Investigating the Applicability of

Standard Software Packages for Laser

Scanner Based Deformation Analyses

FIG Working Week 2017

01.06.2017

Christoph Holst, Berit Schmitz, Heiner

Kuhlmann

University of Bonn

Institute of Geodesy and

Geoinformation

Presented at th

e FIG W

orking Week 2017,

May 29 - June 2, 2

017 in Helsinki, F

inland

Congruency test

1. Differences between corresponding points

2. Stochastic model

Heiner Kuhlmann, Laser Scanner Based Deformation Analysis Folie 2

Point based deformation analysis

01.06.2017

www.leica-geosystems.com

𝑇 =𝒅𝑇𝑸𝑑𝑑

−1𝒅/ℎ

𝑠02

≥ 𝐹ℎ,𝑓,1−𝛼

1. Corresponding points ?

• One possiblity: Point cloud comparison

2. Stochastic model ?

• Difficult!

• Many influencing factors: misconstruction of laser scanner, incidence

angle, reflectivity/material/color of surface

=> In practice:

Heiner Kuhlmann, Laser Scanner Based Deformation Analysis Folie 3

TLS-based deformation analysis

01.06.2017

www.leica-geosystems.com

𝑇 =𝒅𝑇𝑸𝑑𝑑

−1𝒅/ℎ

𝑠02

≥ 𝐹ℎ,𝑓,1−𝛼

Possibilities implemented in standard software

(e.g. 3DReshaper, CloudCompare, Geomagic Studio/Control)

• Cloud to cloud comparison (C2C)

• Cloud to mesh comparison (C2M)

• Mesh to mesh comparsion (M2M)

• Multiscale model to model cloud comparison (M3C2)

Heiner Kuhlmann, Laser Scanner Based Deformation Analysis Folie 4

Point cloud comparison

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Reduction

of random

errors

Is these point cloud comparison applicable

for geodetic deformation analysis?

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Heiner Kuhlmann, Laser Scanner Based Deformation Analysis Folie 6

Case 1: Out-of-plane shape deformation

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blue: epoch 1

green: epoch 2

• Yes: Large differences where shape is deformed

Heiner Kuhlmann, Laser Scanner Based Deformation Analysis Folie 7

Case 1: Out-of-plane shape deformation

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Heiner Kuhlmann, Laser Scanner Based Deformation Analysis Folie 8

Case 2: In-plane rigid body movement

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• No: Large differences only at high surface curvature

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Case 2: In-plane rigid body movement

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• Wooden panel

• Water dam

Heiner Kuhlmann, Laser Scanner Based Deformation Analysis Folie 10

Two examples in paper

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Heiner Kuhlmann, Laser Scanner Based Deformation Analysis Folie 11

M3C2 (CloudCompare)

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[m]

Shape deformation of 6 mm to water side

Leica P20, 2 epochs: march and june 2016

• At TLS-based deformation analyses, no corresponding

points between epochs

• Detection of „deformations“ / differences by point cloud

comparison is possible

• Usefulness of point cloud comparison depends on direction

of deformation (in-plane or out-of-plane)

• No stochstic model, no significance range

Heiner Kuhlmann, Laser Scanner Based Deformation Analysis Folie 12

Conclusion

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Thanks for your attention!

Heiner Kuhlmann, Laser Scanner Based Deformation Analysis Folie 13 01.06.2017

Heiner Kuhlmann, Laser Scanner Based Deformation Analysis Folie 14

Example 1: Deformation wooden panel

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Heiner Kuhlmann, Laser Scanner Based Deformation Analysis Folie 15

Out-of-plane shape deformation

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Deformation of 23 mm

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C2M (Geomagic Control)

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[m]

Deformation of

about 23 mm visible!

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In-plane rigid body movement

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Translation and rotation of about 30…50 mm

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M2M (Geomagic Control)

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[m]

15 mm = Distance to wall

Moved area

Rigid body movement of 30…50 mm

not visible in results

• 3 stations

• 2 epochs

• Registration by targets

Heiner Kuhlmann, Laser Scanner Based Deformation Analysis Folie 19

Example 2: Deformation water dam

01.06.2017

AVN 6/2016

• Holst, Neuner, Wieser, Wunderlich, Kuhlmann: Calibration of

Terrestrial Laser Scanners

• Kauker, Holst, Schwieger, Kuhlmann, Schön: Spatio-Temporal

Correlations of Terrestrial Laser Scanning

• Wujanz, Holst, Neitzel, Kuhlmann, Niemeier, Schwieger: Survey

Configuration for Terrestrial Laser Scanning

AVN 11/2016

• Neuner, Holst, Kuhlmann: Overview on Current Modelling Strategies

of Point Clouds for Deformation Analysis

• Wunderlich, Niemeier, Wujanz, Holst, Neitzel, Kuhlmann: Areal

Deformation Analysis from Point Clouds – the Challenge

• Bureick, Neuner, Harmening, Neumann: Curve- and Surface-

Approximation of 3D-point clouds

Heiner Kuhlmann, Laser Scanner Based Deformation Analysis Folie 20

2 special issues in avn

01.06.2017