Multi-Scale Encoding (MSE) Method with Spectral Shape Information (SSI) for Detecting Marine Oil-Gas Leakages

Round 1

Reviewer 1 Report

The advantage of this method is that the Oil and gas leakages could be correctly detected by using a small set of samples. The algorithm in this paper has low complexity and good results. Wish the author had described the dataset in more detail.

Author Response

Dear Reviewer 1,

 

Thanks for your acceptance to our manuscript. Following your advice, we added more detailed descriptions about the datasets.

 

Wish you all the best.

 

Dong Zhao.

Reviewer 2 Report

I. Major comments:

I.1. You should add 1 paragraph to describe the level of satellite images which are used in your paper in section 2. If you use the input data for your algorithm at TOA level, then the spectral shape of the objects will be very confused with each other. If you use surface reflectance data of these images, the atmospheric correction method should be added.

I.2. You should add a flowchart of oil leakage detecting from MSI and HSI

II. Minor comments:

Line 24. hyperspectral image (HSI) and multispectral image (MSI)

Author Response

Dear Reviewer 2,

 

Thanks for your comments and suggestions. Following your advice, we revised the manuscript according to your suggestions.

 

I.1. You should add 1 paragraph to describe the level of satellite images which are used in your paper in section 2. If you use the input data for your algorithm at TOA level, then the spectral shape of the objects will be very confused with each other. If you use surface reflectance data of these images, the atmospheric correction method should be added.

 

Thanks for your suggestion. It is our fault for not considering the data level before. Following your advice, we added a paragraph at the end of section 2 where the process of the proposed method were described to mention the data level and atmospheric correction method. The added paragraph were marked as blue. Hope it’s suitable to solve the problems.

 

I.2. You should add a flowchart of oil leakage detecting from MSI and HSI

 

Thanks for your suggestion. We are sorry that the original Figure 4 does not accurately describe the process of the MSE method with SSI. Following your advice, we drew a new flowchart of the detection method (Figure 1). Hope its satisfactory.

 

Figure 1. The flow chart of ground object detection by the MSE method with SSI.

 

Line 24. hyperspectral image (HSI) and multispectral image (MSI)

 

Thanks for your notice. It was a apparent mistake. We had revised the content.

 

Finally, we really appreciate your recognition. Wish you all the best.

 

Dong Zhao.

Author Response File: Author Response.docx

Reviewer 3 Report

Please, check verbal tense of the article.

See my comments attached.

Comments for author File: Comments.pdf

Author Response

Dear Reviewer 3,

 

Thanks for your suggestions to our manuscript. Following your advice, we revised the manuscript and answered your questions here.

 

(1) Some sub-figures' numbers use "AB", and some sub-figures' numbers use "ab". Modify to a unified style.

 

We are sorry for these mistakes. The figures were formed by we two authors. Thus the sub-figures’ numbers were inconsistent. We have revised all the figures and uniformed the numbers.

 

(2) Line 380："(figure 11 (a))"should not appear in formal academic expression. "in Fiugre11a"or "(Figure 11a)". Similar problems need to be corrected.

 

Thanks for your suggestion. It is really our mistake in manuscript editing. Now we have revised the manuscript by correcting the problems (marked in blue).

 

(3) Variable names should be unified in italics.

 

We are sorry for the inconsistent variable names. In the manuscript (section 2.2 ad 2.3), the most of variables were edited in the normal font of Remote Sensing. In fact, they should be italics. Following your advice, we revised the manuscript. The variable names were unified in italics.

 

(4) Keep the text in the picture clear.

 

We are sorry for the blurry text in the pictures. We checked the manuscript and found that the text of spectral curve in Figure 9, Figure 11, and Figure 14 were blurry. Now, we fixed the problems and the resolutions of the figures were adjusted to 300 dpi. Hope its satisfactory.

 

(5) Why do images come out first and then introductory text. Adjust to the correct order.

We are sorry for the editing mistakes. We scanned the manuscript again and found the Figure 2, Figure 3, Figure 4, Figure 5, Figure 6, Figure 7, Figure 8, Figure 9, Figure 11, and Figure 13 appeared in wrong order. We had fixed the problems and put them after the introductory text.

 

Wish you all the best.

 

Dong Zhao.

Reviewer 4 Report

This  proposed a multi-scale encoding (MSE) method with spectral shape information (SSI) to detect the oil slicks in remote sensing images.It looks interesting. The narrative is reasonable.I suggest accept it after optimization:

(1) Some sub-figures' numbers use "AB", and some sub-figures' numbers use "ab". Modify to a unified style. 

(2) Line 380："(figure 11 (a))"should not appear in formal academic expression. "in Fiugre11a"or "(Figure 11a)". Similar problems need to be corrected.

