Technical English -I 5 th week SURVEYING AND MAPPING
What is surveying? It is the art of defining the positions of natural and man-made made features on the Earth s surface. Basic Tasks and Features in Surveying: Measurements Surveying tools and equipment Evaluation of survey data Mapping surveying / position / natural / man made / feature / equipment / mapping
Basic Engineering measurements: Distance distance interval length space Elevation Elevation (vertical position) is the height of a point relative to some reference point Angle Coordinates (X/Y or Lat/Long etc.) distance / elevation / angle / coordinates
Today 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 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
Traditional and contemporary (state-of- the-art electronic devices) surveying tools surveying tools / equipment / device / traditional / contemporary / state-of-the-art
steel tapes optical square chaining pins spring tension compass ranging rods & flag-pole theodolite level tripod Tripods are used for several surveying instruments, such astheodolites, total stations, levelsor transits. staff steel tape / chaining pins / spring tension / compass / optical square / ranging rods flag-pole / staff / theodolite / transit / total station / level / tripod
What is the difference between a theodolite and a transit? They are the same thing. Europeans tend to say "theodolite", which is the older term. Americans tend to say "transit." Both theodolitesand transits are instruments used by surveyors to measure horizontal and vertical angles, measure distances and determine elevations. Generally a theodolite is moreprecise in point of vernierincrements increments and optical systems. It hasmore incrementationson the circle. theodolite transit vernierincrements increments theodolite / transit / total station / instrument / precise / vernier / optics
What is the difference between a theodolite and a total station? The original theodolitewas a purely optical instrument, but nowadays most theodolites come with an electronic distance-measuring attachment called as total station. Total stations possess automatic angle and distance readout capabilities. Theodolite Manual installation Manual readingof scales Total station is a instrument having Automatic readout capabilities Simple and quick installationon any ground Fast & easydata transfer totablet tablet PC or notebook theodolite / total station / instrument / attachment / installation / readout
What is the difference between a theodoliteand a level? Theodolites can measure: Horizontal angles Vertical angles Distances Elevations Levels can measure: Horizontal angles Distances Elevations Measurement accuracy depends on many factors. Instrument error (Model and type of instrument) Human error (Surveyors skill) Natural error (Atmospheric conditions, wind speed, air temperature, atmospheric pressure, humidity, etc) axis / measurement accuracy / error / skill / atmospheric condition / wind / humidity
What is the difference between a theodolite and a level? leveling / control point / backsight reading / foresight reading
Leveling with three foot screws How to set the line of sight (line of vision ) to be exactly horizontal? The bubble tube leveling / line of sight / horizontal / bubble tube / vial screw / lever / clamp / tribrach
EDM (Electronic Distance Measurement system) Total station equipped with EDM GPS(Global Positioning System) DGPS (Differential Global Positioning System) Drones for surveying EDM DGPS Total Station Ordinary GPS Drone high-tech / EDM / GPS / DGPS / global positioning system / differential / drone
EDM (Electronic Distance Measurement system) Principle of EDM EDM / transmitter / receiver / wave / retroprism /reflector
EDM Total station equipped with EDM (Optical and electronic measurement capabilities) Total Station EDM / total station / equipped / capability
GPS(Global Positioning System) 24 Satellites in space, maintained by US Military Each satellite transmits a signal with embedded time GPS Unit receives signal and records time Position is calculated using triangulation by determining how long each signal took to leave satellite and to then be received by the GPS unit Regular GPS Regular GPS receiver GPS / satellite / space / maintain / transmission / signal / embedded/ position
CORS- TR PROJECT ESTABLISHMENT OF NATIONAL CORS SYSTEM AND DETERMINATION OF DATUM TRANSFORMATION PARAMETERS CORS-TR (Continuously Operating Reference Stations) PROJECT establishment / national / datum / continuously / operating / reference / station
DGPS(Differential GPS) Regular GPS receiver Standard GPS Accuracy Old was 100m accuracy New is 15m WAAS technology is less than 3m DGPS Units The basic principle of DGPS is to remove these errors by determining the difference between the measured distance at an unknown point whose position is to be fixed and an approximation of the true distance as calculated by a receiver at a known position. DGPS / principle / accuracy / correction / unknown / approximation / position
Drones for surveying and 3D model generation Everyday new software has been specifically created and released for generating 3D maps from drone images. Drone drone / airborne / image / model / generation / software
Marine works: Costal protection Ports and marinas Offshore structures Land surveying for Topographic maps" Marine surveying for Bathymetric maps Bathymetric Sonar System Drone topographic maps / marine works / bathymetric maps / seafloor map / sonar system
Physical oceanographic parameters (Density, salinity, etc) CTD (Conductivity, Temperature and Depth) Sea level variations Current velocity Wave heights Drone Short and long term measurements density / salinity / conductivity / tide / current / wave / wave gage / buoy
Spatial data: Data check and filtering Corrections Calculations Plotting points Drawing contours Mapping Technique Manual mapping Mapping software spatial data / data filtering / correction / plotting / contour
Spatial data: X,Y,Z Lat, Long, height (or depth) Mapping software such as Surfer, Grapher, MapInfo etc. Mapping Technique Manual mapping Mapping software spatial data / latitude / longitude / contour map / terrain map / surface map
How do you measure approximately the height of a building without any surveying tool?