Efficient Underwater Sensor Data Recovery Method for Real-Time Communication Subsurface Mooring System

Round 1

Reviewer 1 Report

Please carefully justify and explain on all comments.

1. In the introduction, you need to connect the state of the art to your paper goals. Please follow the literature review by a clear and concise state of the art analysis. This should clearly show the knowledge gaps identified and link them to your paper goals. Please reason both the novelty and the relevance of your paper goals. Clearly discuss what the previous studies that you are referring to.
What are the Research Gaps/Contributions? Please note that the paper may not be considered further without a clear research gap and novelty of the study.


2. Please underscore the scientific value-added to your paper in your abstract. Your abstract should clearly state the essence of the problem you are addressing, what you did and what you found and recommend.
That would help a prospective reader of the abstract to decide if they wish to read the entire article.

3. In your discussion section, please link your empirical results with a broader and deeper literature review.

4. Please make sure your conclusions' section underscores the scientific value-added of your paper, and/or the applicability of your findings/results. Highlight the novelty of your study.
In addition to summarising the actions taken and results, please strengthen the explanation of their significance. It is recommended to use quantitative reasoning comparing with appropriate benchmarks, especially those stemming from previous work.

5. Please consult the journal's reference style for the exact appearance of these elements, and use of punctuation and capitalisation.
Bibliography style is not always consistent, please check the reference section carefully and correct the inconsistency.

6. Please eliminate those multiple references. After that please check the manuscript thoroughly and eliminate ALL the lumps in the manuscript. This should be done by characterising each reference individually. This can be done by mentioning 1 or 2 phrases per reference to show how it is different from the others and why it deserves mentioning.

7. Please eliminate the use of redundant words. Eg. In this way, Recently, Respectively, therefore, currently, thus, hence, finally, to do this, first, in order, however, moreover, nowadays, today, consequently, in addition, additionally, on the other hand, furthermore. – Please revise all similar cases, as removing these term(s) would not significantly affect the meaning of the sentence. This will keep the manuscript as CONCISE as possible. Please check ALL.
Avoid beginning or end a sentence with one or a few words, they are usually redundant. E.g. Today,.Avoid beginning a sentence with a conjunction term, e.g. And, Which, Where, Because.

8. Please check if you have cited each Eq./Fig./Table/Section with its SPECIFIC NUMBER you referred in the TEXT? E.g. It should be stated in the text: …..as shown in Fig. 1 (Fig. capitalize). Please avoid stating ambiguous referencing e.g. …...is as follow…; based on the above/below table/fig.

9. Please use SI unit. E,g, m instead of meter, t instead of tons. d instead of day, y instead of years or yr, h instead of hours, M instead of million, kg instead of kilogram (including those in figures/tables) and leave a space between the value and unit.

Author Response

Response to Reviewer 1 Comments

Thank you very much for your comments and professional advice. Base on your suggestion and request, we had made corrected modifications on the revised manuscript. Please display all tags in Word's revision mode when reviewing the revised manuscript. We hope that our work can be improved again. Furthermore, we would like to show the details as follows:

 

Point 1: In the introduction, you need to connect the state of the art to your paper goals. Please follow the literature review by a clear and concise state of the art analysis. This should clearly show the knowledge gaps identified and link them to your paper goals. Please reason both the novelty and the relevance of your paper goals. Clearly discuss what the previous studies that you are referring to.

What are the Research Gaps/Contributions? Please note that the paper may not be considered further without a clear research gap and novelty of the study.

Response 1: In the introduction section of the paper, we have described the shortcomings of the previous research, and we have added the novelty of this study according to the comments of reviewers, please see Lines 97 to Lines 101 in the manuscript. 

 

Point 2: 2. Please underscore the scientific value-added to your paper in your abstract. Your abstract should clearly state the essence of the problem you are addressing, what you did and what you found and recommend.

That would help a prospective reader of the abstract to decide if they wish to read the entire article.

Response 2: We have rewritten the abstract according to your suggestion, please see Lines 33 to Lines 56 in the manuscript. The new abstract underscores the scientific value-added to this paper and answers other questions in this section. 

 

Point 3: 3. In your discussion section, please link your empirical results with a broader and deeper literature review.

Response 3: There is no discussion section in the manuscript. I'd want to know if this section is necessary. If so, we will supplement it later.

 

Point 4: Please make sure your conclusions' section underscores the scientific value-added of your paper, and/or the applicability of your findings/results. Highlight the novelty of your study.

In addition to summarising the actions taken and results, please strengthen the explanation of their significance. It is recommended to use quantitative reasoning comparing with appropriate benchmarks, especially those stemming from previous work.

