college college of dean: dr. karl stevens geomatic ... · introduction •“geomatics...

COLLEGE

COLLEGE OFENGINEERING & COMPUTER SCIENCE

DEAN: DR. KARL STEVENSDEAN: DR. KARL STEVENSASSOCIATE DEAN: DR. MOHAMMAD ILYAS

GEOMATIC ENGINEERING PROGRAM

INTERIM PROGRAM DIRECTOR: DR. DON LEONE P.E.

STAFF & FUTURE

ENGINEERS, SURVEYORS, ARCHITECTS&

SCIENTISTS

♦ SUE. RT and Geomatics Witten Technologies, Inc. R&D

(617) 236‐7103 ♦ http://www.wittentech.com

Nov. 13th, 2008 ♦ 2

SCIENTISTS

SUE, RT and Geomatics,

How do Subsurface Utility Engineering (SUE) and modern geophysical imaging techniq es s ch as Radar Tomograph (RT) relate to Geomatics?imaging techniques such as Radar Tomography (RT) relate to Geomatics?

Ralf Birken, Ph.D.Chief Scientist



Nov. 13th, 2008 ♦ 3

Chief Scientist

O U T L I N E

• IntroductionS b f Utilit E i i (SUE) d “ t bli h d” G h i• Subsurface Utility Engineering (SUE) and “established” Geophysics

• Modern Array-based Land-based Geophysical Methods– Radar TomographyRadar Tomography

• Concepts, Systems and Methodology, and Case Histories

– Electromagnetic Induction Arrays• Concepts, Systems and Methodology, and Case HistoriesConcepts, Systems and Methodology, and Case Histories

• SUE and the Impact of Geophysical Arrays– Legislation and Certification

• Summary



Nov. 13th, 2008 ♦ 4

Introduction

• “Geomatics Engineering”i d di i li hi h i t t i iti d li tis– is a modern discipline, which integrates acquisition, modeling, analysis, and management of spatially referenced data, i.e. data identified according to their locations. Based on the scientific f k f d it t t i l i i b d ga

ry.ca/abou

t/wha

framework of geodesy, it uses terrestrial, marine, airborne, and satellite-based sensors to acquire spatial and other data. It includes the process of transforming spatially referenced data f diff t i t i f ti t ith w

w.geo

matics.ucalg

from different sources into common information systems with well-defined accuracy characteristics."

• “Subsurface Geomatics” ?

http://w

w

Subsurface Geomatics ?– How do you acquire accurate surveying data of subsurface

features ?Wh t i t ?



Nov. 13th, 2008 ♦ 5

– What accuracies can you expect ?

Subsurface Utility Engineering (SUE) and “established” Geophysics“established” Geophysics

Greg JeffriesVice President



Nov. 13th, 2008 ♦ 6

SUE and “established” Geophysics

• Quality Level D (QL D):I f ti d i d f i ti d l Information derived from existing records or oral recollections.

• Quality Level C (QL C):Information obtained by surveying and plotting visible Information obtained by surveying and plotting visible above-ground utility features and by using professional judgment in correlating this information to QL D information.judgment in correlating this information to QL D information.

B d CI/ASCE 38 02 t d d d b A h



Nov. 13th, 2008 ♦ 7

Based on CI/ASCE 38-02 standards and summary by Anspach


• Quality Level B (QL B):I f ti bt i d th h th li ti f i t Information obtained through the application of appropriate surface geophysical methods to determine the existence and approximate horizontal position of subsurface utilities and approximate horizontal position of subsurface utilities.

QL B data should be reproducible by surface geophysics at Q p y g p yany point of their depiction. This information is surveyed to applicable tolerances defined by the project and reduced onto plan documents.

B d CI/ASCE 38 02 t d d d b A h



Nov. 13th, 2008 ♦ 8



• Quality Level A (QL A):Precise horizontal and vertical location of utilities obtained by the actual exposure (or verification of previously exposed and surveyed utilities) and subsequent measurement of subsurface utilities, usually at a specific point. Minimally intrusive excavation equipment is typically used to minimize the potential for utility damage A precise used to minimize the potential for utility damage. A precise horizontal and vertical location as well as other utility attributes is shown on plan documents. Accuracy is attributes is shown on plan documents. Accuracy is typically set at 15mm vertical, and to applicable horizontal survey and mapping.



