GeoRadar Division. GPR for Archeology and Cultural Heritage. GeoRadar Division. GPR Configuration for Archeology and Cultural Heritage Application

Size: px

Start display at page:

Download "GeoRadar Division. GPR for Archeology and Cultural Heritage. GeoRadar Division. GPR Configuration for Archeology and Cultural Heritage Application"

Anne Hudson
5 years ago
Views:

1 GeoRadar Division GPR Configuration for Archeology and Cultural Heritage Application

2 We believe that the Archaeological patrimony and the Cultural Heritage are one of the most important aspect of this patrimony. The problems related to the research and the management of the Archaeological sites and Cultural Heritage sites are growing every day, especially in the big urban areas, today projected into constantly urban expansion. Most of the cities are now developing in areas where, unfortunately, are located archaeological sites of relevant historic and artistic importance.

3 The orientation internationally is to develop a non-destructive archaeological approach to realize mapping of the sites and structures present in the subsoil without excavations.

Use of GPR in Archeological Surveys using GPR geophysical technique GPR Is an ideal technique for non invasive tool for site investigation To detect buried

4 Use of GPR in Archeological Surveys using GPR geophysical technique GPR Is an ideal technique for non invasive tool for site investigation To detect buried Anomalies For Site identification and excavation planning. Saving time & cost and significantly increasing capability. PPG/2008/00xx All rights reserved to IDS 4

7 DIVISIONE Principle of functionality Argomento della presentazione Logo di prodotto Antenna Delay time Position of the antenna 7

8 DIVISIONE Georadar technics Argomento della presentazione Logo di prodotto Position Delay Time 8

antenna Depth range & resolution are related to the radar

9 The Georadar transmits a very short pulse of e.m. energy into the material by a transmitting antenna. Energy reflected by discontinuities is captured by a receiving antenna Depth range & resolution are related to the radar frequency, transmitted power, host material e.m. properties and to the shape and characteristics of the targets PPG/2008/00xx All rights reserved to IDS 9

10 DIVISIONE Argomento della presentazione Logo di prodotto How an image is produced The round-trip transit time of the pulse emitted by the GPR and its reflection provide range information on the target

12 DIVISIONE low f Argomento della presentazione Logo di prodotto Relation frequency-wave length High wave lenght Bigger antenna size Lower resolution high f Smaller antenna size Major signal penetration Low wave lenght Minor signal penetration Bigger resolution 12

13 DIVISIONE Argomento della presentazione Logo di prodotto A Scan type visualization The quantity in x-axis is the time (delay) Multiple A scan views produce a B Scan i.e 2D representation PPG/2008/00xx All rights reserved to IDS 13

14 GeoRadar Division The multichannel visualization

15 The C Scan type visualization 15

17 Visualization in 3D utilises time slicing Slice depth depth cm cm Slice depth depth cm cm Slice depth depth cm cm Slice depth depth cm cm The data related to an area is elaborated with a specific processing (comprising the migration) In visualization, the user can slice the area investigated to different depths

18 DIVISIONE Argomento della presentazione GRED HD 3D : post processing software The GRED HD software comes with a 3D graphic interface. The software is able to show: Tomography (time slices), Radar scans parallel to the acquisition direction, Virtual Radar scans orthogonal to the acquisition direction 3D view. Logo di prodotto November 2008

20 Two Electrical Properties Of Importance To GPR Work Electrical conductivity (inverse of resistivity) σ is a measure of a material s ability to carry an electric current The value is primarily controlled by water content and/or clay content Higher conductivity makes radar signal penetration difficult Relative dielectric permittivity (Dielectric constant) Measures the capacity of a material to store charge when an electric field is applied The value ranges from 1 to 81 (1 = air, 81 = water); the value (for soils) is mainly controlled by water content Differences in dielectric properties between two adjacent materials through which the radar wave propagates will cause reflection of some of the radar energy back to the surface The strength of reflections is controlled by the contrast in the dielectric constants of the two adjacent materials. PPG/2008/00xx All rights reserved to IDS 20

21 Depth of investigation Decreases as: Electrical Conductivity Increases Water Content Increases Clay Content Increases Scattering Increases Conductive Contaminant Increases GPR user has no control over the above factors--these are site specific characteristics. Increases as: Antenna Frequency Decreases Transmitter Power Increases Receiver Sensitivity Increases GPR user has control over the above factors to some degree 21

