Management : For sale by Supt.of Docs., U.S. G.P.O.,

[12] Richards, D., & Hermansen, K. (1995). Use of extrinsicevidence to aid interpretation of deeds. Journal of Sur-veying Engineering, (121), 178.

9 Further reading The Surveying Handbook. 1995.doi:10.1007/978-1-4615-2067-2. ISBN 978-1-4613-5858-9.

Keay J (2000), The Great Arc: The Dramatic Taleof How India was Mapped and Everest was Named,Harper Collins, 182pp, ISBN 0-00-653123-7.

Pugh J C (1975), Surveying for Field Scientists,Methuen, 230pp, ISBN 0-416-07530-4

Genovese I (2005), Denitions of Surveying and As-sociated Terms, ACSM, 314pp, ISBN 0-9765991-0-4.

10 10 EXTERNAL LINKS

Public Land Survey System Foundation (2009)Manual of Surveying Instructions For the Surveyof the Public Lands of the United States. www.blmsurveymanual.org

10 External links Gomtres sans Frontires : Association de gome-tres pour aide au dveloppement. NGO Surveyorswithout borders (French)

The National Museum of Surveying The Home ofthe National Museum of Surveying in Springeld,Illinois

Land Surveyors United Support Network Global so-cial support network featuring surveyor forums, in-structional videos, industry news and support groupsbased on geolocation.

Natural Resources Canada Surveying Goodoverview of surveying with references to con-struction surveys, cadastral surveys, photogramme-try surveys, mining surveys, hydrographic surveys,route surveys, control surveys and topographic sur-veys

As-builts - Problems& Proposed SolutionsDis-cussion on Building Surveys within Construction in-dustry by Stephen R. Pettee, CCM

Table of Surveying, 1728 Cyclopaedia Google Map with overlays for principal meridians,coordinate zones, NGS Control, USGS topographicmaps and more

Surveying & Triangulation The History Of Survey-ing And Survey Equipment

BASIC programs for surveying and mapping NCEES National Council of Examiners for Engi-neering and Surveying (NCEES)

RICS Certied RICS Certied Surveyors in MiddleEast and North Africa(Land Sterling)

A plumb rule from the book Cassells Carpentry and Joinery

11

Table of Surveying, 1728 Cyclopaedia

A map of India showing the Great Trigonometrical Survey, pro-duced in 1870

A German engineer surveying during the First World War, 1918

A standard Brunton Geo compass, still used commonly today bygeographers, geologists and surveyors for eld-based measure-ments

Example of modern equipment for surveying (Field-Map tech-nology): GPS, laser rangender and eld computer allows sur-veying as well as cartography (creation of map in real-time) andeld data collection.

12 10 EXTERNAL LINKS

Center for Operational Oceanographic Products and Servicessta member conducts tide station leveling in support of the USArmy Corp of Engineers in Richmond, Maine.

A survey using traverse and oset measurements to record thelocation of the shoreline shown in blue. Black dashed lines aretraverse measurements between reference points (black circles).The red lines are osets measured at right angles to the traverselines.

The pundit (explorer) cartographer Nain Singh Rawat (19th cen-tury) received a Royal Geographical Society gold medal in 1876,for his eorts in exploring the Himalayas for the British

An all-female surveying crew in Idaho, 1918

13

Surveying students with their professor at the Helsinki Universityof Technology in the late 19th century

F.V. Hayden's map of Yellowstone National Park, 1871. Hissurveys were a signicant basis for establishing the park in 1872.