Nov. 13th, 2008 ♦ 9



• Commonly used geophysical methods:– Pipe and cable locators– Terrain conductivity meters

Metal detectors– Metal detectors– Ground Penetrating Radar (GPR)– Magnetic methodsMagnetic methods– Acoustic Methods– Optical systemsp y



Nov. 13th, 2008 ♦ 10


• Common features:– Typically handheld or pushcart-based single channel systems– Typically no geo-referenced data recording

Sparse non continuous coverage– Sparse non-continuous coverage

Bi b t QL B d QL A f • Big gap between QL B and QL A as far as:– Cost

Accuracy (Horizontal and Vertical)– Accuracy (Horizontal and Vertical)– Both lack continuous Coverage



Nov. 13th, 2008 ♦ 11


• Suggestion to narrow gap between QL B and QL A using:A b d S f G h i l M th d– Array-based Surface Geophysical Methods

• As far as: QL AHigherAs far as:– Continuous

CoverageSUE Quality Levels

QL‐A

QL‐B

Higher

– Horizontal andVertical Position

– Cost versus Risk

COSTQL‐C

QL B

– Reusable geo-referenced digital data

QL‐D

Lower i h



Nov. 13th, 2008 ♦ 12

digital data RISKLower Higher

References

• American Society of Civil Engineers (2002). C/I ASCE 38-02 St d d G id li f th C ll ti d D i ti f 02, Standard Guideline for the Collection and Depiction of Existing Subsurface Utility Data. Reston, VA.A h J H 2002 (?) U d d tilit it i • Anspach, J.H., 2002 (?), Underground utility security issues at critical facilities: ?, 5 pages.



Nov. 13th, 2008 ♦ 13

Modern Array-based Land-based Geophysical Methods

• Multi-channel geophysical systems• Deployed through vehicle (some even within traffic flow)• Movement tracked through survey-grade positioning system• Create accurate geo-referenced digital data sets• Able to cover large areas efficiently with dense continuous data

coverage• Allow more advanced methods of data interpretationp• Option to combine multiple arrays in single data collection effort• Surveyor certified accuracy and final maps



Nov. 13th, 2008 ♦ 14

Surveyor certified accuracy and final maps

Radar Tomography (RT)g p y ( )

Concept



Nov. 13th, 2008 ♦ 15

Common 2D GPR Survey Grids

2 feet or more between profiles

4 inches or more between t i ( t ti )

Rarely uses accurate geometry control regarding line spacing and direction

triggers (stations)



Nov. 13th, 2008 ♦ 16

Rarely uses accurate geometry control, regarding line spacing and direction

GPR Section with Point Reflectors

GPR is also looking to the sideT T T T T T T T TR R R R R R R R

Note:Note:Point reflectors and pipes perpendicular to the profile appear the same in 2D



Nov. 13th, 2008 ♦ 17

appear the same in 2D GPR section

Array GPR Advantages - I

Efficiency in data collection, especially when survey area large(>40 000 sqft) and target small requiring small profile spacing(>40,000 sqft) and target small requiring small profile spacing

Standard GPR System1 Tx‐Rx channel

Array GPR System16 Tx‐Rx channels

12.5 cm swath of coverage in

one profile

2.0 m swath of coverage in

one profile



Nov. 13th, 2008 ♦ 18

Transmitting antenna (Tx) Receiving antenna (Rx)

Array GPR Advantages - II

A dense grid of multiple 2D GPR profiles allows synthetic aperture focusing to create a stack of image slices at different depths to create a 3D image below ground.g p g g

Dense 2D grid becomes 3D GPR gridwhen profile spacing close to station spacing

Dep

thD



Nov. 13th, 2008 ♦ 19

Goal: One GPR trace every 5 inches or less in in-line and cross-profile direction


