HAL Id: hal-01615713
https://hal.archives-ouvertes.fr/hal-01615713
Submitted on 12 Oct 2017
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Parametric pipe detection on the urban site Sense-City
using Ground-Penetrating Radar (GPR)
Florence Sagnard, Christophe Norgeot, Xavier Derobert, Vincent Baltazart,
Erick Merliot, François Derkx, Bérengère Lebental
To cite this version:
Florence Sagnard, Christophe Norgeot, Xavier Derobert, Vincent Baltazart, Erick Merliot, et al..
Parametric pipe detection on the urban site Sense-City using Ground-Penetrating Radar (GPR).
EGU European Geosciences Union General Assembly 2016, Apr 2016, Vienna, Austria. EGU
-European Geosciences Union General Assembly 2016, 1p, 2016. �hal-01615713�
www.
ifsttar
.fr
(b) depth 21.8 cm
T2
T6
(a) depth 15 cm
Objectives
-
Mapping the underground in a urban landscape with a non-destructive technique
using electromagnetic waves to detect
dielectric discontinuities
- Parametric detection
of dielectric and conductive utilities with relative small diameters buried in different types of soils
(nature, composition, moisture content) using
ground-coupled
georadars
at several frequencies
in the band
[0.3;4] GHz
- Development of signal and image processing techniques
for clutter removal, hyperbola detection and fitting, object and
soil characterization
Experiments in the test site Sense-city
Measurements in the pipe area
Interpretation using migration
Parametric pipe detection on the urban site Sense-City
using Ground-Penetrating Radar (GPR)
F. Sagnard
1
, Ch. Norgeot
2
, X. Derobert
1
, V. Baltazart
1
, E. Merliot
1
, F. Derkx
1
, B. Lebental
1
1
COSYS, University Paris-Est, Champs-sur-Marne, France
2
MDS, Paris, France
y (mm)
transmitter
receiver
0
~32 cm
~104 cm
~173 cm
~204 cm
70 cm
20 cm
~320 cm
~386.5 cm
~396.5 cm
T1
T2
T3
T4
T5
T6
30 cm
70 cm
d1=6.3 cm
20 cm
20 cm
d2=6 cm
30 cm
PVC air
hollow
metal
30 cm
50 cm
PVC air
d1=6.3 cm
12 cm
10 cm
PVC
air/water
PVC air
PVC air
4.5 cm
20 cm
reference
A cut view of the pipe zone
(e) depth 33.4 cm
T4
Migration 3D at 800 MHz
(
e
’=12.75)
• Images of the pipe zone using 3 different GPR systems (SIR 3000, Utility scan with 2
frequencies, radar FMCW) at the following nominal frequencies :
− 500 MHz, 900 MHz, 1600 MHz
− 300 et 800 MHz (double frequencies)
− [50 MHz;4 GHz] (FMCW, 2 polarizations)
• T5 at depth 54.5 cm : air-filled not detected in the polarization TM, water-filled better
detected in the polarization
• 900 MHz appears the best frequency in the compromise between resolution and
penetration
Sub-surface probing using GPR
Mapping the urban underground
zone with buried
objects
General view of the mini-city test bed
area
w
ith
ou
t
ob
jects
area
w
ith
ob
jects
4000
m
5000
m
grass
asphalt
central recording line
area with pipes
area with blades
central recording line
sidewalk
Top views
20 cm
19 cm
30 cm
20 cm
10 cm
20 cm
50 cm
30 cm
20 cm
10 cm
15 cm
1 horizontal
conductor
1 vertical
conductor
dielectric foam
dielectric foam
dielectric foam
trench only
trench only
conductor
PVC
PVC
PVC
PVC
T1
T6
T1
T6
Distribution of the buried pipes/blades
10 cm
2 ou 3 cm
1 cm
5 cm
6.3 cm PVC
6 cm conductor
4.5 cm
8 cm
Geotextile
(thin discontinuity)
22 cm
asphalt
backfill/cement
natural soil
natural soil
Layer 1
Layer 2
Layer 3
Layer 4
z=0
Structure of the subsurface
Buried objects
Commercial GPR systems
operating in the time domain
500 MHz (SIR 3000)
Double frequency 300-800 MHz
(UtilityScan DF)
Laboratory-made GPR system
operating in the frequency domain
(FMCW)
Polarization TM
E
Polarization TE
E
Measurements in the time domain
Layer 1
Layer 2
0.
6
ns
1.2 ns
geotextile
Soil characterization at 900 MHz
(with linear gain,
D
y~1 cm)
Layer 3b
Layer 3
Layer 4
T6
T3
T1 T2 T5
16.3
0.8
4
6.7
17.2
geotextile
layer
0.6
2
6.2
14.5
T4
Pipe radargram (with linear gain)
500 MHz (
D
y~1 cm)
900 MHz
T6
T3
T1
T2
T4
T5
16.
3
0.8
7
4.3
6
2.9
geotextile
layer
Measurements in the frequency domain
T3
T2
T4
T6
T1
geotextile
layer
air
filled
metal
metal
T3
T2
air wave
T6
T4
air filled
geotextile
layer
Radargrams at 900 MHz (with gain)
TE polarization (
D
y=4 cm)
TM polarization
water-filled
water-filled
air-filled
air-filled
800 MHz (with gain
)
800 MHz (time zero correction
and migration
e
’=12.75)
T1
T2
T3
T4
T5
T6
400
400
T1
T2
T3
T4
T5
T6
geotextile
layer
(d) depth 24.8 cm
T3
T1
(c) depth 23.6 cm
(f) depth 49.4 cm
T5
e
’=4
e
’=6.9
e
’=36
