Modern survey Instruments (2).pdf

This is for geomatics student

1. ModernSurveyingInstruments
Er.Nabaraj subedi
Instructor
LandManagementTrainingCenter

2. SurveyingInstruments
Instrumentsusedforthemeansofsurveying
Insurveying,usuallytheinstrumentsareusedtomeasuredistance,angle
ordirectlycoordinatesofanypointon earthsurface.
The rapidadvancementin scienceandtechnologyhasmodernizedthe
traditionally used survey instrument and brought some revolution in
developingmodernsurveyinstruments.
The developmentofmodernsurveyinstrumentshasmadesurveyingand
mappingtasksimpler

3. ConventionalSurveyInstruments
Conventionallysurveyinstrumentsareusedforestablishingthenetworksof
horizontaland verticalcontrolpointsandtheir coordinateswith theaccurate
observationofangle anddistance.
Thecomplexcomputationofarea, perimeter,volumeetc.wasdoneusing
analogsystemormanually
Somewidelyusedtraditionalsurveyinstrumentsare
Chain/Tape
Theodolite
Compass
PlaneTable
Allidade
Clinometer

4. ModernSurveyInstrument
EDM(ElectromagneticDistanceMeasurement)
TotalStation
GNSS (GlobalNavigationSatelliteSystem)
UAV(UnmannedAerialVehicle)
INS(InertialNavigationSystem)

5. EDM(ElectromagneticDistance
Measurement)
Electro/ opticmedium,calculatesthedistanceby measuringradiated
electromagnetic wave(suchasinfraredlightorlaserlightormicrowave)from
theEDM’smainunit,whichreturnsby being reflectedthroughthe reflector
Method
◦Settingup(Centering/Levelling/Focusing)
◦Sightingandobservationoftarget
◦Horizontal/slopedistance
Use
◦Distance measurementintraverse/triangulation
◦Alllineardistancemeasurement
Instruments used
◦EDMset
◦Prism

6. OperationsinNumericalSurvey:
EDM
Checkingandadjustmentofequipment
◦Temporaryadjustment(Setting,Centering,Levelling)
◦PermanentAdjustment
Reconnaissanceofarea specifiedforsurvey
◦Inspection of areatobe surveyed,collect preliminaryinformation,preparerough
sketchObservation
◦Observationoflineardistance
Fieldbook
◦Calculationofhorizontal distance
◦Errorcalculation andadjustment
Plotting anddrawing

7. Propertiesofelectromagnetic
waves

Electromagnetic wave forms periodic sinusoidal waves. Since these waves are
sinusoidalin nature;theycompletecyclesinmovingfromidenticalpoints fromAtoE
orB

Thenumberoftimesthewavecompletesacompletecycleinonesecondisknownas
thefrequencyofthewave.Itisdenotedbyf.Itismeasuredinhertz(Hz).1hertzofa
wavereferstoonecompletecycleinonesecond.

Thelengthtravelledbythewavein one cycleisknownas thewavelengthof a wave.It
isdenoted byλand measuredinmetres (m).

Thetimetakenby wavetotravel onecycleisknownastimeperiodor simply period.
It isdenotedbyTandmeasuredinseconds(s)

Distance travelled by wave in time t is termed as velocity of the wave. It is denoted by
v and measured in m/s. The velocity v depends upon medium through which the wave is
travelling. The velocity of wave refers to the speed of light. It is denoted by c with
assumedvalue to be 3 x 108 m/s.

8. Propertiesofelectromagnetic
waves

The frequency (f), wavelength (λ) and period (T) varies with the production of waves
from different sources. The relation between these terms can be expressed in terms of
equation:
f=c/λ=1/T

Phaseisanotherpropertyofelectromagneticwave.Phaseisthefractionof thewave
cycle which has elapsed relative to the origin. Also known as angle of a sinusoidal
function at its origin or departure. This is denoted by φ. It is measured as nth of
wavelength for e.g. 1/100 th of (λ). EM waves can be generated in different frequency
bands:radio,microwave,infrared,visible,ultraviolet,x-rays,gammarays.