Systems and Methodology



Nov. 13th, 2008 ♦ 20

Radar TomographyRadar Tomography(Ground-Penetrating Imaging Radar)

Joint development of Joint development of

Witten Technologies Inc., Malå Geoscience, ConEdison

Schlumberger, EPRI, GTI (formerly GRI)



Nov. 13th, 2008 ♦ 21

Radar Tomography (RT)

RT: A GPR survey or system that combines efficient radarRT: A GPR survey or system that combines efficient radar surveying with precise positioning control and advanced signal processing allowing the creation of high resolution 3D radar images of the subsurface onhigh-resolution 3D radar images of the subsurface on a large-scale.

Meaning:“precise positioning” = centimeters“large scale” = surveys covering thousands of square meterslarge-scale = surveys covering thousands of square meters“high-resolution” = resolution of centimeters



Nov. 13th, 2008 ♦ 22

Radar Tomography (RT) Methodology

R d ARadar Arrays

Survey-grade

Continues 3D Radar Images

prism

Survey-gradePositioning Accurate Certified Utility Maps



Nov. 13th, 2008 ♦ 23

laser theodolite

Please wait for movie to start

J R i 09 ith i t t t k 2Jax_Region_09_with_pictometry_tweak-2.mov



Nov. 13th, 2008 ♦ 24

CART Imaging Systemg g yComputer‐Assisted Radar Tomography

Total daily coverage:40,000 – 80,000 sqft

Spatial resolution (16 channel mode): Spatial resolution (16 channel mode): ~ 5” channel or cross-line spacing~ 4” trace or in-line spacing

M i D i i S d 5 i/hRadar component of CART Imaging System



Nov. 13th, 2008 ♦ 25

Maximum Driving Speed: 5 mi/hr is manufactured by Malå Geoscience

CART Schematic

400 and 200 MHz antennas



Nov. 13th, 2008 ♦ 26

Operational Specifications in Words

• Depth of penetration is 4 to 6 ft in most sandy-clay soils (8 t 12 ft i d il ) it ifi ti(8 to 12 ft in sandy soils), very site specific, conservative

• Depth accuracy is about 5% (i.e., ± 3 in. over 5 ft)• Horizontal accuracy is about 1% from mapped surface

features such as manhole covers or curb linesR l ti f b f bj t i b t 3 t 4 i• Resolution of subsurface objects is about 3 to 4 in.– Objects as small as 1-in. can be seen at shallow depths– Resolution degrades with depth at rate of about 1 in/ft

• Typically certified to ± 6 in. in all 3 coordinates



Nov. 13th, 2008 ♦ 27

Positioning System I – Robotic Laser

• Precise geometry control provided by a self-tracking laser theodolite(robotic total station) locking on to a 360 degree prism(robotic total station) locking on to a 360 degree prism

• 3D accuracy of ±[1 ppm + 1 mm]; for example, ±2 mm in 1 km• Range of 2 km• Range of 2 km• Self-tracking, accurate

reading every 6 sprism

(faster ones available)• Standard technology for

construction surveyingconstruction surveying• Survey-grade,

can be certified by laser theodolite



Nov. 13th, 2008 ♦ 28

professional surveyorManufactured by Geodimeter (now Trimble)

Positioning System II - GPS

• Precise geometry control provided by RTK GPS system consisting of by RTK GPS system consisting of base station and rover

• Accurate reading every secondg y• 7.2 km/h (2 m/s) recommended

speed (one data point every 2 m)S ifi d A ith ffi i t • Specified Accuracy with sufficient Satellite coverage:– Horizontal: 10 mm + 1 ppmpp– Vertical: 15 mm + 1 ppm

• Survey-grade, can be certified by professional surveyor♦ SUE. RT and Geomatics Witten Technologies, Inc. R&D


Nov. 13th, 2008 ♦ 29

professional surveyorManufactured by TOPCON (Hiper+ gr-2100)