(3) Variable names should be unified in italics.

(4) Keep the text in the picture clear.

(5) Why do images come out first and then introductory text. Adjust to the correct order.

Author Response

Dear Reviewer 3,

 

Thanks for your suggestions to our manuscript. Following your advice, we revised the manuscript and answered your questions here.

 

(1) Some sub-figures' numbers use "AB", and some sub-figures' numbers use "ab". Modify to a unified style.

 

We are sorry for these mistakes. The figures were formed by we two authors. Thus the sub-figures’ numbers were inconsistent. We have revised all the figures and uniformed the numbers.

 

(2) Line 380："(figure 11 (a))"should not appear in formal academic expression. "in Fiugre11a"or "(Figure 11a)". Similar problems need to be corrected.

 

Thanks for your suggestion. It is really our mistake in manuscript editing. Now we have revised the manuscript by correcting the problems (marked in blue).

 

(3) Variable names should be unified in italics.

 

We are sorry for the inconsistent variable names. In the manuscript (section 2.2 ad 2.3), the most of variables were edited in the normal font of Remote Sensing. In fact, they should be italics. Following your advice, we revised the manuscript. The variable names were unified in italics.

 

(4) Keep the text in the picture clear.

 

We are sorry for the blurry text in the pictures. We checked the manuscript and found that the text of spectral curve in Figure 9, Figure 11, and Figure 14 were blurry. Now, we fixed the problems and the resolutions of the figures were adjusted to 300 dpi. Hope its satisfactory.

 

(5) Why do images come out first and then introductory text. Adjust to the correct order.

We are sorry for the editing mistakes. We scanned the manuscript again and found the Figure 2, Figure 3, Figure 4, Figure 5, Figure 6, Figure 7, Figure 8, Figure 9, Figure 11, and Figure 13 appeared in wrong order. We had fixed the problems and put them after the introductory text.

 

Wish you all the best.

 

Dong Zhao.

Reviewer 5 Report

(1) In section "2.1. Marine oil-gas leakages", introduction of oil and gas leakage should not be stated in such a complicated manner. In manuscript, it needs to be condensed and simplified. However, it should be noted that the problem also needs to be clearly described.

(2) The physical meaning of the parameters in all Equations needs to be explained in detail. Only in this way can readers continue to carry out relevant research in the future.

(3) Detials of the study area needs to be added in the manuscript. This section needs to be placed as the section 2. 

(4) The method used in manuscript can be used to identify oil spills. This is because there is indeed a certain difference between oil slick and seawater (such as electromagnetic wave reflection characteristics, etc.). However, can it be used to identify gas leakage? You know, gas leakage effect the sea level little. It not, should the title be changed? Please explain it clearly.

(5) In addition, the remote sensing methods in the manuscript may indeed be used to identify oil spills. However, can we have the courage to assess the amount of oil spills and the severity of oil spill accidents? If not, please explain it in the manuscript and add more additional quantitative data to the manuscript. This is because purely qualitative descriptions play a limited role in the treatment of oil spill accidents.

(6) There are some flaws in the manuscript that need to be corrected and explained by the authors. For example, in Figure 13, there is no title with horizontal and vertical coordinates. Of course, other similar flaws in the manuscript should be checked and corrected by the author.

(7) Some previous investigations need to be cited to support the statement in Line 49 of manuscript. The following references should be cited: (1) Environmental Science and Pollution Research, 2022, 29(51): 77737-77754; (2) Environmental Science and Pollution Research, 2023, https://doi.org/10.1007/s11356-023-26279-9; (3) Journal of Ocean Engineering and Science, 3(1), 2018, 38-48.

Author Response

Dear Reviewer1,

 

Thanks for your suggestions to our manuscript. Following your advice, we revised the manuscript and answered your questions here.

 

• In section "2.1. Marine oil-gas leakages", introduction of oil and gas leakage should not be stated in such a complicated manner. In manuscript, it needs to be condensed and simplified. However, it should be noted that the problem also needs to be clearly described.

 

Thanks for your advice. We scanned the section 2.1 again and found the content of this section was messy. We reconstructed and condensed this section. Now, section 2.1 is described by 1) the sources of the oil-gas leakages (paragraph 1); 2) the features of oil slicks and gas leakages (paragraph 2). Hope the condensed context was clear.

 

• The physical meaning of the parameters in all Equations needs to be explained in detail. Only in this way can readers continue to carry out relevant research in the future.

 

Following your advice, we revised the paragraphs of describing equations. The physical meaning and value range of the parameters (T^M, N, alpha, T^LH, T^UH, T^S, beta, S) were provided in the manuscript.

 

• Detials of the study area needs to be added in the manuscript. This section needs to be placed as the section 2. 