9. PrincipleofEDM
2D=nλ+ φ
WhereDisthetotaldistancetravelledbythewaven= wholenumberofwavelength
travelledbythewave;λ=wavelengthφ=fractionof wavelengthtravelledby wavei.e
phase differenceφ=(φ2 –φ1)Where,φ1=phaseofwaveasitistransmittedatsource
instrumentφ2=phaseofwaveasitisreceivedatthereceiver
Q.CalculatethedistancemeasuredbyanEDMwithfollowingwavepatternofwavelength
40m.(60m)

10. TypesofEDMInstruments
Onthebasisoftypeof carrierwaveemployedEDMInstruments canbe dividedinto
followingcategories:
a.Microwaveinstruments
E.g.Tellurometer (range:up to100km withaccuracyof +/-15mm to5mm/km)
b.Visiblelightsinstruments
E.gGeodimeter(range2-3km with the accuracyof+/-0.2mm/km)
c.Infraredinstruments
E.gDistomats(range2-5km withtheaccuracyof+/-10mm/km)
AnotherexampleofEDMisTotalstation.Totalstationisaninstrumentthatserves
both indeterminationofcoordinatesandelectronicdistancemeterorEDM.

11. ErrorinEDM
Zeroor IndexErroris causedbythreefactors:
•electricaldelays,geometricdetours,andeccentricitiesintheEDM
•differencesbetween theelectroniccentreandthemechanicalcentreof theEDM
•differencesbetween theopticalandmechanicalcentersofthe reflector.
Scaleerrordescribeserrorsthatarelinearlyproportionaltothelengthoflinemeasured.
•internalfrequencyerrors,includingthosecausedbyexternaltemperatureand
instrument"warm-up"effects
•un-modeledvariationsinatmosphericconditionswhichaffectthevelocityof
propagationnon-homogeneousemission/receptionpatternsfromthe emittingand
receivingdiodes(phaseinhomogenities).
CyclicError(ShortPeriodicError)isafunctionoftheactualphasedifferencemeasurement
bytheEDM.Phasemeasurementerroriscausedbyunwantedfeedthroughthetransmitted
signalontothereceivedsignal.

12. TotalStation
Measurementofangleanddistancebetweentwopointswiththeapplicationofelectromagneticradiation
andcomputethecoordinatesofstations
MeasurementofcoordinatesofpointswiththeapplicationofEMwavesanduseofatleasttwoknown
coordinates
Method
◦Settingup(Centering/Levelling/Focusing)
◦Sighting andobservationoftarget
◦Angle anddistancemeasurement(coordinatecomputation)
Use
◦Control points establishment
◦Detailsurvey:Topographicalsurvey/EngineeringSurvey
◦CadastralSurvey
◦TrigonometricLevelling
Instrumentsused
◦Totalstationset
◦Prism

13. OperationsinTotal Station
•Checkingandadjustmentofequipment
◦Temporaryadjustment(Setting,Centering,Levelling)
◦PermanentAdjustment•Reconnaissanceofarea specified forsurvey
◦Inspection of areatobe surveyed,collect preliminaryinformation,preparerough
sketch
◦Selectionofstations
•Observation
◦Observationof angleanddistanceorcoordinates
Fieldbook
◦Digitalcoordinates
◦Errorcalculation andadjustment
•Plottingand drawing

14. BasicCalculations
TotalStationsmeasure threemainparameters:
•
HorizontalAngle
•
VerticalAngle
•
SlopeDistance
HorizontalDistance
Itis firstnecessarytoconvertthe slopedistancetoahorizontaldistance.
Thehorizontaldistanceis
Hd=Sdcos(90*–Za)=SdsinZa
whereSdis the slopedistanceandZais the zenithangle.Thehorizontal
distancewillbe use in the coordinatecalculations.

