Metrology, Instruments, Sensors, Beaconing,...

Metrology, Instruments, Sensors, Beaconing, SignalisationMetrology, Instruments, Sensors, Beaconing, Signalisation

ETH ZurichEngineering Geodesy - Prof. Dr. H. Ingensand

ContentContent

OverviewGeneral Specification (Quality) of Sensors/Instruments/MethodsSensors/Instruments/Methods

1D Length –Height – Alignment- Plumbing-Direction-Rotation

2D Coordinates/Position

3D Coordinates/Position

Beaconing/Centring/Signalisation


The Variety of Sensors,Instruments and Methods in EG


Monitoring Sensors, Instruments: OverviewMonitoring Sensors, Instruments: Overview

Pressure sensorsHydrostatic systemsDisplacement transducers (extensometers crack and jointmeters etc )

GEO

PHY

Geotec

Displacement transducers (extensometers, crack- and jointmeters, etc.)Strain gauges (tension gauges)Tiltmeters, including vibrating wireLoad cells (force measurement)

YSICS

hnics

Load cells (force measurement)Fixed removable micrometers (FIM)Optical fiberOptical positioning sensors

Optical positioning sensors

Motorised total stations; Terr. ScannerGPS

GEO

D

Digital levels, including those with motorisationRemote Sensing methods

DESY

Meteorological sensorsTemperature sensorspH and conductivity metersG

CH

EMIST


Gas sensors

TRY

Methods:Accuracy versus RangeMethods:Accuracy versus Range

ccur

acy

Ac

Size of the Object


Geodetic Measurement Scenario for Slope MovementsGeodetic Measurement Scenario for Slope Movements

GPS

Referenzpunkt

GPS

Referenzpunkt

T MOTDIGNIV MOT

Reflektor

Standpunkt

T_MOTDIGNIV_MOT Referenzpunkt


Slope MovementsSlope Movements


General Specification (Quality) of Sensors/Instruments/MethodsGeneral Specification (Quality) of Sensors/Instruments/Methods

Accuracy / Precision/ ResolutionLinearityLinearityCalibration Stability (long term stability)Stability (long term stability)SynchronisationInterfaces/ Remote controlInterfaces/ Remote controlPower level; Power ConsumptionP t t d i t t i flProtected against meteo-influencesElectromagnetic shieldingA il bilitAvailabilityCustomer SupportC t


Costs

Sensors/InstrumentsSensors/Instruments1D Length 1D Length ––Height Height -- AlignmentAlignment

2D Coordinates/Position2D Coordinates/Position2D Coordinates/Position2D Coordinates/Position

3D Coordinates/Position3D Coordinates/Position3D Coordinates/Position3D Coordinates/Position

“Imaging” Systems“Imaging” Systems


One Dimension: Distance

Single/Multi Distance MeasurementsSingle/Multi Distance Measurements

--Extensometers Bars/Wires/FiberExtensometers Bars/Wires/Fiber--Optical Sensors (relative Distance)Optical Sensors (relative Distance)--EDM (relative and absolute distances)EDM (relative and absolute distances)--EDM (relative and absolute distances)EDM (relative and absolute distances)


Instrumentation for Rockfall MeasurementsInstrumentation for Rockfall Measurements

Extensometer

Inclinometer


Extensometer (WireExtensometer (Wire-- & Bar& Bar--Extensometer)Extensometer)

Bar Extensometer

One or multiple bars, shielded by plastic coating, are fixated at one end with an anchor plate in the rock/concrete. The relative distance variation is measured by micrometers or inductive length


y gtransducers

Borehole Extensometer “Nalps” Borehole Extensometer “Nalps”


Teletensometer (Huggenberger)Teletensometer (Huggenberger)


Telejointmeter (Huggenberger)Telejointmeter (Huggenberger)


DistometerDistometer System (System (ISETHISETH), Developed at ETH), Developed at ETH


Wire Extensometer Distometer ISETHWire Extensometer Distometer ISETHManufacturer: SOLEXPERTSManufacturer: SOLEXPERTS Length: Invar-wires from 1 to 50 mRange: 100 mmRange: 100 mmAccuracy: 0,02mm@ 20m

Function principle: The wire is constantly tensioned by a spring. The tension is adjusted by the screw S and the correct value can b h k d b th di l MK Th di l M i di t th l thbe checked by the dial MK. The dial M indicates the length variation. The length of the wires can be checked against the interferometer of IGP


interferometer of IGP

Wire Extensometer (ISETH)Wire Extensometer (ISETH)


Crack Meter (Rissmikrometer)Crack Meter (Rissmikrometer)


