A New Waveform Design Method for Multi-Target Inverse Synthetic Aperture Radar Imaging Based on Orthogonal Frequency Division Multiplexing Chirp

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

1．        There are lots of errors in the formula format of the full paper, such as  in line107,  in line 223, suggest carefully check and modify the formula format of the full text.

2．        Figure 1 needs to give a more detailed description to explain that multi-target imaging cannot be uniformly compensated for motion.

3．        The Figure 2 has some annotation errors,  is not in Figure 2. At the same time, Figure 2 does not fully explain the two multi-target transmission resource allocation methods.

4．         and  should be reflected in formula 5 and explained.

5．        What is the relationship between h and p in formula 6 and formula 2? Does it mean the same meaning? If so, the full text should be consistent.

6．        Equation 7 requires a more detailed derivation.

7．        The m-th in line 150 and 166 has been defined twice with different meaning.

8．        The relationship between  and  in Equation 24 and 25 needs more detail derivation.

9．        The Figure 10, 15, 16, 17 needs to give a detailed description.

10．     The method presented in this paper has good performance under low SNR in line 319, and the corresponding comparison should be given.

11．     In this paper, the problem of multi-target imaging is solved. The simulation results given in the simulation verification part should be at least three targets.

12．     The experiments in this paper verify that the targets are in the azimuth symmetrical position. If the targets are not in the symmetrical position, this algorithm is applicable? The experimental results must be given under this conditions.

13．     The 2D imaging results needs to given in section 5.2.

14．     The article does not discuss the current research situation enough, and the references can not reflect the research direction in recent years.

Author Response

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Author Response File: Author Response.doc

Reviewer 2 Report

Comments and Suggestions for Authors

A New Waveform Design Method for Multi-Target ISAR Imaging Based on OFDM Chirp

1.      In the equations, integers, and constants used must be elaborate in detail to understand the mathematic concepts thoroughly.

2.     If the chirp rate is varying what will be the overall effect on the echo calculation?

3.      Figure 1 must be high definition and have a clear resolution to analyze the data representation. Please include any additional comments on the figures for more technical clarification.

4.     Prepare a comparative table of all the state of art techniques for the same application to prove the novelty of the work.

5.     Illustrate what are the manuscript’s strengths and weaknesses;

6.     In equation 32 and 33, what “O” represents?

7.     Reference 19, article is seems like a base article for this work. What is the main difference in both of these papers?

8.  Few references are too old. Please add a few recent references.

9.  Overall paper is well-written and seems technically strong after correcting these corrections/suggestions.

Comments on the Quality of English Language

-

Author Response

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Author Response File: Author Response.doc

Reviewer 3 Report

Comments and Suggestions for Authors

 

1.      In the background, some current waveform design methods besides the LFM signal is suggested to be covered as the development of multi-target imaging and detection algorithms:

[R1] E. Raei, M. Alaee-Kerahroodi, P. Babu, et al. Generalized Waveform Design for Sidelobe Reduction in MIMO Radar Systems [J]. Signal Processing, 2023, Vol.206: 108914.

[R2] C. Chu, Y. Chen, Y. Luo, et al. Wideband MIMO Radar Waveform Design under Multiple Criteria [J]. IEEE Geoscience and Remote Sensing Letters, 2023, Vol.20: 1.

[R3] J. Zhu, Y. Song, N. Jiang, et al. Enhanced Doppler Resolution and Sidelobe Suppression Performance for Golay Complementary Waveforms. Remote Sensing, 2023, 15(9): 2452.

2.      The grammar should be double checked and improved.

3.      Some parameters are confused, say the parameter h is simultaneously used for the beam and target index.

4.      In Fig. 6(b), why the amplitude of two targets are not the same?

5.      It seems the Section 4.3 misses some of the paragraphs, since the Time Complexity part is marked as Part A. Please check.

6.      It is also necessary to point out the PRF in the Table 3.

 

 

Comments on the Quality of English Language

The grammar should be double checked and improved.

Author Response

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Reviewer 4 Report

Comments and Suggestions for Authors

The paper proposes original solution how to follow a few target by the same radar with acceptable reliability. They propose to generate signals with several alternately switching directions of radiation and illustrate the feasibility of this approach both numerically and experimentally.

I recommend the manuscript for publication.

Author Response

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Reviewer 5 Report

Comments and Suggestions for Authors

The work is certainly of scientific interest in its field of research. Particularly valuable is the presented method of generating waveforms by 2D orthogonal radar signal diversity to obtain high-quality images. Efficiency has been proven by modeling and experimentation. In the analysis of the work, it would be necessary to consider the problem more broadly in terms of solving it at the global level, and, accordingly, fix this with references in the list of references.

Author Response

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Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The author's answers to the first round of review questions are acceptable

Reviewer 3 Report

Comments and Suggestions for Authors

I have no further comments.