Radiometry of wet surfaces

Directed by Lionel SIMONOT

Description

As everyone can see every day, many objects or materials change their appearance when they get wet. Most of the time, the object becomes more translucent, its color darker and more chromatic. Beyond these general trends, is it possible to predict these changes in appearance for a given type of surface, and for a given humidity level? This is the question studied in this book, by drawing up a first inventory of available knowledge and ongoing research in multiple fields of application: in remote sensing, to correctly identify surfaces and estimate moisture content; in public lighting, to improve visibility on wet roads; in computer graphics, to render wet surfaces in a more realistic way… There is no universal model to describe the changes in spectral, angular and spatial responses of a wetted surface. The mechanisms of light scattering are not affected in the same way according to whether the material is porous, fibrous, powdery, and can be filled by water, or impermeable and can be covered by a water layer. In some applications where the infrared domain is of interest, the strong absorptance of water is also to be considered. This book was initiated by the GDR Appamat, a grouping of research focused on material appearance created in 2019 by the French national center for scientific research (CNRS). In 9 chapters, 26 specialists from various disciplines present different approaches that open perspectives on this field of research. Hopefully, students, engineers, and researchers will be inspired by these ideas to propose future developments.

Preface .....................................................III

CHAPTER 1

Visual Effects of Surface Tension on the Appearance of Wet Surfaces ...... 1

Pascal Barla, Loїc Lachiver and Gaёl Guennebaud

1.1 Different Types of Surfaces................................. 2

1.2 Surface Tension at Various Scales............................ 4

1.3 A Phenomenological Model................................. 5

1.4 Discussion.............................................. 8

References.................................................. 8

CHAPTER 2

Reflectance of Wet Natural Soils in the SolarDomain: Contributions and Limitations of PhysicalModels................................ 11

Alice Dupiau, Stéphane Jacquemoud and XavierBriottet

2.1 Layered Models.......................................... 13

2.2 Particulate Models....................................... 16

2.3 BRF Models............................................ 19

2.4 Conclusion and Perspectives................................ 21

References.................................................. 23

CHAPTER 3

Can the Interpretation of Wet Sand Spectral Responses be Considered a Solved Problem?............................................ 27

Gladimir V. G. Baranoski and Mark Iwanchyshyn

3.1 Case Study: Expected and UnexpectedPredictions ............... 30

3.2 Practical Implications and FuturePerspectives .................. 33

References.................................................. 34

CHAPTER 4

Spectro-Photometric Signatures of Water inPlanetary Regoliths ......... 37

Antoine Pommerol, Marion Massé and Bernard Schmitt

4.1 Experimenting with Analogues.............................. 39

4.2 Reflectance Measurements.................................. 40

4.3 BRDF of Wet JSC Mars-1 and Basalt Samples.................. 40

4.4 Spectral Evolution of Drying Salt-Basalt Mixtures ............... 42

4.5 Reflectance of Intimate Mixtures of WaterIce and Dust ........... 45

4.6 Conclusions and Perspectives............................... 47

References.................................................. 47

CHAPTER 5

Measure of Optical Properties of Paper when wetting using Monte-Carlo Inversion................................................... 51

Laurent Brunel

5.1 Radiative Transfer Properties............................... 52

5.2 Measurement of Radiative Transfer Properties .................. 52

5.3 Experiments ............................................53

5.4 Results................................................ 55

5.5 Interpretation........................................... 58

5.6 Comparison Between Rendering and Photography ............... 58

5.7 Conclusion .............................................60

References.................................................. 60

CHAPTER 6

Wet Road Surfaces, a Challenge for Road Users…and for Measurement ... 63

Enoch Saint-Jacques and Roland Brémond

6.1 The BRDF of Road Surfaces ................................63

6.2 Wet Road Surfaces....................................... 66

6.3 BRDF Measurement of Road Surfaces and Wetness Monitoring ..... 67

6.4 Measurements of the “Wetness” with UGE’s In-Lab

Goniore flectometer .......................................69

6.5 Conclusion............................................. 71

References.................................................. 72

CHAPTER 7

A Virtual Goniophotometer for Modeling the Light Scattered by Rough Surfaces Covered with a Water Layer.............................. 73

Mickaël Ribardière, Benjamin Bringier, ArthurCavalier, Léo Jourdy, Lionel Simonot, Mathieu Hébert and Daniel Meneveaux

7.1 Virtual Goniophotometer.................................. 75

7.2 Results and Discussion.................................... 79

7.3 Conclusion............................................. 83

References.................................................. 84

CHAPTER 8

Determination of the Water Layer Thickness from the Laser Halo ........ 85

Lev Dolin, Fanny Dailliez and Lionel Simonot

8.1 Laser Halo Theory: Formulation of the Problem ................. 86

8.2 Halo Formed by Light Within Non-Scattering Water.............. 89

8.3 Influence of Light Scattering in Water on the Halo Visibility ........ 92

8.4 The Water IOP Determination Algorithms..................... 98

References.................................................. 101

CHAPTER 9

Impact of a Transparent Layer on the Color of a Non-Homogeneous Colored Support.............................................. 103

