Near-to-Far Field RCS Calculation Using Correction Optimization Technique

Round 1

Reviewer 1 Report

The authors should be congratulated for a very thorough paper using experimental data to verify their new algorithm to estimate the FF RCS from sampled NF data.  The one-dimensional optimization of the step size for the gradient search is especially good.  I wonder whether the accuracy of the estimates of FF RCS might be improved by mitigating ill-conditioning of the Hankel matrix.  The authors use an SVD of the Hankel matrix, but perhaps some type of regularization (e.g., Tychonov or shrinkage) would be even more accurate.  This would be for future research.

There are many grammatical errors and incorrect words in this paper.  In the abstract alone there are three errors: (1) the first sentence does not make sense; (2) on line 7 the word should be "convolved" rather than convoluted; and (3) on line 8 the word should be "geometric" rather than geometry.  Please get help from a fluent English writer to correct such grammatical errors.

Author Response

The co-authors and I sincerely appreciate all the valuable comments provided by the reviewer. We are grateful for the time and effort invested in reviewing the manuscript. Thank you for your valuable feedback again, and we will strive to improve the quality of our work based on your suggestions. The point-by-point responses can be found in the attached Word document.

Author Response File: Author Response.pdf

Reviewer 2 Report

See Pdf File

Comments for author File: Comments.pdf

There are few typos in the manuscript.

Author Response

The co-authors and I sincerely appreciate all the valuable comments provided by the reviewer. We are grateful for the time and effort invested in reviewing the manuscript. In the revised version, we will thoroughly address each comment, ensuring that the changes made are highlighted in yellow for better visibility. Thank you for your valuable feedback again, and we will strive to improve the quality of our work based on your suggestions. The point-by-point responses can be found in the attached Word document.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The second version of the paper is better than previous one, however there are still many rooms to improve the overall quality of the proposed manuscript. The authors should consider carefully the comments provided by the reviewers because we are trying our best to improve the quality of the paper and therefore it can have a nice impact on most of readers. Authors should not consider these comments as against them or their study. I notice that most of my previous comments have not been well addressed in the paper. In fact, in many cases, the authors replied directly to my comment without modifying the manuscript. The authors are highly encouraged to modify the manuscript instead of just reply in private way to the reviewers’ comments. Reviewing properly a paper takes time, but as a reviewer is my duty to try to give the authors another point of view and help them to improve the quality of their manuscript. In fact, I am trying to be fair and apply the same rules that I use to correct my Phds and postdocs’ papers.

Further comments are provided as follows:

The authors are encouraged to cite the references for all their equations or specify if it is a definition or elsewhere they should provide the proof. In this case, the readers can easily go through the proposed equations.

The issue with equation 7 is still unsolved, as we can't use the same variable r' twice in the same integral. otherwise, we will have d^6r' instead of d^3r' d^3r'. So please rewrite that equation.

Line 141, L was heuristically chosen, what is the impact of that choice?

The authors replied to this previous comment by saying "The parameter "L" in our manuscript is determined based on the length of the scattering field sequence. When setting up the Hankel function, the parameter "N" is heuristically defined, typically as [N/2]. Thank you for raising this concern. " First of All, the authors are encouraged to add their answer to the original paper, similar advice for all the provided answers. Because that will help readers to go more smoothly through the submitted paper. Second, the authors should in this case consider the impact of N!

Concerning the asterisk (*) the authors are highly encouraged to used different symbol to design the convolution product and another symbol for the complex conjugate.

I agree with the authors that equation (15) is well known etc, but even though the authors should provide their reference for all equations.

 

Concerning my previous comment on figure 2, "Figure 2: it is strange to have a RMSE completely independent from the SNR and it is constant? How can we also justify the constant difference between the three straight-lines.  The authors should revise their simulations or explain the result! " The answer of the authors is not satisfactory as saying "The results presented in Figure 2 are obtained from real simulations without fake components. " I think that the authors misunderstood this comment, as I am not accusing them by cheating or else. But from physical point of view the result is still strange, so the authors should check their setup or they should explain the reasons to get such behavior.

If any figure has been published before than the authors should clearly mention that.

Concerning my previous comment "As most of the given equations, in the manuscript, can be found in the literature, the authors should well highlight their contributions. " I advise highly the authors to highlight better their contribution, their reply it is enough.

In a previous comment "Figure 12, By comparing the FF and error curves, we can conclude that they are very similar except of a constant shift, which in db can be considered as a constant multiplication factor. Where this factor coming from? " Where the authors replied as "The results presented in Figure 12 are based on real simulation data and do not contain any fabricated information. " Again, I am interested in the physical fact (and not assuming fake results), so the authors should explain the similitude among the presented curves as by my previous comment.

 

So please reconsider all previous comments and try to clarify the raised points for the common readers and not just for the reviewers or the editors as other readers may ask the same questions.

Author Response

All the replies in the word file. 

Author Response File: Author Response.pdf

Round 3

Reviewer 2 Report

The 3rd version of the manuscript is better than the previous ones.