15. ImportantFeatures
1.
Keyboard-control-allthefunctionsarecontrolledbyoperatingkeyboard.
2.
Digitalpanel-thepaneldisplaysthevaluesofdistance,angle,heightand
thecoordinatesoftheobservedpoint,wherethereflector(target)is kept.
3.
Remoteheightobject-theheightsof some inaccessibleobjects such as
towerscanbereaddirectly.Themicroprocessorprovidedintheinstrument
appliesthecorrection forearth’scurvatureandmeanrefraction,
automatically.
4.
Traversingprogram-thecoordinatesofthereflectorandtheangleor
bearingonthereflectorcanbestoredandcanberecalledfornextsetupof
instrument.
5.
Settingoutfordistancedirectionandheight-wheneveraparticular
directionandhorizontaldistanceis tobeenteredforthepurposeof
locatingthepointonthegroundusingatarget,thentheinstrument
displays theanglethroughwhichthetheodolitehastobeturnedandthe
distanceby whichthe reflectorshould move.

18. Sourceoferrorsinangular
measurement
Horizontalcollimation(orlineof sight)error
VerticalCollimation (ofverticalindex)Error
Tilting axis error
Compensatorindexerror
AtmosphericEffects

19. GNSS
◦GlobalNavigationSatelliteSystem
◦Measurement of coordinate of a point from the application of satellites
(Trilateration):Determinationof coordinateswiththehelpof known ranges
Method
◦Settingup(Centering/Levelling)
◦CoordinateobservationUse
◦Controlpointsestablishment
◦Detailsurvey:Topographicalsurvey/EngineeringSurvey
Instrumentsused
◦GPSinstrument(baseandrover)

20. OperationsofGNSS
•Checkingandadjustmentofequipment
◦Temporaryadjustment(Setting,Centering,Levelling)
◦PermanentAdjustment•Reconnaissanceofarea specified forsurvey
◦Inspection of areatobe surveyed,collect preliminaryinformation,preparerough
sketch
◦Selectionofstations
•Observation
◦Observationofcoordinates
Fieldbook
◦Coordinates,GDOP,PDOP,numberofsatellites
◦Errorcalculation andadjustment
◦CoordinateTransformation
•Plottingand drawing

22. GNSSprinciple

23. Observed data of GNSS
stations are processed
with referenceto
certainepochand
obtainedcoordinates
areusedtomakemaps
or mapsproducts.

24. ErrorsinGNSS
1.Satellite Geometry
2.Satellite Orbits
3.Multipath Effect
4.AtmosphericEffects
5.ClockInaccuracies

25. MethodsofcorrectingGPSerrors
1.Real Time Correction
2.Post-ProcessingCorrection
3.SatelliteDifferentialServices
NUMERICALSURVEYING-SUSHMITATIMILSINA

26. AnUnmannedAerialVehicle(UAV)isanaircraftwithouta
humanpilot.
It’sflightiseithercontrolledautonomouslybycomputers
orundertheremotecontrolofapilotontheground.
UAV(UnmannedAerialVehicle)

27. DEFINITION&
DIFFERENCEWITHMISSILES
.
UAVisdefinedasa
"powered,aerialvehiclethatdoesnotcarryahumanoperator,usesaerodynamic
forcestoprovidevehiclelift,canflyautonomouslyorbepilotedremotely,canbe
expendableorrecoverable".
CruiseMissilesarenotconsideredUAVsbecause,
likemanyotherguidedmissiles,thevehicleitselfisan
weaponthatisnotreused,eventhoughitisalsounmannedandinsome
casesremotelyguided.