Processing, Integration, Visualization

• The radar data are processed into geo-referenced seamless 3D radar imagesimages

• Those are interpreted for pipes• With the help of complementaryWith the help of complementary

information gathered with traditional SUE methods theutility types were identifiedutility types were identified

• The clients receive certified CADmaps in plan and profile showingp p p gthe 3D location of each pipecolored coded by utility



Nov. 13th, 2008 ♦ 30

• Autodesk, Microstation or ArcGIS

Please wait for example mapsp p

03_2006_Laura_St_Jak_JEA_Phz1.pdf



Nov. 13th, 2008 ♦ 31

Corrected CAD Maps

telephone duct banksoff by ten feet of more

lines not presenton original map

10 ft water line offb l f t

W

by several feet

Colored lines show utility locations according to available maps.

Black lines show actual locations (of selected utilities) determined



Nov. 13th, 2008 ♦ 32Church St

Black lines show actual locations (of selected utilities) determined by radar tomography.


Case Histories



Nov. 13th, 2008 ♦ 33


Example from theLower Manhattan Radar Projectj



Nov. 13th, 2008 ♦ 34

CART Surveys Near WTC

West St.Survey Area



Nov. 13th, 2008 ♦ 35

Areas surveyed in August 2001Areas surveyed from December 2001 – February 8th 2002

Lower Manhattan Radar ProjectLower Manhattan Radar ProjectHelp in planning reconstruction of the utility network of Lower ManhattanHelp in planning reconstruction of the utility network of Lower Manhattan

view north along West St view northeast corner of West and Liberty



Nov. 13th, 2008 ♦ 36

view north along West St view northeast corner of West and Liberty

20 ft

roadbed joints

s rface feat res

damaged zonewash outs?

RADAR IMAGE

surface featuresmanhole and valve covers



Nov. 13th, 2008 ♦ 37

RADAR IMAGE2 inches below street level

d h d f db d j i t

20 ft

radar shadow of roadbed joints

A

tops of service boxes

RADAR IMAGE



Nov. 13th, 2008 ♦ 38


A

fradar shadow of roadbed joints

20 ft

gas

electric

RADAR IMAGE



Nov. 13th, 2008 ♦ 39


20 ft

water

RADAR IMAGE



Nov. 13th, 2008 ♦ 40


Please wait for movie to start



Nov. 13th, 2008 ♦ 41

RT – GIS Overview West Street

New York CityNew York City Orthophoto basemap -State Plane (NAD 83) f t



Nov. 13th, 2008 ♦ 42

(NAD 83) feet



Nov. 13th, 2008 ♦ 43


Case HistoryNYC, Cathedral Parkway ProjectNYC, Cathedral Parkway Project



Nov. 13th, 2008 ♦ 44

Cathedral Parkway Project“C t ti I t f ”“Construction Interference”

Determine if installation of footings for a new walkway along Central Park would require relocation of a high power feeder line



Nov. 13th, 2008 ♦ 45



Nov. 13th, 2008 ♦ 46

Contin o s ( i ) i i t t iview #1 east Continuous coverage (mapping) is important in projects that involve long section of utility lines

along walkway

view #2 northeast

DOUGLAS CIRCLE

#1

#2 Views of oil-o-static (138kV) lines under Cathedral Parkway near Douglas Circle



Nov. 13th, 2008 ♦ 47

FRAWLEY CIRCLE

Line pair is normally at 36 inches depth except for a short section where it rises to 24 inches (below grade)



Nov. 13th, 2008 ♦ 48

Map view of lines – color indicates depth

Cathedral Parkway

• Mapped ~2000 ft of high-voltage electrical feeder lines over entire l th f l d t tilength of planned construction

• Cost of $15k (30 000 sq ft at $0.50/sq ft) recovered in fewer test pits needed to verify that construction plan would not affect the linesneeded to verify that construction plan would not affect the lines– Number of test pits reduced from 20 (or more) to 5– Cost of a test pit in NYC is about $800 to $3000Cost of a test pit in NYC is about $800 to $3000

