Acoustic Scattering Models from Rough Surfaces: A Brief Review and Recent Advances
Round 1
Reviewer 1 Report
The article should be corrected in terms of editing. Line 148 and line 269 are the same drawings, I suspect this is an oversight. Please correct this.
Author Response
Please see the attachment.
Author Response File: 
Author Response.docx
Reviewer 2 Report
The practical goal of the theoretical and experimental study of the mechanisms of scattering of waves of different physical nature (acoustic, radio waves, optical) on various objects is to develop methods for reconstructing the characteristics of objects from the parameters of the scattered field. In this regard, the appearance of a review of modern methods for assessing the scattered field on rough and uneven surfaces is undoubtedly timely. The material presented in the ms is of interest to the readers of Applied sciences. However, I believe that this ms can be accepted for publication with minor additions:
- In the works considered by the Authors, it is worth mentioning a number of rather modern works (not considered in this manuscript) and not included in the review by Ogilvy, J.A. [17]. In these works, the application of the Kirchhoff method, the method of "refined boundary condition", etc. is considered to take into account the characteristics of the acoustic field scattered by the roughness:
–L. Bjørnø, S. Sun. Use of the Kirchhoff approximation in scattering from elastic, rough surfaces // Acoust. Phys. 1995. Vol. 41.Iss.5.
- L. Bjorno. Scattering of plane acoustic waves at elastic particles with rough surfaces // The Journal of the Acoustical Society of America 137, 2439 (2015); https://doi.org/10.1121/1.4920909.
- A.L. Gavrilov, S.Z. Dunin, G.A. Maksimov, Scattering of Scalar Fields by Hard and Soft Rough Surfaces Angular Distribution of Intensity, Acoust. Phys. 1992. Vol. 38.Iss.5.
- V.A. Zverev, M.M. Slavinskii.A Method for Calculating the Acoustic Field near a Rough Surface // Acoust. Phys. 1997. Vol. 43.Iss.1. PP. 56-60. - Scattering on a rough surface is physically similar in many respects to scattering on surface waves. In this regard, perhaps, the authors should pay attention to a number of works devoted to this topic, for example:
Salin M.B., Dosaev A.S., Konkov A.I., Salin B.M. Numerical Simulation of Bragg Scattering of Sound by Surface Roughness for Different Valuesofthe Rayleigh Parameter // Acoust. Phys. 2014. Vol. 60.Iss. 4. PP.442-454. - Remarks on the quality of drawings and design:
a) Lines 149 and 152 are repeated.
b) The designations in Figure 2 must be aligned with the designations in the text by writing.
c) In Figures 3, 4, 8-13, various symbols are poorly read.
d) Mentioning figure 1 on lines 269 and 270 looks like a design error.
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Reviewer 3 Report
There are some basic elements of a review paper, abstracted from some academic journals as following:
Review papers are high scholarly contributions articles written by experts who not only know very well the research and technical developments in the field but also are able to critically examine the state-of-the-art and express informed views and provide guidance/ideas of future developments of the research topic.
A review paper is not simply a summary of literature you have reviewed. Be careful not to leave out your own analysis of the ideas presented in the literature. Synthesize the material from all the works—what are the connections you see, or the connections you are trying to illustrate, among your readings.
The paper should include references to all relevant published work world-wide. Typically, papers contain at least 70 to 150 references, depending on the subject area.
The content of the paper needs to be academically inquisitive, make a critical analysis of the research. Avoid neutral/observational comments that only state what the cited work has reported but go beyond and identify research gaps, limitations and opportunities for further research.
The paper should end with a section in which the state-of-the art is summarized and future trends in research highlighted.
There were already a few comprehensive review articles on the Scattering Properties from Rough Surface and some were listed in the bibliography. This is no new subject. I did not see any meta analysis between new methods (also in limited quantity). No deeper insight or future direction was stated in the conclusion.
Author Response
Response to Reviewer 3 Comments
We gratefully thank the reviewer for giving his constructive remarks and useful suggestions, which have enabled us to improve the paper quality. The revised portion is marked in highlighted text in pink in the revised manuscript. The comments of the reviewer are answered point by point in red as follows.
There are some basic elements of a review paper, abstracted from some academic journals as following:
Review papers are high scholarly contributions articles written by experts who not only know very well the research and technical developments in the field but also are able to critically examine the state-of-the-art and express informed views and provide guidance/ideas of future developments of the research topic.
A review paper is not simply a summary of literature you have reviewed. Be careful not to leave out your own analysis of the ideas presented in the literature. Synthesize the material from all the works—what are the connections you see, or the connections you are trying to illustrate, among your readings.