28. TYPEALTITUDERANGE
HANDHELD 600m 2-5km
TACTICAL 5500m 100km
MALE
(mediumaltitude
longendurance)
7000m 200km
HALE
(highaltitudelong
endurance)
9100m 250km
HYPERSONIC 15200m 300km
TypesofUAVintermsofaltitude

30. UAV:Functionalstructure

31. PAYLOADS
Itisthecarryingcapacityofanaircraftorlaunchvehicle,usually
measuredintermsofweight.
Drivenbytheneedsoftheoperationaltask.Thesecanrange from:
(a)simplesub-systemsconsistingofvideocamerawithafixedlens
havingamassaslittleas200g,through
(b)avideosystemwithagreaterrangecapability,employing a
longerfocallengthlens withzoomfacility,gyro-stabilisedandwithpan
andtiltfunctionwithamassofprobably3–4kg,to
(c)ahigh-powerradarhavingamass,withitspowersupplies,of
possiblyupto1000kg.
SomemoresophisticatedUAVcarrya combinationofdifferenttypesof
sensors,withinapayloadmoduleorwithinaseriesofmodules.

32. TheAirVehicle
Dependingonneedsoftheoperationalmissionairvehicleisdesigned
primarilytask istocarrythemissionpayloadtoitspointof
application,
operationalrange,airspeedandendurance.
Theenduranceandrangerequirementwilldeterminethe
fuelloadtobecarried.

33. NavigationSystems
Itisnecessaryfortheoperatorstoknow,ondemand,wheretheaircraftis
atanymomentintime.
Forfullyautonomousoperation,i.e.withoutanycommunicationbetween
the CS and the air vehicle, sufficient navigation equipment must be
carried in the aircraft. This was achieved by radio tracking or by the
recognitionofgeographicalfeatures.While GPS services a seamless
navigation with cheap receiver, it may not receive the satellite signal by
the obstacles or the signal jamming. It is GPS/INS(inertial navigation
system) sensor fusion that might overcome these constraints. The ground
test showed that GPS/INS sensor fusion system could provide well the
altitude information as well as the trajectory according to a vehicle
movement.

34. Communications
The principal, and probably the most demanding, requirement for the
communicationssystemistoprovidethedatalinks(upanddown)between
theCSandtheaircraft.
(a)Uplink(i.e.fromtheCStotheaircraft)
i)
Transmitflightpathtaskingwhichisthenstoredintheaircraftautomatic
flightcontrolsystem
ii)
real-timeflightcontrolcommandssuchas updatedpositionalinformation
totheaircraftINSwhererelevant.
(b)Downlink(i.e.fromtheaircrafttotheCS)
i)Transmitaircraftpositionaldata
ii)payloadimagery
iii)aircrafthousekeepingdata,e.g.fuel state, enginetemperature,etc.to
theCS.

35. APPLICATIONS
A.BeyondthemilitaryapplicationsofUAVswithwhich "drones"becamemost
associated,numerouscivilaviationuseshavebeendeveloped,including
B.aerialsurveyingofcrops(landsurveying)
C.acrobaticaerialfootageinfilmmaking,
D.searchandrescueoperations,
E.inspectingpowerlinesandpipelines,
F.countingwildlife,
otherwiseinaccessibleG.deliveringmedicalsuppliestoremoteor
regions,
H.surveillance&borderpatrolmissions,
I.forestfiredetection,
J.detectionofillegalhunting,
K.fireandlargeaccidentinvestigation,
L.landslidemeasurement,
M.illegallandfilldetection,
N.andcrowdmonitoring.

36. DISADVANTAGE

Civiliancasualties

Can behackedorgivenviruses

Toosmallfortransportationoflargematerials

Lowresistancetoweather

Cannotrefuelinflight

Ifcontactislostwiththegroundstation,the
vehiclemaybelost.

37. INS(InertialNavigationSystem)
An inertial navigation system (INS) is a navigation device that uses a
computer, motion sensors (accelerometers) and rotation sensors
(gyroscopes)tocontinuouslycalculatetheposition,the orientation,and
the velocity (direction and speed of movement) of a moving object
withouttheneedforexternalreferences.(Wikipedia,2020)
INSsareusedonmobilerobotsandonvehiclessuchasships,aircraft,
submarines,guidedmissiles, andspacecraft.

38. Application
Odometer
VisionGuidedNavigation
SensorFusion(GNSS+INS)

39. THANKYOU