• “Cost Leverage”: Reduced risk of having to relocate the lines (a cost of $1 to $3 million) if original maps were inaccurate



Nov. 13th, 2008 ♦ 49

Electromagnetic Induction Arrayg y

Concepts



Nov. 13th, 2008 ♦ 50

Other Transaction Agreement #DTRS56-02-T-0005Digital Mapping of Buried Pipelines with a Dual-Array Systemg pp g p y y

R&D Project funded byWitten Technologies

C lid t d Edi C f N Y kConsolidated Edison Company of New YorkU.S. Department of Transportation Research and Special Projects Administration

With technical contributions from EMI (a division of Schlumberger)EMI (a division of Schlumberger)

Regional Water Authority of South Central ConnecticutSeknion



Nov. 13th, 2008 ♦ 51

October 2002 – December 2004

Mobile platform for urban mapping



Nov. 13th, 2008 ♦ 52

Arrayed Induction Receivers (AIR) System

MethodologyMethodologyElectromagnetic Induction Array

Accurate Utility MapsAccurate Utility Maps

ElectromagneticField Map



Nov. 13th, 2008 ♦ 53

Field Map


Systems and Methodology



Nov. 13th, 2008 ♦ 54

Arrayed Induction Receiver (AIR) System• Array of 16 broadband vector

magnetic field sensors (induction coils)

• Broadband frequency response– Flat from 1 to 80 kHz

• Low noise level– 0.0005 nT @ 1 kHz– 0.0001 nT @ 10 kHz@

• Small package– 15 cm3, about 3 kg

• Built by EMI (Schlumberger)Built by EMI (Schlumberger)• Simultaneous data acquisition of

all 48 channels



Nov. 13th, 2008 ♦ 55

Survey-grade Positioning System

PRISM

BASE STATION

• System uses laser theodolite (robotic total station) for survey-grade positioning– 3D accuracy of ±[1 ppm + 1 mm]; for example, ±2 mm in 1 km

Range of 2 km– Range of 2 km– Self-tracking of 360 deg. prism, accurate reading every 6 s– Standard technology for construction surveying– Map surface features for local reference map

• Alternatively use survey grade GPS



Nov. 13th, 2008 ♦ 56

• Alternatively use survey-grade GPS

EM Source Options

Current injection (“clamp-on”)• Current injected directly onto pipe by galvanic Current injected directly onto pipe by galvanic

leads or toroidal clamp• Frequencies from 500 Hz to 85 kHz

Remote induction (“on-board”)• Three orthogonal coils of 0.7 m dia. • Moment of 5 at 1 kHz • Frequencies from 500 Hz to 50 kHz• Reference signal for phase detectionReference signal for phase detection

Existing signals



Nov. 13th, 2008 ♦ 57

• 60 Hz signals on power lines


Case Histories



Nov. 13th, 2008 ♦ 58

83 kHz Lower Hx EM Field Data

‐ 0.66m



Nov. 13th, 2008 ♦ 59

39 kHz Total Horizontal EM Field

‐ 3.6m

‐ 3.3m



Nov. 13th, 2008 ♦ 60

8.9 kHz Total Horizontal EM Field

‐ 3.3m4 9m‐ 4.9m



Nov. 13th, 2008 ♦ 61

Dipping Power Line



Nov. 13th, 2008 ♦ 62

Dipping Power Line



Nov. 13th, 2008 ♦ 63

EM Complementing Radar



Nov. 13th, 2008 ♦ 64

Maps and Located Pipes in GIS

• EM Pipe Picks (gray lines),p (g y ),Radar Pipe Picks (color-codedby depth are superimposed on65 kHz horizontal magnetic field mapand 200 MHz Depth Slice at 30”and 200 MHz Depth Slice at 30

• Surface features (symbols) and the curbs in light gray



Nov. 13th, 2008 ♦ 65

• Map was composed in ARCGIS

Qualitative Pipe Picks Visualized in GIS

• Pipe Picks (gray lines) Pipe Picks (gray lines) are superimposed on 32 kHz horizontal

ti fi ld d t magnetic field data map and high-resolution aerial photoresolution aerial photo(courtesy of RWA)

