The LPR Instantaneous Centroid Frequency Attribute Based on the 1D Higher-Order Differential Energy Operator
, Zhengchun Song 1, Bonan Li 3, Xuan Feng 1,2,*, Jiangang Zhou 4, Yipeng Yu 5 and Xin Hu 1,5Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsI think that more details about GPR are necessary. It may be a reference to the description or technical characteristics. The only central frequencies are insufficient.
I'd propose that the authors try a grayscale color scheme instead of green-yellow-red, as used in Figures 10 (a) and 5 (a). In the current images, it is complicated for me to see useful information. In contrast, Figure 4 (b) looks very good.
It looks like the section Acknowledgments is not finished.
Author Response
Please see the response in the attached pdf.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe authors present an 1D higher-order differential energy operator that is used to process the GPR/LPR data. The method was introduced clearly enough and supported by both simulated and real measured data. Compred to the typical instantaneous attributes, such as instantanious frequecny, the proposed method privide a better resolution and sensitivity. The manuscript's design is logical. Mostly, this work is supported by the real measured GPR data from Lunar.
Howerer, the language seems to be influenced by the authors' native expression, and should be improved.
Comments on the Quality of English Language
The expression should be improved. From my view, the language in the manuscript seems to, more or less, directly translated from the native expression.
Author Response
Please see the response in the attached pdf.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThe LPR instantaneous centroid frequency attribute was proposed. The article is short and some results should be further discussed. The following issues must be addressed:
1. Abstract: Abbreviations should be given full names. In addition, the background description is too much, it is recommended to cut.
2. The introduction seems to be light and not rich enough. Some key papers about the GPR detection and FDTD simulation in other field should be discussed:
1) Automatic pixel-level detection of vertical cracks in asphalt pavement based on GPR investigation and improved mask R-CNN, https://doi.org/10.1016/j.autcon.2022.104689
2) Energy Level Quantization in the 1D Quantum Well in Case of Instantaneous Stationary State with the Non-Relativistic Wall and Particle Motion
3. Figure 3: the parameters for FDTD model and GPR detection are important, for example, what is the relative dielectric constant of each layer of material?
4. Equation (X) should be mentioned in the main text.
5. The clarity of Figures should be improved, and vector graphics are recommended.
6. Moderate editing of English language required.
7. The discussion part seems too short.
8. Limitations of the study should be appropriately mentioned in the conclusion.
Comments on the Quality of English Language
Moderate editing of English language required
Author Response
Please see the response in the attached pdf.
Author Response File: Author Response.pdf
Reviewer 4 Report
Comments and Suggestions for Authors1. The authors must develop a much deeper discussion comparing the results of the Classical, TKEO, and 1D-HODEO results of the trace analysis. The figure is a useful visual, but still lacks the necessary explicit review of the differences.
2. The authors must include more citations to the geology of the lunar subsurface. Also, they need to add a literature review (even just a few paragraphs) summarizing the geological data produced by others to support the model, and ultimate interpretations. MUST add what software was used to generate the simulated model and data.
3. Authors must improve figure captions, specifically Figure 6. There is a lot going on in the figures and I am finding I must jump back to the text for basic context.
4. The results are confusing. Authors need to improve clarity. Authors should also justify why they believe the 500 MHz antenna is providing return signals as late as 500+ns.
5. The authors should add a discussion on how the data and their interpretations improve our understanding of the lunar subsurface.
6. Add a more explicit discussion of how the proposed 1D-HODEO method will improve workflow.
7. Suggest the authors add a detailed table of the data collection parameters of the radar.
8. While the data derived from the 1D-HODEO method might "look" better, did it ultimately provide the authors with more accurate interpretations?
Comments on the Quality of English Language
Some redundancies, some confusing sections. Minor improvements to English.
Author Response
Please see the response in the attached pdf.
Author Response File: Author Response.pdf
Round 2
Reviewer 3 Report
Comments and Suggestions for AuthorsMy comments on the initial version of the manuscript have been sufficiently addressed by the authors in this revised version. I have no further comments on the technical aspects. The manuscript may be considered for publication after a proofreading.
Author Response
We really thank you for the professional comments in the previous review, which improve the quality of our manuscript greatly.
Other revisions can be checked, see the colored-text in the revised version.
Reviewer 4 Report
Comments and Suggestions for AuthorsI appreciate the authors improvements to the paper and the seriousness in which they addressed the comments. However, there are still a few points that were not addressed in full. Clarifying these is critical for publication.
1. While the authors added 3 referenced, they need to enhance this even more, especially as it relates to our understanding of lunar geology. They should also improve the summary of the current state of knowledge of lunar geology in the area under investigation.
2. Clarify exactly what the 1D-HODEO provided that the other methods didn't. The authors indicate the simultaneous extraction of multiple data points but this quantitative improvement over other methods needs to be shared.
3. The authors may want to consider adding a paragraph at the end that references other applications of GPR that could benefit from their method. This would improve the novelty, significance, and interest to the readers. Applications may include archaeology, environmental sciences, forensic investigations, engineering, etc.
Comments on the Quality of English LanguageOverall, English is presented well. Can use minor editing.
Author Response
Thanks for the comments, and please check the attached pdf.
Author Response File: Author Response.pdf
