Technical English - I

5th week

SURVEYING AND MAPPING

surveying / position / natural / man made / feature / equipment / mapping

What is surveying?What is surveying?

It is the art of defining the positions of natural It is the art of defining the positions of natural

and manand man--made features on the Earth’s surface. made features on the Earth’s surface.

Basic Tasks and Features in SurveyingBasic Tasks and Features in Surveying::

�� MeasurementsMeasurements

�� Surveying tools and equipmentSurveying tools and equipment

�� Evaluation of survey data Evaluation of survey data

�� Mapping Mapping

distance / elevation / angle / coordinates

Basic Engineering measurements:Basic Engineering measurements:�� DistanceDistance

�� ElevationElevation

�� AngleAngle

�� Coordinates (X/Y or Lat/Long etc.)Coordinates (X/Y or Lat/Long etc.)

distancedistance ≈

intervalinterval

lengthlength

spacespace

Elevation (vertical Elevation (vertical

position) is the height position) is the height

of a point relative to of a point relative to

some reference pointsome reference point

Today’s Engineering Survey TasksToday’s Engineering Survey Tasks

� Cadastral surveying

� Area calculations

� Complex volume calculations

� Stockpile surveys

� Cut / excavation / fill calculations (Surveying for landfill sites)

� Slope measurements

� Cross and long sections

� Aerial photography surveying (photogrammetric survey)

� Surveying for 3D model generation

Building Measurements and Structural Monitoring Building Measurements and Structural Monitoring

� Setting out of buildings (building footprint)

� Facade measurements

� Deformation / settlement monitoring, inspection measurements

� Underground utility mapping survey

cadastral / stockpile / excavation / photogrammetry / generation / facade / utility/ building setting out / footprint / deformation / monitoring / settlement / inspection

surveying tools / equipment / device / traditional / contemporary / state-of-the-art

Traditional and contemporary (stateTraditional and contemporary (state--ofof--

thethe--art electronic devices) surveying toolsart electronic devices) surveying tools

steel tape / chaining pins / spring tension / compass / optical square / ranging rodsflag-pole / staff / theodolite / transit / total station / level / tripod

steel tapes steel tapes

spring tensionspring tension

theodolitetheodolite

compasscompass

ranging rods & flagranging rods & flag--polepole

optical squareoptical square

chaining pinschaining pins

tripodtripod

staffstaff

levellevel

Tripods are used for Tripods are used for

several surveying several surveying

instruments, such instruments, such

asas theodolitestheodolites, total , total

stations,stations, levelslevels or or

transits.transits.

transittransit

They are the same thing. Europeans tend to say They are the same thing. Europeans tend to say

""theodolitetheodolite", which is the older term. Americans tend to ", which is the older term. Americans tend to

say "transit."say "transit." BothBoth theodolitestheodolites and transits are and transits are

instruments used by surveyors to measure horizontal instruments used by surveyors to measure horizontal

and vertical angles, measure distances and determine and vertical angles, measure distances and determine

elevations. Generally aelevations. Generally a theodolitetheodolite is moreis more precise in precise in

point of point of verniervernier increments and optical systems. It increments and optical systems. It

hashas more more incrementationsincrementations on the circle. on the circle.

theodolitetheodolite

verniervernier increments increments

theodolite / transit / total station / instrument / precise / vernier / optics

What is the difference between a What is the difference between a theodolitetheodolite

and a transit?and a transit?

The original The original theodolitetheodolite was a was a

purely optical instrument, but purely optical instrument, but

nowadays most nowadays most theodolitestheodolites

come with an electronic come with an electronic

distancedistance--measuring attachment measuring attachment

called as total station. Total called as total station. Total

stations possess automatic stations possess automatic

angle and distance readout angle and distance readout

capabilities.capabilities.

What is the difference between a What is the difference between a theodolitetheodolite and a total station?and a total station?

TheodoliteTheodolite Total station is a instrument havingTotal station is a instrument having

theodolite / total station / instrument / attachment / installation / readout

�� Manual Manual

installation installation

�� Manual Manual

readingreading of of

scalesscales

�� Automatic readoutAutomatic readout capabilitiescapabilities

�� Simple andSimple and quick installationquick installation on on

any groundany ground

�� Fast & easyFast & easy data transfer data transfer

toto tablet PC or notebook tablet PC or notebook

TheodolitesTheodolites can measure:can measure:

�� Horizontal anglesHorizontal angles

�� Vertical anglesVertical angles

�� DistancesDistances

�� ElevationsElevations

LevelsLevels can measure:can measure:

�� Horizontal anglesHorizontal angles

�� DistancesDistances

�� ElevationsElevations

MeasurementMeasurement accuracyaccuracy depends on manydepends on many factors.factors.

�� Instrument error (Model and type of instrument)Instrument error (Model and type of instrument)

�� Human error (Surveyors’ skill)Human error (Surveyors’ skill)

�� Natural error (Atmospheric conditions, wind speed, air Natural error (Atmospheric conditions, wind speed, air

temperature, atmospheric pressure, humidity, etc) temperature, atmospheric pressure, humidity, etc)

axis / measurement accuracy / error / skill / atmospheric condition / wind / humidity

What is the difference between a What is the difference between a theodolitetheodolite and a level?and a level?

