A Novel Radar Detection Method for Sensing Tiny and Maneuvering Insect Migrants
Round 1
Reviewer 1 Report
- In Fig. 5, it is fair to compare detection probability of MTD, KS-MTD, FrFT and the proposed DP-FrFT. The authors can consider different probability of false alarm.
- As the authors considered maneuvering insects. This implies that targets can accelerate and decelerate. And this cause the target's radar cross section (RCS) to vary over time. But Fig.5 did not depict fluctuating targets. Clarification is required.
Author Response
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Reviewer 2 Report
The paper is interesting. The topics are well covered and the proposed solution is clearly described.
Just a few remarks:
Lines 83 to 87: Correct the number of the sections;
Figure 1 (a) Please explain better what the ordinate units are;
Line 125: a "v" should, perhaps, be eliminated.
Author Response
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Reviewer 3 Report
The manuscript describes a novel radar method to detect range- and velocity-changing insects at altitudes. The method employs both dynamic programming track-before-detecting algorithm (DP-TBD) and fractional Fourier transform (FrFT). The former method extracts targets’ tracks and presents their rough velocities and accelerations, contributing to reduction of computational cost. Then, FrFT method is applied to only pre-selected tracks and accurately estimate final targets’ velocities and accelerations. The reviewer felt that section 3.3 especially is mathematically beautiful and found that the proposed method is sound.
Followings are minor comments for possible improvements.
(Introduction and somewhere before Conclusion) Drake and Wang (2019) (Ref. 2 in the manuscript) reports a method to estimate an insect velocity by a X-band non-coherent vertical looking entomological radar. Please refer to this in Introduction. The reviewer would like also to know the accuracy of velocity and acceleration estimation, and compare your result with Drake and Wang’s, please. It would be better if you could compare other characteristics of two types of radar as well in Discussion.
(Line 33) all-weather: No microwave radar can detect flying insects in rain.
(Lines 83-87) All “Section”s are zero. Please correct them.
(Section 2.1) Readers do not know when, where, how did you collect these evaluation data. Please describe experiment conditions. Are these obtained with the new method or traditional MTD? Do “200 datasets” mean 200 nights? (line 101). For me, Figure 1 and 2 are a part of results which may be moved to section 4.2.
(Figure 1) The figure needs scale color bars.
(Line 160) Characters [ and ] are necessary for 21 in this line.
(Line 253) I don’t know what CA-CFAR.
(Line 273) the black curve?? >> the red dotted line.
(Line 323) CPI >> coherent processing interval (CPI)?
(Table 3) Please add beam width.
(Figure 8a) I understand the figure shows low SNR signals. But it would be easy to understand if you changed its coloring in order to recognize signals. The figure shows very low contrast and readers cannot find any insects on the image.
(Line 325) the first time: I don’t think this study is for the first time. Reference 2 is earlier.
Author Response
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