Thank you these advices on writing review papers. We have added all along the text some remarks giving our point of view. Please read the text in pink of the revised manuscript.
The paper should include references to all relevant published work world-wide. Typically, papers contain at least 70 to 150 references, depending on the subject area.
Even if the paper aims at giving a “brief” review as indicated in its title, we have added numerous references following your suggestion, some of them in other domains than acoustics or for other modelling developments. We have quoted more recent references and some recent applications of the methods (notably published in the last 10 or even 5 years). Numerous new references are also devoted to perspectives and works in progress.
Please look at the highlighted references in pink in the text and also the references section.
We have finally added almost 60 new references and the number of references is now 138.
The content of the paper needs to be academically inquisitive, make a critical analysis of the research. Avoid neutral/observational comments that only state what the cited work has reported
Please note that the text highlighted in light brown in the revised manuscript has been reedited for summarizing some initial portions telling what the cited work has reported. It doesn’t change the content.
We have added all along the text new critical remarks highlighted in pink.
but go beyond and identify research gaps, limitations and opportunities for further research.
The paper should end with a section in which the state-of-the art is summarized and future trends in research highlighted.
We have also incorporated a last section of two pages called ” Summary, discussion and perspectives”.
Now numerous perspectives and challenging applications are now evoked.
There were already a few comprehensive review articles on the Scattering Properties from Rough Surface and some were listed in the bibliography.
We have added some other and more recent reviews. Nevertheless, several reviews are more devoted to electromagnetism or to scalar waves in general or to particular applications as scattering from ocean surfaces. That’s why for instance for probably most researchers in Non Destructive Evaluation (NDE) Ogilvy’s review is still seen as the reference since it is more applied to this field. The Recent developments and articles in the last 10 years are likely not be discussed in other reviews. Moreover we are convinced there is the need for a review specialized in acoustics and also giving several particular applications of the methods in acoustics and notably ultrasonic ones (it is also the scope of the special issue of this submission). There are obviously the historical applications (ocean, NDE) but new applications (additive manufacturing, medicine…) will require more modelling sophistications.
This is no new subject. I did not see any meta analysis between new methods (also in limited quantity). No deeper insight or future direction was stated in the conclusion.
In the text or in the conclusion, we have described or quoted other methods, new recent developments, other applications of the existing methods, discussed possible extensions or improvements telling if it is worth working of such perspectives. We cannot report here all of these new points (some are given hereafter) and please ask you to read in the revised manuscript the highlighted in pink.
You will find also highlighted in cyan some methods inserted for taking in to account the remarks of another of the four reviewers.
To be more complete in the review, we have talked about two old approximations with notably application to scattering from ocean: the phase perturbation method (end of section 3.1) which is another perturbation method and the two-scale roughness theories (beginning of section 4) assuming that scattering can be considered as the combination of scattering produced by large facets and well approximated by KA and that due to small roughness and approximated by Perturbation theory.
We have provided extensions or validations of existing methods for fluid or elastic medium behind the interface.
We have widely discussed about the validity of Kirchhoff approximation (KA) at the end of Section 3.2.2. The question of Kirchhoff approximation validity has been studied in a too simplified manner in previous reviews of the literature. New numerical or experimental validations have been performed since these reviews. The KA validity is of great importance for numerous applications as Non Destructive Evaluation which often employs near specular observation inspection. Indeed we have connected and merged recent studies of the KA validity and conclude that for many applications two criteria can be used for KA validity. It provides more precise and less restrictive criteria than in previous reviews. It demonstrates the possibility to accurately employ Kirchhoff in NDE configurations for simulating roughness effects for relatively small correlation lengths compared to the wavelength.
In the conclusion section, due to the inaccuracy of Kirchhoff and even other methods near some particular angles (as the critical angles) we notably discussed the difficulty in improving analytical methods for taking into account both roughness and head waves generated at critical angles.
We highlighted that researches try now to reduce calculation time of numerical methods and that these models could be very useful to deal with new perspectives as additive manufacturing, complex materials or substrates, medicine.
We thank you again very much for all your honest and useful suggestions. We hope that we have well responded to them and that corrections will meet with approval.
Author Response File: Author Response.docx
Reviewer 4 Report
Comprehensive review of the state of the art in a very specialised field, as the title suggests - I think it will be useful when published and do recommend publishing the article.
There are some technical problems with the images from Figure 1 (d) and (e) appearing 3 times in various places in the PDF manuscript, which I am sure will be corrected in the final version.
Author Response
Please see the attachment.
Author Response File: Author Response.docx
