Ground Moving Target Tracking and Refocusing Using Shadow in Video-SAR
Round 1
Reviewer 1 Report
See attached file
Comments for author File: 
Comments.pdf
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 2 Report
REVIEW
Article titled “Ground Moving Target Tracking And Refocusing
Using Shadow In Video-SAR”
Remote Sensing no. 923479
List of authors
Xiaqing Yang, Jun Shi, Yuanyuan Zhou, Chen Wang, Hao Hu, Xiaoling Zhang, and Shunjun Wei
- In this paper the Authors proposed a novel framework to refocus ground moving targets by using shadows in video-SAR. With this framework, it is possible to perform detecting, tracking, imaging for multiple moving targets integratedly, which significantly improve the ability of moving targets surveillance for SAR system. The Authors said, that the shadow of ground moving targets is affected by target’s size, radar pitch angle, carrier frequency, synthetic aperture time and etc.
Also, by numerical experiments, the Authors find that a deep network, such as SiamFc, can easily track shadows and precisely estimate the trajectories that meet the accuracy requirement of the trajectories for m-BP.
- The Authors in Introduction made extensive literature review dealing with the most important aspects about SAR image resolution and ground moving target imaging in the aspect of reconnaissance and surveillance tasks. I am forced to draw attention to a very important substantive problem, because in my opinion, in the Introduction, the Authors should also revision of world bibliography concerning the most important aspects for synthetic aperture radar (SAR), Differential SAR Interferometry technology (DInSAR), Along Track Interferometry (ATI), image evaluation, acquisition mechanism of large aperture antennas and frequency bands vs. SAR configurations.
- On the other hand, it is well known that the process of phase unwrapping in SAR technology constrained minimization problem for many well-known algorithms, which are used. Also, a very important problem is acquisition mechanism of large aperture antennas and adaptive forming the beam pattern of antenna.
For this reason, considering possibilities of SAR technologies, the Introduction of this article should be modified, and some articles for example, “On the Capabilities of the Italian Airborne FMCW AXIS InSAR System” or “Deceptive targets generation simulation against multichannel SAR” should be added to the References.
- In Section 2 (Signal Model…..) the Authors model geometry of SAR for observing a ground moving target (Fig. No 1) and briefly review the features of moving targets in SAR image based on BP algorithm. It seems to be correct.
- The Authors employ deep-learning-based tracking network SiamFc to track and locate the shadows of the ground moving target to reconstruct its trajectory.
Why the experiment did not consider other types of networks? Perhaps other types of networks could have a completely different effect on the reconstruction of the trajectory. The above issue should be clarified and explained. An experiment should also be performed. I know, that the validation effect was compared with MOSSE and KCF (Section 5.2), but it should be explain more precisely.
- In Section 4 (Methodology), the flow chart of the m-BP proposed in this paper is shown in Fig. 6, where m denotes the number of moving targets in the scene - as the Authors said.
What is the impact of the number of moving targets in the scene tracked on the quality of this shadow tracking process?
This is not explained anywhere in the article.
- There is also no comment from the Authors on what the computational burden of the proposed method is and if their solution is used in equipment working in real conditions.
The Authors addressed a problem which is relevant and appealing for this Journal. However, I cannot recommend the current manuscript for publication unless the current version is corrected. After providing the amendments to the article, the work ought to be reviewed once again.
Comments for author File: Comments.pdf
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Accepted.
Reviewer 2 Report
REVIEW_2
Article titled “Ground Moving Target Tracking And Refocusing
Using Shadow In Video-SAR”
Remote Sensing no. 923479
List of authors
Xiaqing Yang, Jun Shi, Yuanyuan Zhou, Chen Wang, Hao Hu, Xiaoling Zhang, and Shunjun Wei
Remote Sensing titled “Ground Moving Target Tracking And Refocusing Using Shadow In Video-SAR” has been carefully modified and well revised. The present version of the article includes all remarks found in the reviews.
In this way, present version of this article may be finally accepted for publication in MDPI Remote Sensing.