14 11 TEXT AND IMAGE SOURCES, CONTRIBUTORS, AND LICENSES

11 Text and image sources, contributors, and licenses11.1 Text

Surveying Source: http://en.wikipedia.org/wiki/Surveying?oldid=664836228 Contributors: Fredbauder, PierreAbbat, Heron, Rsabbatini,Patrick, Michael Hardy, Nixdorf, Wapcaplet, SebastianHelm, Tregoweth, Cherkash, GRAHAMUK, Dysprosia, Warofdreams, Shafei,Hadal, Xanzzibar, Cutler, Jpo, Giftlite, BenFrantzDale, Netoholic, Cantus, Skagedal, Mboverload, Bobblewik, LiDaobing, Quadell, Mza-jac, Icairns, Hugh Mason, Sonett72, Thorwald, Vermeer~enwiki, Mike Rosoft, D6, Geof, Sysy, Rhobite, Guanabot, Vsmith, Brian0918,Mikeh, Maurreen, Giraedata, Diceman, Darwinek, Rje, 3mta3, Clyde frogg, Hesperian, Polylerus, Pearle, Mdd, Arthena, Nealcard-well, Carbon Caryatid, Paleorthid, MarkGallagher, Bart133, Earpol, Jguk, Ceyockey, Brookie, Woohookitty, Natcase, PoccilScript, Com-mander Keane, JonH, JeremyA, DavidCane, BD2412, Josh Parris, Squideshi, Rjwilmsi, Koavf, Jake Wartenberg, Thon Brocket, RCSB,Graibeard, Krash, DirkvdM, Vuong Ngan Ha, FTIII, RJP, Morleyevans, RexNL, Ewlyahoocom, BMF81, MoRsE, CiaPan, Korg, Jimp,StuOfInterest, RussBot, Fabartus, Koeyahoo, YEvb0, Hydrargyrum, Lovesick, NawlinWiki, Gillis, Albedo, Malcolma, Elkman, Igif-n, Closedmouth, Petri Krohn, Sanyarajan, Kestenbaum, Chrishmt0423, Russhull, Aamrun, KNHaw, Roke, XieChengnuo, DVD R W,SmackBot, FishSpeaker, IddoGenuth, Zerida, McGeddon, Jagged 85, Tbonnie, Hardyplants, Gjs238, Gilliam, Dyvroeth, Durova, Schmit-eye, Saros136, Chris the speller, Rajeevmass~enwiki, EncMstr, Dlohcierekims sock, Aquarius Rising, Quigabyte, Midnightcomm, HoofHearted, Dreadstar, ShaunES, David G. Smith, Fuzzypeg, Cronholm144, Bensontrent, Rijkbenik, Dumelow, Peterlewis, 16@r, Grumpyy-oungman01, Viv Hamilton, Geologyguy, Peter Horn, Stuartralston, DouglasCalvert, Fan-1967, Anger22, JForget, BoH, N2e, Neelix, Cy-debot, Alvesgaspar, Doug Weller, Lonny~enwiki, Lindsay658, S Marshall, Rsieg, Kylests, Sobreira, John254, Gerry Ashton, Turkeyphant,Floridasand, Dawnseeker2000, Hydryad, Gioto, Seaphoto, Mooksas, Fayenatic london, Glasnt, 1Rabid Monkey, JAnDbot, Wikifriendpt001, Magioladitis, Bongwarrior, AuburnPilot, Pixie2000, Allstarecho, LorenzoB, Vssun, Bramfab, MartinBot, Francis Tyers, Leon II,Zen-in, Michael Daly, Zuejay, McSly, Surveyingdealer, Il cacciatore, Sanscrit1234, Mermadak, Mysterious BIG, KylieTastic, DeltaOp-erator, Robertknyc, CindyBo, Je G., Dirtworker444, Sagaraf, Spudtu, Markusbela, Philip Trueman, Ltvine, Someguy1221, Steven J.Anderson, Setreset, Badly Bradley, Seanfour, JamesJereys, Cbrek04, Poltair, Jd4x4, SalomonCeb, Insanity Incarnate, Scarian, Struem-per, Phasedrifter101, Adam.hyde, Flyer22, Sander1453, JuanFox, Webschem, BFlynn301, Miniapolis, Lightmouse, Davidmmcfadden,Dmurfey, Apathyisboring, Moeng, Afterbrunel, ZULKARNAINI, Dolphin51, Denisarona, Geometricks, Martarius, ClueBot, Abcarb,TripleThree, TrigWorks, Mild