Pseudo-Spectral Time-Domain Method for Subsurface Imaging with the Lunar Regolith Penetrating Radar
Round 1
Reviewer 1 Report
This article presents the PSTD-RTM method for radar imaging and shows its effectiveness in processing data collected by lunar-regolith penetrating radar (LRPR) in the laboratory. The method makes it possible to significantly reduce computational resources and quickly predict the location of an object in the subsurface area. The authors provide a very detailed and understandable description of the method as well as the results obtained during data processing. The results obtained can be useful for planetary subsurface exploratins. I have just a few minor comments:
1. The title of the article does not reflect its content and is difficult to understand. I would recommend such a title or something like this: "Pseudo-spectral time-domain method for subsurface imaging with the lunar-regolith penetrating radar".
2. In Figures 6 and 8, it is visually very difficult to find the differences between images (a-e) and (f-j), so I suggest leaving only two images, for example (a) and (f), and describe the difference in the text. Otherwise, it is necessary to note the differences in the figures.
Author Response
General comments. This article presents the PSTD-RTM method for radar imaging and shows its effectiveness in processing data collected by lunar-regolith penetrating radar (LRPR) in the laboratory. The method makes it possible to significantly reduce computational resources and quickly predict the location of an object in the subsurface area. The authors provide a very detailed and understandable description of the method as well as the results obtained during data processing. The results obtained can be useful for planetary subsurface explorations. I have just a few minor comments:
Authors’ Response: We thank reviewer for the time, the constructive comments, and the positive decision on our manuscript. We have already finished the response to the comments point by point, as shown below.
Comment 1. The title of the article does not reflect its content and is difficult to understand. I would recommend such a title or something like this: "Pseudo-spectral time-domain method for subsurface imaging with the lunar-regolith penetrating radar".
Authors’ Response: Thanks for the comment. Based on reviewer 1’s suggestion, this title more succinctly and concisely represents our theme to detect the lunar soil. We decided to choose the title to name this article as “Pseudo-spectral time-domain method for subsurface imaging with the lunar-regolith penetrating radar”.
Comment 2. In Figures 6 and 8, it is visually very difficult to find the differences between images (a-e) and (f-j), so I suggest leaving only two images, for example (a) and (f), and describe the difference in the text. Otherwise, it is necessary to note the differences in the figures.
Authors’ Response: Thanks for the comment. Because the processing process involves the signal processing of the project, the five groups of images will be slightly similar. The repeated work also shows that we has carried out many laboratory reliability tests before Chang’E-5 explore the moon. Although the deviation of these pictures is small, it mainly reflects that they are reliable measurement data in the processing process. Once the presentation of these data is deleted, readers may not be able to better understand the importance of lunar exploration. Therefore, Both measurements and algorithms possess equal importance. Here, we would like to thank the reviewers for his suggestions. We also hope to present more experimental measurements to readers, not limited to algorithms.
Reviewer 2 Report
In my opinion the sentence "the lunar surface soil can be usually considered as a non-magnetic" (line 214) may not be correct because the ubiquitous lunar basalt is a magnetic material (it is magnetite-bearing, a mineral with high magnetic susceptibility).
Author Response
General comments. In my opinion the sentence "the lunar surface soil can be usually considered as a non-magnetic" (line 214) may not be correct because the ubiquitous lunar basalt is a magnetic material (it is magnetite-bearing, a mineral with high magnetic susceptibility).
Authors’ Response: We thank reviewer for the time, the constructive comments, and the positive decision on our manuscript. We modify the content as below:
The ubiquitous lunar basalt may be a magnetic material, which shows a magnetite-bearing mineral with high magnetism. However, according to the previous research analysis of the lunar data from CE-1 to CE-4 Lander, the lunar surface soil [16],[22],[23] can be usually considered as a non-magnetic, isotropic media with the relative permittivity of εr = 3.
Here we would like to thank reviewer for pointing out the details about the specific materials. It is necessary for us to work hard for the detections in outer space with more measurements in the earth lab.
Reviewer 3 Report
The article is well written and conceived: I have no major objections to it.
Author Response
General comments. The article is well written and conceived: I have no major objections to it.
Authors’ Response: We thank reviewer for the time, the constructive comments, and the positive decision on our manuscript.