 

Thanks for your advice. We reconstructed the “Section 3. Results” following your suggestion. Every experiment was organized as the section 2. Details of the study areas were added at the beginning of each section.

 

• The method used in manuscript can be used to identify oil spills. This is because there is indeed a certain difference between oil slick and seawater (such as electromagnetic wave reflection characteristics, etc.). However, can it be used to identify gas leakage? You know, gas leakage effect the sea level little. It not, should the title be changed? Please explain it clearly.

 

Thanks for your comments. Your concerns about the application scenarios of the proposed method was absolutely reasonable. We would answer your questions here. The goal of our research was to detect marine incidents such as oil spill and natural gas leakages which was harmful to the environment. Floating oil slicks were translucent. Their spectral signals were greatly affected by seawater. The spectra of oil slicks and seawater were very similar (Figure 14 in the manuscript). Mining stable and abundant spectral differences was the ultimate goal of the detection method. However, gas leakages would make a splash on the sea surface by methane. It changed the spectral signals of the seawater a lot. In the satellite images, the natural gas leakages had more obvious spectral differences than oil slicks (Figure 14 in the manuscript). That was why the gas leakage detection result looked so clean (Figure 11 in the manuscript) and the oil spill detection results usually contained error pixels (Figure 5-10 in the manuscript). The proposed method was designed to translate the spectral details and mine the spectral differences. It was suitable for detecting both oil slicks and gas leakages. Thus, we would like to save the title of the manuscript. Hope the explanation was satisfactory.

 

• In addition, the remote sensing methods in the manuscript may indeed be used to identify oil spills. However, can we have the courage to assess the amount of oil spills and the severity of oil spill accidents? If not, please explain it in the manuscript and add more additional quantitative data to the manuscript. This is because purely qualitative descriptions play a limited role in the treatment of oil spill accidents.

 

Thanks for your questions. Sorry, the proposed method was not able to assess the amount of oil spills. The aim of the research was to detect oil-gas leakage objects and determine the incident scopes. Thus, in the experimental results, the oil-gas leakage detection results only marked the incident pixels instead of their actual oil thicknesses or gas leakage volume. However, it could be noticed that the proposed method could identify different thicknesses of oil slicks in airborne hyperspectral images (Figure 10 in the manuscript). In addition, it could differentiate emulsions from normal oil slicks in Sentinel-2 images (Figure 7 in the manuscript). It was helpful for locating and evaluating the pollution. The information of oil spill and gas leakage amount was hard to obtain. We did have the quantitative data about the experimental incidents. We feel sorry that we could not conduct quantitative experiments for the proposed method. Hope the answer was satisfactory.

 

• There are some flaws in the manuscript that need to be corrected and explained by the authors. For example, in Figure 13, there is no title with horizontal and vertical coordinates. Of course, other similar flaws in the manuscript should be checked and corrected by the author.

 

We are sorry for the flaws in the figures. We checked the manuscript again and found the Figure 5, 6, 7, 8, 9, 11, and 13 existed the similar mistakes. Now, we added titles for the coordinates. Hope the fixed figures were satisfactory.

 

(7) Some previous investigations need to be cited to support the statement in Line 49 of manuscript. The following references should be cited: (1) Environmental Science and Pollution Research, 2022, 29(51): 77737-77754; (2) Environmental Science and Pollution Research, 2023, https://doi.org/10.1007/s11356-023-26279-9; (3) Journal of Ocean Engineering and Science, 3(1), 2018, 38-48.

 

Thanks for your advice. These three articles are suitable for our manuscript. We sited the references in the manuscript as the followings:

12.Li, Q.; Han, Y.; Liu, X.; Ansari, U.; Cheng, Y.; Yan, C. Hydrate as a by-product in CO2 leakage during the long-term sub-seabed sequestration and its role in preventing further leakage. Environmental Science and Pollution Research, 2022, 29(51): 77737-77754.

13.Li, Q.; Wang, F.; Wang, Y.; Zhou, C.; Chen, J.; Forson, K.; Miao, R.; Su, Y.; Zhag J. Effect of reservoir characteristics and chemicals on filtration property of water-based drilling fluid in unconventional reservoir and mechanism disclosure. Environmental Science and Pollution Research, 2023, 20(3):1614-7499. doi: 10.1007/s11356-023-26279-9.

14.Cheliyan, A.S.; Bhattacharyya, S.K. Fuzzy fault tree analysis of oil and gas leakage in subsea production systems. Journal of Ocean Engineering and Science, 2018, 3(1): 38-48. doi: 10.1016/j.joes.2017.11.005.

 

 

Wish you all the best.

 

Dong Zhao.

Round 2

Reviewer 5 Report

The manuscript can be accepted for publication now.