Bill Hiccup, Ramakrishna.y, J8079s, Piledhigheranddeeper, S Karki, Jusdafax, The amingo, Eeekster,Heroicjake, Sun Creator, Verwol, Arjayay, Iohannes Animosus, Razorame, Dekisugi, Blargh2015, Thingg, LukeStewart, DerBorg, Ver-sus22, Scooter171, Skunkboy74, XLinkBot, Fastily, Rror, Q247, Noctibus, RP459, Kbdankbot, Addbot, Mr0t1633, Cogorman, Histo01,Brooski, Haruth, Ucla90024, Fgnievinski, Kennyxmas, SpellingBot, Ronhjones, Moglucy, Misterx2000, NjardarBot, MrOllie, Glane23,LarryJe, Cesiumfrog, Scottpolie, JSR, Hartz, Ale66, Sitehut, Yobot, 2D, Marcbela, Bunnyhop11, Fraggle81, TaBOT-zerem, J de-mers17, DisillusionedBitterAndKnackered, AnomieBOT, Materialscientist, Timaar31, Neurolysis, Crystallistica, NSK Nikolaos S. Karas-tathis, The sock that should not be, 4twenty42o, Axan.bulut, Anna Frodesiak, Turk olan, RibotBOT, AlexPlante, Shadowjams, Erik9bot,A.amitkumar, FrescoBot, Jc3s5h, Mikrosha, Dil.dilshan, DrilBot, Pinethicket, Codemister13, Whatever2009, RedBot, SpaceFlight89, Pb-southwood, Fama Clamosa, DARTH SIDIOUS 2, Helloher, Schrockg, , JPS31, EmausBot, John of Reading, Hydrographicaljobs,Immunize, ExilorX, Ebe123, Uvmcdi, F, Jaydiem, Bldrjn, A930913, Thomaserowe, Tamzid planner, Noodleki, 28bot, -revi, Paddy158,ClueBot NG, JenniDahl, Landsurveyorsunited, Mattp87, 7891joey, Gbreisch, Cheers!, Laezarb, Widr, HarnessTech, Reify-tech, Lawson-stu, Helpful Pixie Bot, HMSSolent, History74, BG19bot, Fjbm, AvocatoBot, Idouglas1304, TBP25, Johns334, Dbriggs1982, BattyBot,Land Surveyor, Meb23-NJITWILL, Pratyya Ghosh, Simoteho, Kamyia3000, Khazar2, Kevmeister68, Lugia2453, Angusta, Betaville,Scott Warner, Tentinator, Flat Out, My name is not dave, Quenhitran, Jianhui67, ThisWillBlowRichsMind, Bobmodikiw, Kelvinmike09,Jellermine, Scott sanderson1989, Owais Khursheed, Walnut99, Muazim Balwan, Kelvinmike08, Mndata, Peter Tapken and Anonymous:428

11.2 Images File:1870_Index_Chart_to_GTS_India-1.jpg Source: http://upload.wikimedia.org/wikipedia/commons/0/00/1870_Index_Chart_to_

GTS_India-1.jpg License: Public domain Contributors: Survey of India Original artist: Survey of India File:All_female_survey_crew_-_Minidoka_Project,_Idaho_1918.jpg Source: http://upload.wikimedia.org/wikipedia/commons/f/f3/

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11.3 Content license Creative Commons Attribution-Share Alike 3.0

ACSM definitionsHistoryAncient surveyingModern surveying20th century21st century

Surveying equipmentSurveying techniquesDistance measurementAngle measurementLevellingDetermining positionReference networksDatum and coordinate systems

Errors and accuracy

Types of surveysThe surveying profession Informal surveyingLicensing United StatesCanadaCommonwealthLegal aspects

Surveying institutionsBuilding surveyingCadastral surveying

See alsoReferences Further readingExternal linksText and image sources, contributors, and licensesTextImagesContent license