Anti-Jamming Imaging Method for Carrier-Free Ultra-Wideband Airborne SAR Based on Variational Modal Decomposition

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This paper investigates an anti-interference imaging method for carrier free ultra-wideband airborne synthetic aperture radar (SAR) based on variational mode decomposition (VMD). The effectiveness and efficiency of the VMD algorithm in resisting noise amplitude modulation (NAM) and noise frequency modulation (NFM) interference are verified. This paper demonstrates a high level of theoretical analysis and experimental verification, and the proposed method is innovative and suitable for practical application scenarios. The authors have to implement the following suggestions before the manuscript becomes acceptable for publication.

1) The literature review is not detailed enough. Although this article mentions some relevant literature, the review of existing anti-interference methods is not comprehensive enough. Suggest expanding the literature review section to discuss in detail the advantages and disadvantages of various existing anti-interference methods to provide a more solid theoretical basis for the proposed method in this paper.

2) The theoretical derivation part is not detailed enough, and the theoretical derivation part of the variational mode decomposition algorithm is relatively brief, lacking detailed explanations for some key steps. Please add a detailed description of the key steps of the VMD algorithm, especially a discussion on how to select parameters and the convergence of the algorithm.

3) The diversity of experimental data is insufficient. The experiment mainly focuses on a specific interference scenario, lacking testing for other forms of interference. Please increase testing of algorithm performance under various forms of interference to further validate the universality and robustness of the method.

4) The analysis of algorithm complexity is missing, and the article did not provide a detailed analysis of the computational complexity of the VMD algorithm. Please increase the computational complexity analysis of VMD algorithm and discuss its feasibility and efficiency in practical applications.

5) Please carefully check the format of the formulas and charts in the paper. For example, the Eq. (2) and Fig. 1 are not clear.

Comments on the Quality of English Language

Language needs to be improved to make it easier to understand.

Author Response

See the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The paper is nicely organized, with a summary, introduction, methods, findings, and conclusions. The transition, between each section, is smooth and logical. To improve readability and effectiveness, it might be beneficial to ensure that each section stays focused on points without delving into specifics. Additionally expanding on research plans could be valuable, for discussion.

Comments on the Quality of English Language

Minor editing of English language required

Author Response

Thank you very much for the reviewer's affirmation and encouragement. I am deeply grateful for your praise. This article has been carefully prepared and created with great effort, and I am glad that it has received your recognition. If you have any specific suggestions or ideas, I would be more than happy to listen and consider them. In my future work, I will continue to work hard to bring readers more in-depth and valuable content. Thank you again for your support and affirmation. This is of great significance to me and also the greatest motivation on my journey ahead.

Reviewer 3 Report

Comments and Suggestions for Authors

This article study the effects of two kinds of interference (NAM and NFM ) for airborne SAR. Using the VMD algorithm to anti-jamming, and the anti-jamming performance is compared with the EMD algorithm. From the research results of the article, the VMD algorithm is effective. There are some problems to solve before it is considered for publication. The problems are as followed:(1)This article focuses on the anti-jamming of using the VMD algorithm, but a considerable amount of length was spent on the BP imaging algorithm, which resulted in some redundancy in this section. I think it's appropriate to delete some parts of the BP algorithm.(2)The author introduce the process of VMD algorithm starting from line 380. The first step is to say that the value of K is usually taken as 3-7, what is the author's value for K, and how is the value of parameter K confirmed.(3)What is detailed content of convergence condition for stopping after meeting the convergence condition in the fourth part in line 390 and in Eq.(17).(4)The text content in Figure 13 is too large, making the image appear small and unattractive. It is recommended to make modifications.(5)In Figure 13, the annotations for both images are NAM, but according to the introduction below, one of them should be NFM. This should be the author's negligence.

Author Response

See the attachment.

Author Response File: Author Response.pdf