Sea Surface Moving Target Detection Using a Modified Keystone Transform on Wideband Radar Data

Round 1

Reviewer 1 Report

This paper proposed a sea surface moving target detection method based on modified Keystone transform (MKT). It mainly involves two key points, MKT and improved energy integration (IEI). However, there are some major issues should be addressed.

1.  In Eq. (6), what does the symbol “m” stand for? Is it an expression error? Please explain or correct accordingly.

2.  The test statistic ${\lambda _{EI}}$ in Eq. (8) obeys ${\chi ^2}$ distribution, then what distribution do the optimized test statistic ${\lambda ^'}$？

3.  As the authors said, “From (12), it can be observed that compared to the shorter detection window, the detection statistic ${\lambda ^'}$ corresponding to the longer detection window is more stable”, however, in your simulation, the target only occupied few range cell, whether this simulation condition can highlight the advantages of the above analysis?

4.  In the section “Adaptive Detection Window”, step 1, the length of the window is determined by the target size. However, in practical applications, the target is often unknown and the target size is uncertain, is this way of determining the window length appropriate?

5.  In the simulation, the velocity of the target is set to 80m/s to emphasize the range cell migration and Doppler ambiguity brought by the motion, but the velocity range of the moving target in the real scene needs to be obeyed. Please consider modifying the simulation conditions.

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

Comments for author File: Comments.pdf

Author Response

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Reviewer 3 Report

This paper addresses the range cell migration problem of moving targets with wideband radar.  It presents an improved detection method for a moving target in a sea clutter environment. 

The proposed method is described first and then validated with simulated radar returns of a moving target with clutter.  Both simulated clutter and real sea clutter are employed for validation.

The paper is technically sound, but has some shortcomings which are described below.

1. The title is confusing.  Suggest: Sea Surface Moving Target Detection Using Modified Keystone Transform on Wideband Radar Data

2. The English is generally acceptable but needs improvement in key places.  I will point out only a few important changes. 

2. In abstract,

a. However, due to the increase of radar range resolution,  --> However, as the radar range resolution increases

a. due to the target’s attitude relative to the radar, the distribution characters of the target--> due to the target's orientation and structure relative to the radar, the distribution characteristics of the target

b.  which decreases the sensitivity  --> which minimizes the sensitivity 

c.  The experiments are conducted by comparing the proposed method with some existing competitors --> Experiments are conducted by comparing the proposed method with other competing methods

3. Under Introduction, defocusing of the target high range resolution profiles --> defocusing of the target high-resolution range profiles

Section 2.1 Assumed --> Assuming

In Eq. (6), I think there should be no m after F.  Also define F here.

Fig. 2, The flowchart is somewhat confusing.  One way arrows are pointing to the blocks on the right of the main blocks.  It looks like something flows into the right blocks but their outputs are not returned back to main block. You may state that the block on the right provides details of the corresponding main block.

Section 4.  the validity of MKT is verified detailly --> verified in detail

How is L determined for the Experiments?

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Thank you for addressing my questions, and I do not have other questions.