Extensometry (Deformeter/Huggenberger)Extensometry (Deformeter/Huggenberger)

Manufacturer: Huggenberger AG Zurich

Length: 250/500 mmLength: 250/500 mm

Range: 5 mm

Accuracy: 0.002 mm


Fiber Optical SensorsFiber Optical Sensors


Interferometry: SOFO V System Interferometry: SOFO V System

PCSOFODB

SOFO reading Unit

OpticalSwitch Standard Sensors

C l

Modem

Membrane Sensors

LED

A/D

Coupler

LEDPhoto-

Mobile Mirror

Micro Controller

Modem

RS232

Other SOFO Sensors (Force, T,…)Data-logger

LEDLEDPhoto-Diode

RS232

SOFObus

Bridge Data Acquisiton Units

ETH ZurichEngineering Geodesy - Prof. Dr. H. IngensandClick or press spacebar to advance in the animation

SOFO DynamicSOFO Dynamic

Functional Principle:rs

Structure under test CouplerM

irro

SOFO DynamicDemodulator

Phase Modulator

Photo-Diode

Laser1550nmDigital Output

DSPAnalog Output


Standard Sensor InstallationStandard Sensor Installation

BoreholeInjection

Surface Installation

Concrete Embedding


Embedding

Fiber Bragg Grating SensorsFiber Bragg Grating Sensors

Ca. 1cmCa. 1cm

The reflected wavelengthThe reflected wavelengthThe reflected wavelengthThe reflected wavelengthdepends on the strain anddepends on the strain andtemperature of the fibertemperature of the fibertemperature of the fibertemperature of the fiber


Distributed SensingDistributed Sensing

Reading Unit T1g

Distributed Sensor0m

1

T2. [°C

]

T1

1m 100m

P iti [ ]

Tem

p

F

ε

με]

1000m Position [m]

FF

Stra

in [μ

20km εT2

Position [m]

SETH ZurichEngineering Geodesy - Prof. Dr. H. Ingensand

Electro optical distance meter (EDM)Electro optical distance meter (EDM)


DICLAS: Continuous Distance Measurement by laserDICLAS: Continuous Distance Measurement by laser


Dimetix PolydistDimetix Polydist


2D Alignment tools2D Alignment toolsgg-- wireswires-- optical alignmentoptical alignment

l li tl li t-- laser alignmentlaser alignment


Alignment Principle (Dam Monitoring)Alignment Principle (Dam Monitoring)

LaserAlignment

Instrument

Tubular Level

Targets

Pillar

Principle of optical alignment:

Pillar

Principle of optical alignment:Between two permanently installed points (alignment instrument and target mark (Mire)) a vertical plane is set. Measured are the shortest horizontal distances between the alignment points (marked with alignment target signs) and the vertical


g p ( g g g )layer.

Optical Alignment (Freiberger Präzisionsmechanik)Optical Alignment (Freiberger Präzisionsmechanik)


2 D Plumbing2 D Plumbing

-- optical plumbingoptical plumbing-- mechanical plumbing (wires)mechanical plumbing (wires)-- mechanical plumbing (wires)mechanical plumbing (wires)


Optical PlumbsOptical Plumbsä Nadir/Zenith Plumb LeicaZenith Freiberger Präzisionsmechanik

Messgenauigkeitmittlerer Lotfehler auf 100m ±1 mm100m

Fernrohr

Bildlage aufrecht, seitenrichtig

Vergrößerung 32 xkürzeste Zielweite 2,2 m

freier Objektivdurchmesser 40 mmObjektivdurchmesser

KompensatorArbeitsbereich ± 10´

mittlerermittlerer Einspielfehler ± 0,15"

TemperaturArbeitsbereich -25°C...+45°CInstrumentAbmessungen 140 x 295 mmGewicht 3,5 kg


MechanicalMechanical PlumbingPlumbing

Measuring plumb lines on top Guide Roller


Measuring plumb lines on top Guide Roller

Mechanical Plumbing: bottomMechanical Plumbing: bottom

Observation using T 2002


Computation of the damped OscillationsComputation of the damped Oscillations

U [m]