Fanny Dailliez, Mathieu Hébert, Lionel Simonot, Lionel Chagas, Anne Blayo and Thierry Fournel

9.1 Halo Effect and Darkening Phenomenon....................... 104

9.2 Reflectance Modelling..................................... 106

9.3 Application to Halftone Colors.............................. 113

References.................................................. 115

Contributors ................................................117

Sujets

• Sciences appliquées
• Ingénierie
• Sciences appliquées
• Sciences appliquées
• Ingénierie
• materials
• Sciences et techniques
• Radiometry
• Physics
• Optics
• Lights
• Ondes
• Science
• Physique
• Physical attractiveness

Informations

• Publié par: EDP Sciences
• Date de parution: 02 février 2023
• Nombre de lectures: 1
• EAN13: 9782759829316
• Langue: English
• Poids de l'ouvrage: 12 Mo

Extrait

9 782759 829309

Institut d’Optique Graduate School Advanced Textbook

Directed by Lionel SIMONOT

Radiometry of Wet Surfaces

When Water Matters

Institut d’Optique Graduate School Advanced Textbook

ISBN : 978-2-7598-2930-9

9 782759 829309

Radiometry of Wet Surfaces When Water Matters

Directed by Lionel SIMONOT

As everyone can see every day, many objects or materials change their appearance when they get wet. Most of the time, the object becomes more translucent, its color darker and more chromatic. Beyond these general trends, is it possible to predict these changes in appearance for a given type of surface, and for a given humidity level? This is the question studied in this book, by drawing up a first inventory of available knowledge and ongoing research in multiple fields of application: in remote sensing, to correctly identify surfaces and estimate moisture content; in public lighting, to improve visibility on wet roads; in computer graphics, to render wet surfaces in a more realistic way…

There is no universal model to describe the changes in spectral, angular and spatial responses of a wetted surface. The mechanisms of light scattering are not affected in the same way according to whether the material is porous, fibrous, powdery, and can be filled by water, or impermeable and can be covered by a water layer. In some applications where the infrared domain is of interest, the strong absorptance of water is also to be considered.

This book was initiated by the GDR Appamat, a grouping of research focused on material appearance created in 2019 by the French national center for scientific research (CNRS). In 9 chapters, 26 specialists from various disciplines present different approaches that open perspectives on this field of research. Hopefully, students, engineers,and researchers will be inspired by these ideas to propose future developments.

www.edpsciences.org

Institut d’Optique Graduate School Advanced Textbook

Directed by Lionel SIMONOT

Radiometry of Wet Surfaces

When Water Matters

Institut d’Optique Graduate School Textbook Series: The IOGS Textbook series is a collection of books based on the training provided to the school’s engineering students. Focusing on the main field of modern photonics, these books present in a comprehensive manner the knowledge essential to the professions of engineers and researchers in this discipline. Written in a clear and pedagogical manner, in English or in French, these books are intended to support experts, during their training at the school, but also in their daily professional life.

Institut d’Optique Graduate School Advanced Textbook Series: Based on seminars, conferences or the longstanding experience of the school’s researchers or collaborators, these books aim at presenting recent developments in one of the many fields of this discipline.

Cover Illustration: Beach in Sardinia 2012,G. Baranoski.

Printed in France

EDP Sciences–ISBN(print): 9782759829309–ISBN(ebook): 9782759829316 DOI: 10.1051/9782759829309

All rights relative to translation, adaptation and reproduction by any means whatsoever are reserved, worldwide. In accordance with the terms of paragraphs 2 and 3 of Article 41 of the French Act dated March 11, 1957,“copies or reproductions reserved strictly for private use and not intended for collective use”and, on the other hand, analyses and short quotations for example or illustrative purposes, are allowed. Otherwise,“any representation or reproduction–whether in full or in part–without the consent of the author or of his successors or assigns, is unlawful”(Article 40, paragraph 1). Any representation or reproduction, by any means whatsoever, will therefore be deemed an infringement of copyright punishable under Articles 425 and following of the French Penal Code.

Science Press, EDP Sciences, 2023

Preface

GDR Appamat is a grouping of research focused on material appearance created in 2019 by the French national center for scientific research (CNRS). GDR Appamat covers broad disciplinary fields. In terms of applications, it concerns remote sensing, physics and chemistry of materials, cosmetics and dermatology, analysis and restoration of works of art, classical and 3D printing, lighting, image synthesis, etc. The approaches of the researchers involved in the GDR Appamat are also very diverse: optical measurements, sensory metrology, radiometric or electromagnetic modeling, simulations, and visual rendering. The question we ask and attempt to answer in this book is: how is the appear ance of an object changed when it is wet? In general, as can be observed every day, the object becomes darker and more translucent. However, these are only qualitative observations. To try to investigate the optical effects underlying these changes in appearance, and if possible to model, quantify and predict them, a workshop was organized by GDR Appamat in June 2021. The presentations in this workshop showed that light scattering mechanisms affected by the presence of water depend a lot on the material structure: The optical response is not the same for a moistened porous or powdery material, or for an impermeable diffusing medium covered with a film of water. Moreover, even though appearance is related to human vision, thereby to the visible spectrum of light, the problem can be extended to a wider spectral range, in particular for satellite imaging applications that use the infrared spectral domain and for which the absorption bands of water are important to consider. The crossview of researchers from these various disciplines and approaches seemed particularly stimulating to us and made us want to share its temporary conclusions through this book. The contributors have respected the multidisciplinary spirit of the workshop by privileging a didactic presentation of their work. The detailed developments can be found in the bibliographic references. More than answers, this book opens up ave nues for investigation. It is up to the reader to take advantage of it, either from a