22 Features of GPR antennas Center Sample Depth Typical Frequency (MHz) Applications (m) Range (ns) 80 Geologic MLF Geologic Geologic, Environmental Shallow Geology, Engineering, Environmental Shallow Geology, Engineering, Environmental, Archaeology 900 Concrete, Soils, Archaeology 22

23 Selection of better antennas DEPTH RANGE OF INTEREST PRIMARY ANTENNA SECOND CHOICES m (0-1.5 ft) 1000 MHz 900 MHz 0-1 m (0-3 ft) 900 MHz 500 MHz m (0-8 ft) 500 MHz 300 MHz 0-9 m (0-30 ft) 300 MHz 120, 100 MHz 0-20 m (0-60 ft) MLF (80, 40, 32, 20, 16 MHz) 0 - >20 m (0 - >60ft) MLF (80, 40, 32, 20, 16 MHz) 100 MHz 100 MHz 23

24 The grid of acquisition scans L axis 6 4 T Scans Orthogon al cartesian reference system 2 L Scans T axis 24

25 DIVISIONE Argomento della presentazione Logo di prodotto SINGLE ANTENNA 40cm 40cm 2m 40cm Uncomplete covering Low probability of detection Difficult compromise Complete covering Increasing of acquisition time 25

26 DIVISIONE Argomento della presentazione Logo di prodotto Increasing of performance using an array PFA= 10-1 Covering with array PD(%) antenna 2 antenne 3 antenne 4 antenne 26

Configuration for Archeology research: RIS MF Hi-Mod RIS MF Hi-Mod is a specialized system able to investigate big areas with a 3 D view of the subsoil with a high capability of resolution and

28 Configuration for Archeology research: RIS MF Hi-Mod RIS MF Hi-Mod is a specialized system able to investigate big areas with a 3 D view of the subsoil with a high capability of resolution and penetration depth. Thanks to the high capability of the radar and to the experience of the archaeologists is possible to know with very high level of confidence the buried underground objects and to plan the excavation activities. 4 dual frequency antennas (200 MHz and 600 MHz) 2 m wide Antenna Array for 3D mapping Modular design suited to urban environment and narrow passages High productivity post-processing SW CAD/GIS automatic rendering Data Base for rational storage of large quantities of data

29 MODULAR COMPOSITION and UPGRADABILITY CONFIGURATION MODEL ANTENNAS PICTURE UPGRADABILITY BASIC RIS MF Hi-Mod #1 1 INTERMEDIATE RIS MF Hi-Mod #2 2 or RIS MF Hi-Mod #3 3 FULL RIS MF Hi-Mod #4 4

DAD Fast Wawe Aluminium steering handle 2

reconfigurable Chain connection plug and play

30 DAD Fast Wawe Aluminium steering handle 2 Batteries Reconfigurable array structure All terrains High maneuverability Robust and light High penetration depth Easily mounted and reconfigurable Chain connection plug and play Fast Wave DAD: high stacking factor 4 dual-frequency antennas ( MHz)

31 IDS GPR available antennas 100 MHz antenna 2000 MHz antenna 25/40 MHz antenna

33 Post Processing Software: end results

35 DIVISIONE Testing Rovereto Field Argomento della presentazione Logo di prodotto The test area is a 1500 square meters wide trapezium. Many T and L scans were made to detect well known buried structures. July 2009 All rights reserved to IDS

DIVISIONE Argomento della presentazione GPR Tomography Results Depth: 0,7m. Looking at the tomography we easily detect some of the hidden targets (red circles).

36 DIVISIONE Argomento della presentazione GPR Tomography Results Depth: 0,7m. Looking at the tomography we easily detect some of the hidden targets (red circles). The green line represents an unsignaled pipe while the green box shows a couple of strong reflections of unknown origin. The final step of the survey is mapping our discoveries using a CAD interface. July 2009 All rights reserved to IDS Logo di prodotto

of the survey is mapping our discoveries using a

38 DIVISIONE Argomento della presentazione GPR Tomography Results Bonus Feature Depth: 0,3 m. An X-shaped pattern. It can be interpreted as some sort of biological track. July 2009 All rights reserved to IDS Logo di prodotto

39 GPR archeological research in Israel: Hark Karkom STRATIGRAPHIC CONTACT CAVITIES 100 MHz antenna

40 GPR archeological research in Italy: San Sebastiano church in Milan Cripta Centrale TOMOGRAPHIC MAP HYSTORICAL MAP

41 GeoRadar Division GPR archeological research in Italy (1/2): square of Miracles - Pisa

42 GPR archeological research in Italy (2/2): square of Miracles - Pisa Tomographic map An image of the hold excavation (1936).