U1

U2

U3

U4

U5

t [s]

u ui i+⎛ ⎞1 2 [ ]mim u u uii i

i= ⋅+

+⎛⎝⎜

⎞⎠⎟

++

12 2

21

[ ]xmn

i=


n

Principle of Multi Weight PlumbingPrinciple of Multi Weight Plumbing

on

aa

= PP

1 2

ed P

ositi

o

a P2 1

Com

pute

a =

P1 2− −aa

PP

2

2

1

1

aa

Pa

P2 1=a

und a =a1 2− −


aP P

PP P

P12 1

21 2

1 = und a =2−⋅

−⋅

Influences in Mechanical PlumbingInfluences in Mechanical Plumbing

Torsional OscillationsTorsional OscillationsOscillations induced by spiral whirls in the shaft Water dribsWater dribsPlumb line deviations by eccentric plumb wirePlumb line deviations by in-homogenous gravity distributionPlumb line deviations by in-homogenous gravity distribution


Direction determination or direction transferDirection determination or direction transferDirection determination or direction transferDirection determination or direction transfer

TheodolitesTheodolites-- TheodolitesTheodolites

-- GyrotheodolitesGyrotheodolitesyy

-- Inertial Navigation Systems Inertial Navigation Systems


Gyroscope MeasurementsGyroscope Measurements

Absolute azimuth measurementDirection transferDirection transfer

How it works:G h d f f dGyro has two degrees of freedom

• No rotation around horizontal axis(realized by gravitation, fixed in horizontal plane)

• Rotation around HH (gyro axis) and VV (vertical axis)

Gyrotheodolit „Gyromat 3000“.Source: http://www.gyromat.de

• Rotation around HH (gyro axis) and VV (vertical axis)Due to inertia the rotating gyro keepsits positionEarth rotation causes deviation of the plumbline by centrifugal forces of suspensionGyro starts to rotate around plumb lineGyro starts to rotate around plumb line(precision)Gyro axis orientates to the geographical

th di ti


north directionPrinciple of a gyro with two degrees of freedom and deflecting force diagram.Source: Instrumentenkunde Deumlich/Staiger


Earth rotation and local plumb line influence gyro measurementsaccording to astronomical azimuthaccording to astronomical azimuth

Required corrections and reductionsChandler Wobble (instantaneous rotation axis CIO pole)Deflection of vertical (astronomical azimuth ellipsoidical azimuth)

ξ: north-south component, η: east-west component

Chart convergence (ellipsoidical azimuth -> plane azimuth)

Reduction of direction (great circle -> straight line)



Keep in mind:The first two corrections/reductions baseThe first two corrections/reductions base on physical conditions, the second two are purely mathematicalFor relative azimuth measurements (directiontransfer) the last three corrections/reductionsare sufficient for most applicationsare sufficient for most applicationsCorrection of influence of vertical deflection

• in Switzerland (Latitude ca. 45°) the north-southcomponent has the factor 1 (tan 45° = 1)

• Differences in vertical deflections aredecisive (reference track -> tunnel track)Thi i i t t t l l t k• This is in contrast to polygonal networks,where the vertical deflection has only an impactfor steep sightings (tunnel sightings are usually horizontal)

„Gyromat 2000“ measuring in the Gotthard basetunnel near Faido.Source: Stephan Schütz


y )

Inertial Measurement SystemInertial Measurement System

3 orthogonal acceleration indicators

3 orthogonal gyroscopes3 orthogonal gyroscopese.g. ring laser gyros, integrated gyros

Coaxial arrangement

P i itProcessing unit


Measurement Setup in the ConveyorMeasurement Setup in the Conveyor


Measurement Setting Measurement Setting (Dissertation (Dissertation NeuhierlNeuhierl, 2005), 2005)

Adapting mirrorAdapting mirrortop

bottom

mirrorψ

shaftconveyormounting-

lGAP

IMU

plateGAP

βo

αo

topαu

βlong-distance target location

top βu

bottom


bottom

Results pit Results pit SedrunSedrun (Dissertation (Dissertation NeuhierlNeuhierl, 2005), 2005)

Difference between tunnel network and IMU: Δ = 2.2 mgonA priori analyses: ca. 1.5 mgonp y g

Difference is not significant, no further corrections required

Advantage using two independent methods: increase in reliability

Honeywell QA2000 accelerometers. ($2,920 to $17,045 US)One-year Composite Repeatability [μg] <160


Honeywell GG1320 ring laser gyro.Source: www.honeywell.com

Source: www.honeywell.com IMAR IMU with QA2000 and GG1320.Source: www.imar-navigation.de

Inclination SensorsInclination Sensors


Liquid Surface with optical position sensor (PSD)Liquid Surface with optical position sensor (PSD)


Borehole Inclination SensorBorehole Inclination SensorUse: landslide monitoringPrinciple: pendulum causes amplitude detected by position sensor, reset force of servo motor is measured in volts.