• Map was composed in ARCGIS



Nov. 13th, 2008 ♦ 66

ARCGIS

Another GIS Example



Nov. 13th, 2008 ♦ 67

Subsurface Utility Engineering (SUE)and the Impact of Geophysical Arraysand the Impact of Geophysical Arrays



Nov. 13th, 2008 ♦ 68

SUE and the Impact of Geophysical Arrays

• Suggestion to narrow gap between QL B and QL A using:A b d S f G h i l M th d– Array-based Surface Geophysical Methods

• As far as: QL AHigherAs far as:– Continuous

CoverageSUE Quality Levels

QL‐A

QL‐B

Higher

– Horizontal andVertical Position

– Cost versus Risk

COSTQL‐C

QL B

– Reusable geo-referenced digital data

QL‐D

Lower i h



Nov. 13th, 2008 ♦ 69

digital data RISKLower Higher

SUE and the Impact of Geophysical Arrays

• SUE (QL D, QL C, and QL B) combined with geophysical array technologies (especially RT) have the following advantages:technologies (especially RT) have the following advantages:– Horizontal and Vertical Position of Utilities

• typically certified to within 6 inches by WTI professional land surveyor– Provide continuous coverage throughout area of interestProvide continuous coverage throughout area of interest– Cost less than exposure (QL A), more than QL B– Risk lower than QL B, almost QL A

Reusable geo referenced digital data improving project design– Reusable geo-referenced digital data improving project design– Better-informed more efficient Design– Reduces number of exposures (e.g. can guide vacuum excavation)

Construction 14% cost reduction $4 62/$1 ROI*– Construction – 14% cost reduction, $4.62/$1 ROI*• Reduced conflict = fewer change orders• Reduced damage = increased safety• Faster completion = reduced public nuisance• Reduced risk = lower bids



Nov. 13th, 2008 ♦ 70

• Reduced risk = lower bids

Taking advantage of these new technologies'

• Professional Surveyors certifying resultsSt SUE/”B t P ti ” d t (i diti f it)• Stronger SUE/”Best Practice” mandates (i.e. condition of permit)

• ROW owners make Project Owners bear the cost of ROW entry• Accurate Information AT THE BID: “squeeze the risk”• Accurate Information AT THE BID: squeeze the risk• FDOT:



Nov. 13th, 2008 ♦ 71

S U M M A R Y 1

• Array-based geophysical systems are changing SUEASCE 38 02 itt l ki i t i i t id li– ASCE 38-02 committee looking into revising current guidelines

– FDOT in final step of adopting RT as one of the best practices to be used for certain larger projects

• Combination of SUE, RT, QL D, QL C, QL B and reduced use of exposures (limited QL A) may proof to be best way to negotiate cost and riskto negotiate cost and risk

• Recommend to:– learn and teach about these emerging technologies– learn and teach about these emerging technologies– test and use them in projects for value and cost savings

throughout overall project



Nov. 13th, 2008 ♦ 72

S U M M A R Y 2

• Commercial Radar Tomography (RT) Services using the CART Imaging System are offered since early 2001

• Deliverables include CAD Microstation or GIS subsurface utility • Deliverables include CAD, Microstation, or GIS subsurface utility maps in 3D located with RT

• Surveyed several Million of square-feet over the past 7 years

• Electromagnetic Induction Array Prototype available for special project to locate deeper conductive utilities



Nov. 13th, 2008 ♦ 73

project to locate deeper conductive utilities

WITTEN TECHNOLOGIES, INC.Research & Development

35 M df d St t S it 30635 Medford Street, Suite 306Somerville, MA 02143

www.wittentech.com ● +1 617 236 7103 ● [email protected]



Nov. 13th, 2008 ♦ 74

© WITTEN TECHNOLOGIES, INC. 2008. All rights reserved.

college college of dean: dr. karl stevens geomatic ... · introduction •“geomatics...

Documents