44 DIVISIONE Argomento della presentazione Logo di prodotto GeoRadar Division GPR High Frequency Investigation for Structural Application

location of voids; Inspection of concrete thickness, integrity; 3D imaging of pre-tension and post-tension cables; Inspection and

45 Used Configuration: Aladdin System Description ALADDIN an advanced radar based sensor for Non-Destructive structural analysis Civil engineering & Cultural heritage applications 3D imaging of shallow and deep rebars in concrete; Inspection of concrete for location of voids; Inspection of concrete thickness, integrity; 3D imaging of pre-tension and post-tension cables; Inspection and analysis of old structures and monuments; Inspection of walls and floors for the location of pipes, objects, caches, etc.. June 2008

Standard Products ALADDIN Depth: 0.10m Depth: 0.

antenna combined with the patented Pad Survey Guide

be acquired in a single pass, detecting shallow and

compared to standard methods. Depth: 0.40m Depth: 0.

antenna can read the shallow targets (rebars), but

the FULL-POLAR antenna is able to identify both

46 Standard Products ALADDIN Depth: 0.10m Depth: 0.10m The SPECIAL FULL-POLAR highfrequency (2 GHz) antenna combined with the patented Pad Survey Guide (PSG) permit joint orthogonally polarized scans to be acquired in a single pass, detecting shallow and deep structures and halving acquisition time compared to standard methods. Depth: 0.40m Depth: 0.40m Longitudinal dipole Scan direction The standard antenna can read the shallow targets (rebars), but is not able to reveal the lower structures Instead, the FULL-POLAR antenna is able to identify both targets (shallow and deep) in just one scan. Transversal dipole June 2008

Direct results in the field by exporting data from K2 acquisition

48 DIVISIONE Argomento della presentazione Logo di prodotto GPR High Frequency investigation for structural application (1/4): GPR investigation on the structures of the Sao Paulo (Brasil) Metro line to evaluate: The presence and the spacing of the rebars into a pillar The presence and the spacing of the rebars and/or tendons Used Configuration: Aladdin System (2 GHz Bipolar antenna) Sao Paulo (Brasil) June 2008

structural application (2/4): Structural Application

49 DIVISIONE Argomento della presentazione Logo di prodotto GPR High Frequency investigation for structural application (2/4): Structural Application on the Sao Paulo (Brasil) Metro Line - Acquisition phase June 2008

spacing of the rebars 8 iron bars on horizontal side (depth 3cm 6 iron

50 DIVISIONE Argomento della presentazione Logo di prodotto GPR High Frequency investigation for structural application (3/4): Presence and spacing of the rebars 8 iron bars on horizontal side (depth 3cm 6 iron bars on vertical side (depth 5cm) Horizontal spacing between each rebar: 20-25cm June 2008

51 DIVISIONE Argomento della presentazione Logo di prodotto GPR High Frequency investigation for structural application (4/4): Presence and spacing of the rebars into the pillar 15 iron bars in vertical direction (depth 5 cm) 20 iron bars in horizontal direction around the pillar (depth 3cm) Double line of rebars. Horizontal spacing between each rebar: 10-20cm June 2008

52 DIVISIONE Argomento della presentazione Logo di prodotto GPR High Frequency investigation for structural application (1/3): GPR investigation, on the test site of the Roma Metro line to evaluate: The presence of the cavity behind the concrete layer Used Configuration: 900MHz and 2GHz antenna Rome, Italy June 2008

53 DIVISIONE Argomento della presentazione Logo di prodotto GPR High Frequency investigation for structural application (2/3): The test site on Rome Metro line - Acquisition phase Concrete layer Artificial cavity June 2008

structural application (3/3): Results Iron bars Limit

54 DIVISIONE Argomento della presentazione Logo di prodotto GPR High Frequency investigation for structural application (3/3): Results Iron bars Limit of the concrete layer Gap created by the artificial cavity June 2008

55 GPR research in Italy (1/2): Saint Pieter s square - Rome Aladdin San Bonaventura statue 14 longitudinal scans and 8 transversal scans 6 longitudinal scans on the base each 10 cm

56 GPR research in Italy (2/2): Saint Pieter s square - Rome San Bonaventura statue Different layers and cavity (red area) Scan 16 natural layers (depth: 25-30cm) Scan 16 - Cavity (depth: 24cm)