ETH ZurichEngineering Geodesy - Prof. Dr. H. IngensandFixed bottom point

Height DeterminationHeight Determination

-- Levelling Levelling -- motorised digital levelling for permanent monitoringmotorised digital levelling for permanent monitoring-- hydrostatic systemshydrostatic systems-- hydrostatic systemshydrostatic systems


Permanent Monitoring with Motorised Digital LevelsPermanent Monitoring with Motorised Digital Levels

SolexpertsSolexperts


Hydrostatic systemsHydrostatic systems


Basic Setup of a Hydrostatic Levelling SystemBasic Setup of a Hydrostatic Levelling Systemp = ρ g h

Glass cylinder

Height of water column

Glass cylinderwith scale

g

Valve

Metal standMetal stand


FreibergerFreiberger SchlauchwaageSchlauchwaage

• Range: 100 mm

Parameters:circular level

g

• Tube length: 30-50 m

• Accuracy: 0.01 mm mm-scale

centeringplug gauge

Air pressure compensation tube(in closed rooms)

System specific errors:

Screw for levelling

Probe tipy p

• Capillary forces

• Vibrations of fluid-column g

Stop Valve

• Fluid-viscosity

Stop Valve


“Aachener Schlauchwaage”“Aachener Schlauchwaage”

Use: geomonitoring, detection of settlements

Principle: permanent magnet and electrical pulses on aand electrical pulses on a wire cause changes in the length of the wire, which is measured by ultrasonic TOA

Range: 10 mmAccuracy: 0.02 mm


HLSHLS –– Hydrostatic Levelling SystemHydrostatic Levelling SystemPrecise levelling – low tiltFluid velocity – slow movements

Technical Data:Range: 45 mmResolution: <2 microns (0.002 mm)( )Accuracy: <10 microns (0.010 mm)

Principle: fill level is determined capacitively. Fluid

z

ysurface and electrode act as capacitor plates.

x yCross Section of HLS level sensor

Source: IWAA2004 CERN


3D Measurement Systems3D Measurement Systems

GPS/GLONASSGPS/GLONASSG S/G O SSG S/G O SS

V M SV M SVector Measurement SystemsVector Measurement Systems-- Total Stations/Tacheometers/LasertrackerTotal Stations/Tacheometers/LasertrackerTotal Stations/Tacheometers/LasertrackerTotal Stations/Tacheometers/Lasertracker


Total Stations (Total Stations (egeg. Trimble VX Spatial Station). Trimble VX Spatial Station)Example: Trimble VX Spatial Station

Similar to Trimble S8 (except Fine Lock)Accuracy: distance 3 mm + 2 ppm angle 0 3 mgon (1“)Accuracy: distance 3 mm + 2 ppm, angle 0.3 mgon (1 )Robotic operation (one man operable)Scanning functionality

range < 150 m speed typical 5 Pts/s minimum point spacing 10 mm• range < 150 m, speed typical 5 Pts/s, minimum point spacing 10 mm,3D point accuracy 10 mm @ ≤150 m

Integrated camera• 2048 x 1536 pixels video stream 5fps2048 x 1536 pixels, video stream 5fps

Trimble VX Spatial Station.S htt // t i blSource: http://www.trimble.com


Ortho image station concourse Zurich Mainstation, captured with Trimble VX. Source: terra vermessungen ag

Stochastic and systematic Effects

Instruments Line of sight Target

• Deviations of the instrument • Meteo (Pressure, Temperature, • Alignment of the Prism (internal) Humidity)

• Temperature influences • Refraction (-> HZ, V) • Pollution of Prism

• Torsion of the instrument • Optical Elements in the line of • Stability of the pillar Torsion of the instrument Optical Elements in the line of sight

Stability of the pillar

• Pollution of the lenses • Expansions


from temperature

Metrology OverviewMetrology Overview


Overview: Geodetic Metrology MethodsOverview: Geodetic Metrology Methods

Metrology methods

Geometric information

Resolution Advantages Disadvantages

Levelling Changes of the local z-coordinate;

1/100 mm Simple; perpendicular relation independent of object

No automation with optical levels, refraction influence

Hydrostaticheight measurement

Relative changes of the local z-coordinate

1/100 mm No refraction influence, permanent

Time intensive installation, problem of coupling influencemeasurement of coupling, influence of temperature

Distance measuring5-2000 m

Distance, change of distance

1/10 mm Permanent; reflectorless for

Just one distance; refraction influence5-2000 m distance reflectorless for

suitable surfaces and angles

refraction influence

Distance measuring Change of distance < 1/100 mm Permanent; no Change of directionDistance measuring0-5 mInvar bars,- wiresFiberoptical

