Semi-Airborne UAV-TEM System Data Inversion with S-Plane Method—Case Study over Lake Baikal

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The topic is certainly of interest to the journal, and the TEM data appear to have been taken, processed and interpreted in a reasonable manner. Below, I have outlined several suggested comments as constructive criticism and hope that they will be helpful to the authors in improving the manuscript.

- Image (a) is missing from figure 1

- Several softwares are used that are not mentioned in the article, such as perhaps Oasis Montaj, Voxler.....

- In figure 3a the north and scale are missing.

- Figure 10. Improve it, you can see the cutout at the bottom and I would include some interpretation in that 3D.

- Figure 12 improve it and add north and scale

Author Response

We thank the respected reviewer for his comments; the attached file contains the answers.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The article presents a demonstration of UAV transmission electron microscopy ground source measurements on Lake Baikal. Lake Baikal has a unique geoelectric environment where low resistivity lacustrine sediments are located under relatively isotropic bodies of water. The detection depth is from 50 to 300 m, divided into layers and blocks. This article also introduces a new version of the SibGIS system, as previously described in the documentation. From this paper, we can conclude that UAV-TEM technology can already replace the traditional terrestrial technique electromagnetic measurement.

There are a few issues that need to be identified:

(1) The selection of the first attenuation curve The author is different, please give an explanation. 

(2) Inversion should be compared using conventional algorithms.

(3) How do readers know that the test results are true? According to the question about, please modify the paper.

Author Response

Dear reviewer, we did not understand the first comment, but tried to answer the other two. Thank you for your attention to our article.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The paper presents quite an interesting investigation of the geological structure of one region of Baikal Lake.
The presented method looks promising, and the authors show some good findings. At the same time, there are several comments the authors should take into account:

First of all, as far as I understand, all the measurements were made during wintertime. Ice conductivity is known to be dependent on temperature and to differ from the one for water. Why do not the author include the layer of ice in their models?

How do the authors evaluate the wind impact during a snowstorm? Wind should incline the antenna rope increasing its altitude over the surface. What is the error introduced by the antenna location?

Do figures 1b and 1f make sense? I believe the technical details of the instruments are enough. It is better to fit all the panels in Fig 1 to each other to make the figure neat.
What is the meaning of error values in Table 1? How does the transmitter provide a pulse duration of 0.01 s with errors higher than 1s?
I believe the mention of the system produced by A.K. Zakharkin should be accompanied by a reference.
The specifications of the receiving loop given in Table 3 can be omitted in text (lines 98-105)
What do you mean by "continuously resisting TEM signals"? Probably it should be "receiving". (line 120)
What does it mean "Each reading is saved to a separate file, which in turn is saved to a separate file for each profile"? (lines 127-128)
The sentence in (lines 151-155) is hard to understand. Please change it.
"It allows to, increase time range within the signals are recorded confidently up to a time of 700–800 μ s (Fig. 4), compare to 150 μ s available with an older instrument [2, 8], which significantly reduced the depth of investigation and accuracy of solving inverse problems"
Introducing part of 3.1 (lines 174-207) should be rewritten: split is for several smaller parts and please check the language.

The symbol of tilted m is introduced twice: in lines 251 and 254. Is the symbol typed properly? The tilt seems to have a wrong relative position.
Lines 257 and 261 seem to have some missed symbols.
The statement of lines 269-271 should be accompanied by a reference
Could the authors comment on the last column of Table 4, especially its last value?
Add the figure 6 caption with the information about both the show curves. Sign the curves in Fig 6b. I recommend 20 Ohm, 100 Ohm, and 200 Ohm instead of 1,2,3.
Add ticks on the Y-axis at each 10 meters. What is designed by "S" near the quantity Sτ (X-axis)?
Table 5 shows 4 layers. Why is it called the "five-layer model" in the text and figure 6?
Correct the misprint in line 293: "fore-layered"
Table 6, Model 1: H for the 2nd layer should be 100 m
Figure 7: Add panel letters to each of the three shown points to help the reader find the corresponding curve
Explain the difference between the location of bottom sediments (100-260) and the depth values shown in Fig 7d (40-160m). What does "surface of bottom sediments" mean?

General comment on figures: all of them should be of the same style. Add a black frame to all of them or remove (which is better) from every figure. Do not split your figure between pages. In that case it is better to have a couple of smaller neat figures, than a big ugly one.

Comments on the Quality of English Language

Please check the text carefully. Currently it is full of mistakes, typos and bad formulations.

Author Response

The authors thank the reviewer for valuable remarks and comments. We have tried to correct or respond to all of these comments, and this has made the article much better. The answers are in the attached file.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

These comments have not been considered:

Several softwares are used that are not mentioned in the article, such as perhaps Oasis Montaj, Voxler.....

- In figure 3a the north and scale are missing.

I disagree with the authors:

For data processing, only our homemade software was used that implements the algorithm described in the article. Other software was used only for the design of illustrations. Since data visualization could be done in anything, we think thar mentioning software products that are not related to the result is not necessary.

I disagree with the authors: All software used has to be indicated

Author Response

Ok, since the respected reviewer considers this important, we indicated in the captions to the figures what software product the visualization was performed in.