A New Model for Human Running Micro-Doppler FMCW Radar Features

Round 1

Reviewer 1 Report

The topic of the paper is very interesting and findings in this area could be of great importance in practice. It is commendable that the authors performed a real-time experimental verification.

My concerns are, as follows:

-        After reading the paper, I cannot recognize its scientific contribution. Aldo authors say in the Introduction that:

“A more realistic and simpler human model is proposed, which can achieve a high degree of simulation of the real running human body.”

it is hard to get to this conclusion after reading the paper. All I can see is that the authors are reducing the parameters values used in the Thalmann model (62 degrees of freedom and 32 joints to 12 rigid bodies and 16 reference points). If this is true, the scientific contribution is, at best, incremental. If not, provide solid evidence to support your claim from the sentence quoted above.

-        The paper is not well organized and therefore difficult to read. One separate section should be dedicated to presenting the proposed model: to define it in detail, provide the necessary theoretical background, and explain its similarities and differences from the existing models. Section 3 takes more than a half space in the paper. It should be replaced with two new sections: experimental results and comparative analysis. The comparative analysis must include a comparison with state-of-the-art models (in the last couple of years a number of very good solutions were proposed). Here, the authors are providing a comparison only with classical models (Doppler and Thalmann models from 20-30 years ago). Conclusions contain only one paragraph. It should be expanded so it can point out properly all benefits and drawbacks of the model. Additionally, it should include comments about the practical importance of the proposed model, covering actual potential practical applications.

-        References should be updated. More than half of the references are older than 5 years, and more than one-third are older than 10 years. Additionally, a third of the references are from conferences. As stated in the previous request, there are plenty of new solutions that authors can reference.

-        Please explain why did you, among all other time-frequency transforms, used the Hilbert transform? Wigner-Ville transform as well as Spectrogram i.e. provide a very good time and frequency resolution.

The paper needs serious proofreading since there are a lot of technical errors and shortcomings:

-        In the Abstract, lines 14 – 19 are referring to one sentence. This should be rephrased and divided into at least two sentences.

-        Lines 48 and 60 contain the note: [Error! Reference source not found.] This should be fixed.

-        Line 74 ends with : which implies that some kind of listing is expected, but instead of it we have a new sentence. So, either listing should be made, either: should be replaced with a dot.

-        Equation (2) uses σ, but it is not defined.

-        In line 97 R is defined but not used. Instead, r(t) is used. Are they the same?

-        In line 99 authors say: The echo signal is mixed…What does that mean? Mixed in what manner?

-        Intermediate Frequency (IF) is defined in line 100 but used earlier in line 99.

-        In line 112, the authors are using concepts like left/right big arms, left/right small arms, left/right big legs, left/right small legs. Please explain.

-        The abbreviation RCS is used in 124 but never defined.

-        A sentence from 126-127 should be either split in two or rephrased.

-        Parameter k is used in equation (5), but it is not defined. Parameter K is defined. Are k and K the same?

-        Lines 129 – 133 are referring to one sentence. This should be rephrased and divided into at least two sentences.

-        Ri is defined in line 136 but used earlier in line 134.

-        In line 144 should be “is the most common device” instead of “is the more common device”.

-        Fig. 5 and Fig. 6 are deep in the margins of the document.

-        Table 2 should be reorganized, so it presents data more clearly.

-        A sentence in line 224 should start with a capital letter (The peak is the highest…)

 

Having in mind all the above I suggest a major revision of the paper and strongly recommend to the authors to carefully address all pointed concerns.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

 

The paper is indeed interesting, but it needs further scientific editing.

1. Some important numerical findings should be provided in the Abstract.

2. The logical flow in the Introduction is not well developed and it is not clear for the readers what are the key knowledge gaps and objectives of the researchers to fill them.

3. In the introduction, the innovation of the manuscript is well discussed, but it is better to add the following references to enrich the work.

10.1117/1.JRS.9.097695

10.14358/PERS.83.1.41

4. Please be clear about the purpose of the article and the research innovation aspects at the end of the introduction.

5. The quality of Fig. 1 is very low.

6. The information of Table 1 can be replaced in the text.

7. Fig. 2 can be added as a subset of Fig. 1.

8. The tables should be analyzed more qualitatively in the Results and Discussion section.

9. The conclusion is justified, but it could be extended, highlighting the advantages of the proposed method and specifying exactly what is new?

 

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The improvement in paper quality is notable, especially in comparison to its first version. The authors have, mainly, resolved my previous concerns. Before paper acceptance, a couple of things should be addressed:

-        The paper needs proofreading since there are a lot of technical errors and shortcomings. Additionally, a serious English spell check must be done. I strongly recommend that a native (or at least professional) English speaker checks the paper. Examples:

-    Lines 19-22: …human body can be reach above 90%... (can reach); …human model can be reach to 90.6% (can reach up to),

-    Line 32: there is a dot (.) in the middle of a sentence,

-        Lines 46-47: incomplete sentence

-        Lines 47-49: incomplete sentence

-        Line 52: aftermentioned?

-        Line 52: manikin?

-        Lines 55-56: incomplete sentence

-        Line 59: incomplete sentence

-        Lines 198-200: incomplete sentence

-        Lines 219-220: incomplete sentence

-        Lines 221-222: incomplete sentence

-        Lines 227-228: Error! Reference source not found

-        Line 358: Author Contributions must be stated in the new line

 

-        In line 233 authors say: …sampling frequency is 2.5e6. Does this mean 2.5MHz?

-        Figures and tables should be at the beginning or at the bottom of the page (not in the middle of it).

 

Having in mind all the above I suggest a minor revision of the paper.

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

The authors have addressed all my concerns.

Author Response

Thank you for your review, this is our latest revised paper,

Author Response File: Author Response.docx

Reviewer 3 Report

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.pdf

Round 3

Reviewer 3 Report

This paper presents a new model with digging Micro-Doppler FMCW Radar Features for Human Body Detection. The topic is interesting. However, it still has some comments proposed last time need to be addressed. 

 

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.pdf