Weak Signal Processing Method for Moving Target of GNSS-S Radar Based on Amplitude and Phase Self-Correction
, Fuzhan Yue 1,2,*, Zhenghuan Xia 1,2, Xin Liu 1,2, Chuang Zhang 1,2, Zongqiang Liu 1,2, Shichao Jin 1,2, Yao Zhang 1,2, Zhilong Zhao 1,2, Tao Zhang 1,2 and Ying Zhang 1,2Round 1
Reviewer 1 Report
This paper proposes a novel signal processing method to solve the problem that the scattered GNSS signal is pretty weak, and realizes the moving target detection in GNSS-S radar. Through the illustration of simulation and field experiments, the proposed method can detect the moving target when the GNSS signal is utilized as radiation resource. However, there are also some details need to be improved:
1. Whether the tm in Line 208 denotes the tm in equation (8)? Please unify the all statements. And the Pi in Line 257 has the same problem as the above.
2. The font size in all equations is different from that in text.
3. Whether the quadratic differentiation processing in Line 227 is a recognized classical method or not? And there is not marked literature to explain the theorem of this method. Therefore, the transformation from equation (11) to (12) is very vague for reader.
4. What’s the definition of SNR in Table 2? Before coherent integration or after coherent integration. Whether the SNR is exorbitant? And please presents the typical SNR value in GNSS-S radar.
5. The phase differentiation method in Line 284 is not expounded. And please state whether the variation range ±45° after processing can be smaller? And what effect the smaller variation range will generate?
6. The Figure 20 is too small, and the marker is too large!
7. In Figure 21(b), the blue variation curve of the method in this paper is descended with the increasing of integration time. Please give the reason!
8. The sentence in Line 418 “It can be seen that when the moving speed of the target increases, the effect of noncoherent accumulation is better than that of coherent accumulation” is not in accordance with the result in Figure 21(b). The figure shows that the coherent can get better result.
Author Response
Please see the attachment.
Author Response File: 
Author Response.docx
Reviewer 2 Report
In this manuscript, a weak signal processing method for moving target of GNSS-S Radar based on amplitude and phase self-correction is proposed. There have some suggestions that authors should be considered.
1. The state-of-art of signal processing in GNSS-based passive radar should be updated. Many new methods are proposed, such as the Radon-Fourier transform algorithm. A comparison experiment should also be carried out considering the new method and your method.
2. In figure 16 and figure 19, there still have some data on the left of the zero distance part, why?
3. Figure 20 should be replaced.
4. Discussion part is too simple.
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
All comments have been responded to.
Reviewer 2 Report
It is OK to publish.