RIS Configuration for tunneling COMPONENTS:

Single or Multi Channel Control Unit (DAD 1CH

(frequency fro 200 MHz up to 2 GHz) or Array

58 RIS Configuration for tunneling COMPONENTS: Data Logger (PC Panasonic CF 19 or other PC) Single or Multi Channel Control Unit (DAD 1CH or DAD MCH) Antenna: Single Channel Antenna (frequency fro 200 MHz up to 2 GHz) or Array of antenna (TR600V-HF, High Frequency array). All IDS Antennas Survey kit. Data Logger: PC Panasonic CF MHz Antenna Data Logger: PC Hammerhead HF54 DAD-MCH Multi Channel Control Unit 1600 MHz Antenna All rights reserved to IDS 58

Type: Shielded Dipole Nominal Frequency: from

Dimensions (LxWxH): 43x37x20 cm 600-V MHz and

HF (2GHz) Antenna Dimensions (LxWxH): 13x12x8

Rain Proof (IP 65) Temperature: -40 C / 50 C

59 ANTENNA FEATURES TR H Antenna TR600V-900 Antenna TR600V-2GHz Array Antenna Type: Shielded Dipole Nominal Frequency: from 200 MHz up to 2 GHz 200, H MHz Antenna Dimensions (LxWxH): 43x37x20 cm 600-V MHz and 900 MHz Antenna Dimensions (LxWxH): 20x26x20 cm HF (2GHz) Antenna Dimensions (LxWxH): 13x12x8 cm Relative humidity: <90% (non-condensing) Rain Proof (IP 65) Temperature: -40 C / 50 C TRHF-2GHz Antenna N 2 TR600V Array All rights reserved to IDS 59

$line Genova-Ovada (Italy): Study of the fractures, stratigraphy and anomaly in the tunnel to evaluate the structure$ stability and the presence of area with a risk of water infiltration.

stability and the presence of area with a risk of water infiltration.

60 GPR investigation in a Tunnel along a rail track (1/2) Geotechnical application in the Gorsexio tunnel along the rail line Genova-Ovada (Italy): Study of the fractures, stratigraphy and anomaly in the tunnel to evaluate the structure stability and the presence of area with a risk of water infiltration. Used Configuration: RIS One with 200MHz and 600 MHz Antennas Gorsexio tunnel along the rail line Genova-Ovada ( Italy) Gorsexio Tunnel Acquisition phase All rights reserved to IDS 60

Fracture Fractured area with water Gorsexio

61 GPR investigation in a Tunnel along a rail track (2/2) Internal transition 2 different layers of bricks Contact between tunnel structure and bedrock 600 MHz Results Fracture Fracture Fractured area with water Gorsexio Tunnel Acquisition phase 200 MHz Results All rights reserved to IDS 61

62 IBIS FS Interferometry system for displacement monitoring of historical structures Remote static and dynamic monitoring of structures. IBIS-FS is able to remotely monitor for static applications such as structural load testing, structural displacement and collapse hazards as well as cultural heritage preservation without needing direct access to the site or the use of any invasive equipment. It is also able to perform dynamic monitoring applications including structural resonance frequency measurements, structural modal shape analysis and real time deformation monitoring. PPG/2008/00xx All rights reserved to IDS 62

Remote sensing: Real-time remote sensing at up to 1 km with from the monitored structure. Accurate measurements: Measures displacements of as little as 0.

63 Remote sensing: Real-time remote sensing at up to 1 km with from the monitored structure. Accurate measurements: Measures displacements of as little as 0.01mm and up to 0,5 Km. No standard instrument can achieve such accuracy. Sampling: Structural vibration sampling up to 200 Hz. PPG/2008/00xx All rights reserved to IDS 63

The system can be measure 10mm displacement in 0.005s Or the system can measure 100mm in 0.

64 The system can be measure 10mm displacement in 0.005s Or the system can measure 100mm in 200Hz Or higher, depending on the monitoring time (1 minutes or several minutes) and the deformation velocity of the monitored structure PPG/2008/00xx All rights reserved to IDS 64

GPR SURVEY METHOD. Ground probing radar

GPR SURVEY METHOD. Ground probing radar The ground penetrating radar (GPR - Ground Probing Radar) is a geophysical method used to investigate the near surface underground. Thanks to its high degree of resolution, the GPR is the most effective