What is the difference What is the difference

between a between a theodolitetheodolite

and a level?and a level?

leveling / control point / backsight reading / foresight reading

The bubble tubeThe bubble tube

Leveling with three foot screwsLeveling with three foot screws

leveling / line of sight / horizontal / bubble tube / vial screw / lever / clamp / tribrach

How to set How to set the line of sight (line of the line of sight (line of

vision ) to vision ) to be be exactly horizontalexactly horizontal??

high-tech / EDM / GPS / DGPS / global positioning system / differential / drone

�� EDM EDM (Electronic Distance Measurement system)(Electronic Distance Measurement system)

�� Total station Total station equipped with EDMequipped with EDM

�� GPSGPS (Global Positioning System)(Global Positioning System)

�� DGPS DGPS (Differential Global Positioning System) (Differential Global Positioning System)

�� DronesDrones for surveyingfor surveying

EDMEDM

Total StationTotal Station

Ordinary Ordinary

GPSGPS

DGPSDGPS

DroneDrone

EDM / transmitter / receiver / wave / retroprism /reflector

EDM EDM (Electronic Distance Measurement system)(Electronic Distance Measurement system)

Principle of EDMPrinciple of EDM

EDM / total station / equipped / capability

Total station Total station equipped with equipped with EDMEDM

(Optical and electronic measurement capabilities)(Optical and electronic measurement capabilities)

EDMEDM

Total StationTotal Station

GPS / satellite / space / maintain / transmission / signal / embedded/ position

GPSGPS (Global Positioning System)(Global Positioning System)

Regular Regular

GPSGPS

�� 24 Satellites in space, maintained 24 Satellites in space, maintained by US Militaryby US Military

�� Each satellite transmits a signal Each satellite transmits a signal with embedded timewith embedded time

�� GPS Unit receives signal and GPS Unit receives signal and records timerecords time

�� Position is calculated using Position is calculated using triangulation by determining how triangulation by determining how long each signal took to leave long each signal took to leave satellite and to then be received by satellite and to then be received by the GPS unitthe GPS unit

Regular GPS Regular GPS

receiverreceiver

CORS-TR

(Continuously Operating

Reference Stations)

PROJECT

CORS-

TR® PROJECT

ESTABLISHMENT OF

NATIONAL CORS

SYSTEM AND DETERMINATION

OF DATUM

TRANSFORMATION

PARAMETERS

establishment / national / datum / continuously / operating / reference / station

DGPS / principle / accuracy / correction / unknown / approximation / position

DGPSDGPS (Differential GPS)(Differential GPS)

Regular GPS Regular GPS

receiverreceiver

Standard GPS AccuracyStandard GPS Accuracy

�� Old was 100m accuracyOld was 100m accuracy

�� New is 15mNew is 15m

�� WAAS technology is less than WAAS technology is less than 3m3m

The basic principle of DGPS is to remove these errors The basic principle of DGPS is to remove these errors

by determining the difference between the measured by determining the difference between the measured

distance at an unknown pointdistance at an unknown point

whose position is to be fixed whose position is to be fixed

and an approximation of the and an approximation of the

true distance as calculated by true distance as calculated by

a receiver at a known position.a receiver at a known position.

DGPS UnitsDGPS Units

drone / airborne / image / model / generation / software

DronesDrones for surveying and 3D model generationfor surveying and 3D model generation

Everyday new software has been specifically created and Everyday new software has been specifically created and

released for generating 3D maps from drone images.released for generating 3D maps from drone images.

DroneDrone

topographic maps / marine works / bathymetric maps / seafloor map / sonar system

�� “Land surveying” for “Land surveying” for

“Topographic maps" “Topographic maps"

�� “Marine surveying” for “Marine surveying” for

“Bathymetric maps”“Bathymetric maps”

DroneDrone

Bathymetric Sonar SystemBathymetric Sonar System

Marine works: Marine works:

�� Costal protectionCostal protection

�� Ports and marinasPorts and marinas

�� Offshore structuresOffshore structures

density / salinity / conductivity / tide / current / wave / wave gage / buoy

�� Physical oceanographic parameters (Density, salinity, etc)Physical oceanographic parameters (Density, salinity, etc)

�� CTD (Conductivity, Temperature and Depth) CTD (Conductivity, Temperature and Depth)

�� Sea level variationsSea level variations

�� Current velocityCurrent velocity

�� Wave heightsWave heights

DroneDrone

Short and long term measurementsShort and long term measurements

Spatial data:Spatial data:

�� Data check and filtering Data check and filtering

�� CorrectionsCorrections

�� CalculationsCalculations

�� Plotting pointsPlotting points

�� Drawing contoursDrawing contours

spatial data / data filtering / correction / plotting / contour

Mapping TechniqueMapping Technique

�� Manual mappingManual mapping

�� Mapping softwareMapping software

Mapping TechniqueMapping Technique

�� Manual mappingManual mapping

�� Mapping softwareMapping software

Spatial data:Spatial data:

�� X,Y,ZX,Y,Z

�� Lat, Long, height (or Lat, Long, height (or

depth)depth) Mapping software such as Surfer, Mapping software such as Surfer, GrapherGrapher, MapInfo etc., MapInfo etc.

spatial data / latitude / longitude / contour map / terrain map / surface map

How do you measure approximately “How do you measure approximately “the height of a buildingthe height of a building” ”

withoutwithout any surveying tool?any surveying tool?