Response 4: According to the reviewer's suggestion, we underscored the scientific value of this paper in the conclusion section, please see Lines 415 to Lines 430 in the manuscript. We highlighted the advantages of our research. The novelty of this paper was described in the abstract and introduction. 

 

Point 5: Please consult the journal's reference style for the exact appearance of these elements, and use of punctuation and capitalisation.

Bibliography style is not always consistent, please check the reference section carefully and correct the inconsistency.

Response 5: We have checked the reference section and corrected the inconsistency, such as the first reference, please see Lines 454.

 

Point 6: Please eliminate those multiple references. After that please check the manuscript thoroughly and eliminate ALL the lumps in the manuscript. This should be done by characterising each reference individually. This can be done by mentioning 1 or 2 phrases per reference to show how it is different from the others and why it deserves mentioning.

Response 6: We checked the manuscript thoroughly and adjusted some references. The third reference was changed by The development of a new real-time subsurface mooring (lines 66); a new reference was added in the paper, which title was A Smart Sensor Web for Ocean Observation: Fixed and Mobile Platforms, Integrated Acoustics, Satellites and Predictive Modeling (lines 67); the 11th reference was deleted, which title was Hardware design of a submerged buoy system based on electromagnetic inductive coupling; the citation position of the 20th reference is changed to lines 172; a new reference was added in the paper, which title was Hardware design of a submerged buoy system based on electromagnetic inductive coupling (lines 277).

 

Point 7: Please eliminate the use of redundant words. Eg. In this way, Recently, Respectively, therefore, currently, thus, hence, finally, to do this, first, in order, however, moreover, nowadays, today, consequently, in addition, additionally, on the other hand, furthermore. – Please revise all similar cases, as removing these term(s) would not significantly affect the meaning of the sentence. This will keep the manuscript as CONCISE as possible. Please check ALL.

Avoid beginning or end a sentence with one or a few words, they are usually redundant. E.g. Today,.Avoid beginning a sentence with a conjunction term, e.g. And, Which, Where, Because.

Response 7: We have submitted the manuscript to the English editing service of MDPI. We will eliminate the redundant words after editing completed and submit the new version. 

 

Point 8: Please check if you have cited each Eq./Fig./Table/Section with its SPECIFIC NUMBER you referred in the TEXT? E.g. It should be stated in the text: …..as shown in Fig. 1 (Fig. capitalize). Please avoid stating ambiguous referencing e.g. …...is as follow…; based on the above/below table/fig.

Response 8: We checked the manuscript and confirmed that each Eq./Fig./Table/Section has followed above format.

 

Point 9: Please use SI unit. E,g, m instead of meter, t instead of tons. d instead of day, y instead of years or yr, h instead of hours, M instead of million, kg instead of kilogram (including those in figures/tables) and leave a space between the value and unit.

Response 9: We used m instead of meter, please see Line 329, Line 336, Line 337 and Line 340.

Author Response File: Author Response.docx

Reviewer 2 Report

Review of manuscript by Peng Luo, Yuanjie Song, Xiaoyang Xu, Shaowei Zhang, Yeqiang Shu, Yonggui Ma, and Chuan Tian.   Efficient underwater sensors’ data recovery method for real-time communication subsurface mooring system

The authors describe a developed system for collecting data of underwater sensors installed on a subsurface mooring. The system transmits data to a satellite from a small surface transponder connected to the underwater data collecting system on a mooring. The system has been tested in the South China Sea during three months transmitting real-time temperature, salinity, and depth data sets.

I consider that the system developed by the authors is very interesting. The manuscript deserves publication. However minor improvements of the text are required. 

I strongly suggest that the language should be edited by a professional.

In addition, the abstract and conclusions do not reflect the description of the system presented in the main text.  Both the abstract and especially conclusions resemble commercial advertising of the product. Both should be rewritten. Parts of Introduction in the first sentences of the abstract are not needed. Conclusions should represent the essence of the manuscript. In other words, the results of the work should be presented in a very concise form.

The authors compare the data with the data from databases.  Did you do any in situ measurements during the three months of the system operation.

The black line in Fig. 15 from the Luzon Strait has nothing to do with the other data shown in the figure. Please explain the color (yellow-green-blue) field of density in the plot. Are the plotted dots the measurements made by the system?

 Eugene Morozov, Shirshov Institute of Oceanology, Russian Academy of Sciences

Author Response

Response to Reviewer 2 Comments

Thank you very much for your comments and professional advice. Base on your suggestion and request, we had made corrected modifications on the revised manuscript. We hope that our work can be improved again. Please display all tags in Word's revision mode when reviewing the revised manuscript. Furthermore, we would like to show the details as follows:

 

Point 1: I strongly suggest that the language should be edited by a professional.