Change of distance < 1/100 mm Permanent; no refraction influence

Change of direction only, problem of coupling, just one distance


Fiberoptical sensors

Overview: Geodetic Metrology MethodsOverview: Geodetic Metrology Methods

Metrology methods



Tilt meter Rotation around x or y < 1“ (0 3 Permanent perpendicular Problem of couplingTilt meterInclinometerBorehole-Inclinometer

Rotation around x- or y-axis

< 1“ (0.3 mgon)

Permanent, perpendicular relation

Problem of coupling

Vector measuring Direction- and distance <1 mgon Independent of superior Refraction; needsVector measuringTotal stationElectronic tacheometer

Direction- and distance changes → local 3D-coordinates

<1 mgon Independent of superior systems; „Real-time“-analysis, simple target points (reflectors, reflex foils)

Refraction; needs reference points

foils)

Laser ScanningMicrowave-Interferometry

Pointcloud- Surface models

1-3 cm

1 mm

Reflectorless MeasurementsHigh sampling rate

Depends on the Surface parameteres,postprocessingy

Photogrammetry1 mm g p g p p g

3D-coordiantes designation

Global 3D-coordinates in WGS84-system

1 mm x,y3 mm z

„Real-time“ – analysis possible with fix-

Free sight to satellites, transformation of

GPS (differential phase measuring)

installation parameters necessary for linking with other data


Overview: Geodetic Metrology Methods Overview: Geodetic Metrology Methods

Metrology methods



Gyroscop Direction related to the 1 3 mgon Related to a physical TemperatureGyroscopAzimuth finding systems

Direction related to the Rotation axis of the Earth

1,3 mgon Related to a physical Direction

TemperatureDrifts

Inertial Navigation Position Rotations dm Independent from Temperature DriftsInertial Navigation Systems

Position, Rotations dm Independent from reference points

Temperature Drifts complicated calibration

Plumbing- optical plumbing- mechanical plumbing

Transfer of Local vertical 1:500 Related to a physical value Refraction (optical)

Alignment-Optical alignement- Mechanical alignment

Deviation of a line 0,01 mm Refraction (optical)


Overview: Geodetic Metrology Methods for Slope InstabilitiesOverview: Geodetic Metrology Methods for Slope Instabilities

Metrology methods



Gyroscop Direction related to the 1 3 mgon Related to a physical TemperatureGyroscopAzimuth finding systems

Direction related to the Rotation axis of the Earth

1,3 mgon Related to a physical Direction

TemperatureDrifts

Inertial Navigation Position Rotations dm Independent from Temperature DriftsInertial Navigation Systems

Position, Rotations dm Independent from reference points

Temperature Drifts complicated calibration

Radar Interferometry Interferometric pattern mm High resolution Surface propertiesDoes not work on vegetated surfaces


Engineering Engineering GeodesyGeodesy……

Remember:Remember:Engineering geodesy consists of more than just use total stations and/or GNSSUse your creativity to solve a specific problemThink about all the geomatics disciplinesThink about all the geomatics disciplines

PhotogrammetryRemote SensingRemote SensingGeodesyGISGIS...


Beaconing, Centering Systems, Reference PointsBeaconing, Centering Systems, Reference Points


Centring Centring SystemsSystems

Different systems (more or less) available, each has ist own e e t syste s ( o e o ess) a a ab e, eac as st oadvantages and drawbacks

Wild/LeicaKernZeissZeiss

Zeiss centering system (Zeiss-Zapfensystem).Wild/Leica centering system. Kern centering system.


g y ( p y )Source: www.geodirekt.de

g ySource: www.geodirekt.de

g ySource: www.swisstopo.ch

Reflector mountingReflector mounting

SBB Boltsmounting systems for monitoring purposesmounting systems for monitoring purposes

Typical mounting „L-supporter“ for monitoring.Source: www.goecke.de

Position reference

Height Reference

Levelling reference

Height Reference for trig. Height Determination

M8 thread

SBB B lt


SBB Bolts.Source: unkown

Observation Observation PillarsPillars

CoverCenteringCentering

Pillar ø ca. 35 cmProtection pipe ø ca. 55 cm

Water outletF d iFoundationø 150 cm


Support for Total StationsSupport for Total StationsSystem „Goecke“.

Console with total station, Mt. Terri Project.


Losatec mounting system in Gotthard Basetunnel near Faido.Source: Stephan Schütz

jSource: Stephan Schütz

Metrology, Instruments, Sensors, Beaconing,...

Documents

Transcript of Metrology, Instruments, Sensors, Beaconing,...