DOI: 10.1051/9782759829309.c901 Science Press, EDP Sciences, 2023

IV

Preface

fundamental research stand point or simply to try to explain effects such as morning dew, a spilt glass of water, wet earth or sand…Material appearance sciences are indeed also a matter of observation and visual poetry.

Detail of a Roman mosaic in Villa Romana del Casale, Sicily, Italy. The colors of the mosaic are faded due to the alteration of the surface over time, but it is enough to wet it (see the right part of the flower pattern) to retrieve dark and saturated colors close to the original ones.

Mathieu Hébert and Lionel Simonot Director and deputy director of GDR Appamat

Contents

Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

CHAPTER 1 Visual Effects of Surface Tension on the Appearance of Wet Surfaces . . . . . . Pascal Barla, Loїc Lachiver and Gaёl Guennebaud 1.1 Different Types of Surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 Surface Tension at Various Scales . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.3 A Phenomenological Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

CHAPTER 2 Reflectance of Wet Natural Soils in the Solar Domain: Contributions and Limitations of Physical Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alice Dupiau, Stéphane Jacquemoud and Xavier Briottet

2.1 Layered Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2 Particulate Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3 BRF Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4 Conclusion and Perspectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

CHAPTER 3 Can the Interpretation of Wet Sand Spectral Responses be Considered a Solved Problem? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Gladimir V. G. Baranoski and Mark Iwanchyshyn

3.1 Case Study: Expected and Unexpected Predictions . . . . . . . . . . . . . . . 3.2 Practical Implications and Future Perspectives . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

III

1

2 4 5 8 8

11

13 16 19 21 23

27

30 33 34

VI

Contents

CHAPTER 4 SpectroPhotometric Signatures of Water in Planetary Regoliths . . . . . . . . . Antoine Pommerol, Marion Masséand Bernard Schmitt

4.1 Experimenting with Analogues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2 Reflectance Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3 BRDF of Wet JSC Mars1 and Basalt Samples . . . . . . . . . . . . . . . . . . 4.4 Spectral Evolution of Drying SaltBasalt Mixtures . . . . . . . . . . . . . . . 4.5 Reflectance of Intimate Mixtures of Water Ice and Dust . . . . . . . . . . . 4.6 Conclusions and Perspectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

CHAPTER 5 Measure of Optical Properties of Paper when Wetting Using MonteCarlo Inversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Laurent Brunel

5.1 Radiative Transfer Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2 Measurement of Radiative Transfer Properties . . . . . . . . . . . . . . . . . . 5.3 Experiments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5 Interpretation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.6 Comparison Between Rendering and Photography . . . . . . . . . . . . . . . 5.7 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

CHAPTER 6 Wet Road Surfaces, a Challenge for Road Users…and for Measurement . . . Enoch SaintJacques and Roland Brémond

6.1 The BRDF of Road Surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2 Wet Road Surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3 BRDF Measurement of Road Surfaces and Wetness Monitoring . . . . . 6.4 Measurements of the“Wetness”with UGE’s InLab Gonioreflectometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

37

39 40 40 42 45 47 47

51

52 52 53 55 58 58 60 60

63

63 66 67

69 71 72

Contents

CHAPTER 7 A Virtual Goniophotometer for Modeling the Light Scattered by Rough Surfaces Covered with a Water Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mickaël Ribardière, Benjamin Bringier, Arthur Cavalier, Léo Jourdy, Lionel Simonot, Mathieu Hébert and Daniel Meneveaux

7.1 Virtual Goniophotometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.2 Results and Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.3 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

CHAPTER 8 Determination of the Water Layer Thickness from the Laser Halo . . . . . . . . Lev Dolin, Fanny Dailliez and Lionel Simonot

8.1 Laser Halo Theory: Formulation of the Problem . . . . . . . . . . . . . . . . . 8.2 Halo Formed by Light Within NonScattering Water . . . . . . . . . . . . . . 8.3 Influence of Light Scattering in Water on the Halo Visibility . . . . . . . . 8.4 The Water IOP Determination Algorithms . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

CHAPTER 9 Impact of a Transparent Layer on the Color of a NonHomogeneous Colored Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fanny Dailliez, Mathieu Hébert, Lionel Simonot, Lionel Chagas, Anne Blayo and Thierry Fournel

9.1 Halo Effect and Darkening Phenomenon . . . . . . . . . . . . . . . . . . . . . . . 9.2 Reflectance Modelling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.3 Application to Halftone Colors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

VII

73

75 79 83 84

85

86 89 92 98 101

103

104 106 113 115

117