 

Response 1: We have submitted the manuscript to the English editing service of MDPI, but it will take 3~5 working days. We will submit the new version as soon as editing is completed. 

 

 

Point 2: In addition, the abstract and conclusions do not reflect the description of the system presented in the main text. Both the abstract and especially conclusions resemble commercial advertising of the product. Both should be rewritten. Parts of Introduction in the first sentences of the abstract are not needed. Conclusions should represent the essence of the manuscript. In other words, the results of the work should be presented in a very concise form.

 

Response 2: We have rewritten the abstract and conclusions according to the reviewer’s advice. These following two paragraphs are the new abstract and conclusions, and we have also made the same revise in the manuscript. Please see Lines 33 to Lines 56 and Lines 415 to Lines 430 in the manuscript.

 

Abstract: The submerged buoy can effectively obtain various parameters of the ocean, which plays an important role in the research of marine physical phenomenon, marine environmental change and climate change. However, the traditional self-contained submerged buoy usually works underwater at a depth of about 100 m, and the observation data cannot be obtained before its recovery, which cannot satisfy the needs of real-time data acquisition for marine scientific research. To solve this problem, this paper proposes a real-time communication subsurface mooring system, which consists of a satellite communication buoy (SCB), Conductivity–temperature–depth sensors (CTD), and inductive coupling mooring cable. The underwater inductive coupling link collect the data from the underwater sensors and transmit the it to the SCB. Then, the data will be transmitted to station receiver via satellite communication module integrated in SCB. In order to ensure a high success rate of data recovery, the stress analysis and hydrodynamic simulation of the SCB are carried out in this paper. The results show that the SCB can maintain a relatively stable attitude in the 3-4 sea state. The attitude data obtained from subsequent sea trial is consistent with the simulation results, and the success rate of satellite communication during this period is more than 95%. In this paper, a modular embedded hardware circuit is designed to meet the functional requirements of the subsurface mooring system. An efficient data recovery strategy is also developed, which ensure that the average power consumption of system is low and the success rate of data recovery is not less than 90%, when operating in the severe sea state for a long time. The system has undergone sea trials in the South China Sea for more than 3 months from the end of 2021 to the beginning of 2022. It has transmitted more than 2034 sets of seawater profile temperature, salinity, and depth data in real-time, with a success rate of over 91% of the total sample data. The CTD data returned in real-time from our system is consistent with the data of HYCOM and World Ocean Atlas (WOA), and a cyclonic mesoscale eddy was detected in the operation area.

 

Conclusions: This paper develops a real-time communication subsurface mooring system to address the issue that it is challenging to obtain marine data in real-time. The system collects underwater sensor data via an underwater inductive modem module and then transmits the data to the station receiver via satellite communication. The hydrodynamic simulation and sea trail of the SCB are carried out in this paper. The findings indicate that, even in severe sea state, the float can maintain a relatively stable attitude with inclination angle less than 30°, enabling the maintenance of normal satellite communication. This paper also designs an efficient data recovery strategy, which ensure high data recovery efficiency and low power consumption when the system works in complex and changeable marine environment for a long time. The system has undergone sea trials in the South China Sea for more than 3 months and transmitted more than 2034 sets of underwater sensors data, with a success rate of over 91%. The CTD data returned in real-time from our system is consistent with the data of HYCOM and World Ocean Atlas (WOA), and a cyclonic mesoscale eddy was detected in the operation area. This system provides a good method for long-term real-time monitoring of marine physical phenomena and marine environmental.

 

 

Point 3: The authors compare the data with the data from databases. Did you do any in situ measurements during the three months of the system operation.

 

Response 3: We didn’t do any in situ measurements during the three months of the system operation.

 

 

Point 4: The black line in Fig. 15 from the Luzon Strait has nothing to do with the other data shown in the figure. Please explain the color (yellow-green-blue) field of density in the plot. Are the plotted dots the measurements made by the system?

 

Response 4: The black line from the Luzon Strait is plotted here to compare it with the red line from the western South China Sea, which is used to explain that the mesoscale eddy observed by mooring is generated initially by the western South China Sea. We have rewritten the caption of the Fig. 15 to make it clear, please see Lines 400 in the manuscript: “The color of the T-S diagram shows the density of the water”. As the reviewer said, with the color yellow-green-blue, the plotted dots are measured by our mooring system.

 

 

Figure 15. The temperature versus salinity (T-S) diagram for the western South China Sea at the mooring area. The color of the T-S diagram shows the density of the water. The red and black lines represent the mean T-S curves of types the western South China Sea and Luzon strait masses form WOA.

 

 

Author Response File: Author Response.docx