Airborne Radar Space–Time Adaptive Processing Algorithm Based on Dictionary and Clutter Power Spectrum Correction
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsIn this paper, the authors provided a STAP algorithm for airborne radar based on dictionary and clutter power spectrum joint correction (DCPSJC-STAP) which can tackle the off-grid issue and improve the moving target detection performance in actual complex clutter environments. The proposed algorithm sounds interesting. However, there are several problems need to be solved. The detailed comments are given as follows.
1. Please explain how to determine maximum of iterations “t” in line 306. Why the algorithm can converge when the iterations is “t”?
2. Please give the definition of SCNR loss. According to the Figure 5, the CRNR-STAP has the best performance, why do the authors say DCPSJC-STAP has the best performance. Please provide sufficient evidence.
3. In Figure 6, the performance of DCPSJC-STAP seems similar to SBL-STAP, but why there is no the output power of SBL-STAP after range gate 155.
4. The authors should provide the experiment about SCNR loss versus the number of training samples.
5. As the authors point out, ANM has good performance to cope with the off-grid effect. I urge the author add the performance of ANM to the experiments, such as Figure 5, Figure 6, etc.
6. There exist many phrases which may represent the same connotation, such as range cell snapshots, snapshots, samplings, sample, training samples, etc. For ease of understanding, it is necessary to make them consistent.
7. It is necessary to check the accuracy of all phrases, such as range cell to be detected in line 138. Although the expression has no grammar error, it does not accord with the common usage, i.e., range cell under test.
8. A lot of symbols, such as E[], []H, IMN, are not explained in the paper. It is preferable to add a paragraph to define these symbols clearly at the end of Introduction.
Comments on the Quality of English LanguageThe quality of English language should be improved. The organization of article should also be improved, especially in Introduction.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for Authors[1] Grammar and writing style need to be improved, professional editing service is recommended.
[2] Eqns.(3), (4), (5): Suggest to cite some references about why and how they take these forms.
[3] Line 159: Please clarify “l distance unit”.
[4] Line 166: Please explicitly define “clutter power spectrum” in mathematical expression.
[5] Line 180: Please elaborate whether “clutter ridge” is a common feature of clutter.
[6] Line 197: Please define “clutter suppression performance” mathematically.
Please elaborate how the estimation of clutter power spectrum is used to suppress the clutter.
[7] Eqn.(16): Please elaborate the difference between “𝑓𝑑,𝑛” and “𝑓𝑑,𝑛(𝜃𝑒,𝑓𝑠,𝑛)”.
[8] Eqn.(17): Please elaborate how “𝛾𝑖” is related to those elements in eqn.(14).
[9] Line 207: Please elaborate how the yaw angle θe’ is embedded in Φ1(m,n,w).
[10] Line 211: Please elaborate how Φ2 (f d,n’, fs,n) is formulated. This step seems crucial.
[11] Line 327: Please explain “noise ratio”.
[12] Figure 5: Please elaborate how the “SCNR loss” is defined and how it is related to the performance of clutter suppression.
[13] The caption of each figure should be improved to contain succinct information for better readability.
Comments on the Quality of English Language
Grammar and writing style need to be improved, professional editing service is recommended.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsThe authors have responded to all my comments and have attempted to address many of the issues raised in my first review. However, the authors’ responses are still inadequate and engender other related issues that need to be addressed.
1. The authors say “Based on the characteristics of the problem and previous experience in dealing with similar problems, an initial number of iterations is set”. I think the authors do not deal with my concerns. It is preferable to supplement relevant references to confirm your setting.
2. Lots of references commonly define SCNRloss as “the ratio of the output SCNR to the SNR achieved by a matched filter in a clutter-free environment”, and this is different from the definition by the authors. Please provide the relevant references.
3. According to my understanding, the STAP has the best performance when the SCNRloss is close to 0. In this case, the CRNR-STAP should has the best performance. Therefore, I cannot understand “the CRNR-STAP method has a shallow dent and a wide notch, so the clutter suppression ability is poor”. Moreover, it is preferable to give the optimal STAP as a benchmark.
4. The authors should state that which normalized Doppler frequency of the SCNRloss in figure 6 belong to.
5. Multiple references commonly define the clutter power spectrum as “1/(sHR-1s)”, and this is different from the definition by the authors. Please give the relevant reference of the definition about “clutter power spectrum” in line 338.
6. The authors say “R is the signal covariance matrix” in line 339 in the revised version, but I cannot find the definition of “signal covariance matrix”.
Comments on the Quality of English LanguageI have no comments.
Author Response
Please see the attachment
Author Response File: Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsPrevious comments have been addressed.
Author Response
Previous comments have been addressed.
