Development of a Numerical Simulation Model to Support the Design of a Ship–Satellite Communication System for Autonomous Marine Navigation

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The study delves into two approaches to examine a possible improvement of a ship-satellite communication system for autonomous marine navigation, which in my opinion is an interesting topic. However, the manuscript could benefit from some revisions.  

I find the methodology section to be a bit overwhelming with information, making it easy for the reader to lose track. Additionally, the disparity in length between the methodology (8 pages) and results (2 pages) sections stands out. Furthermore, there's a need for a more extensive discussion.

Attached you can find the manuscript with some comments.

Comments for author File: Comments.pdf

Author Response

Please see the attachment

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The work conducts the numerical analysis focused around the assessment of the viability of satellite targeting through a pointing system. The topic is interesting and the authors have done solid work. However, the work lacks of novelty, and the authors were unable to show clearly about their contribution on innovation of methodology beyond the numerical analysis. Here are some comments on the manuscript:

1. There are too many background descriptions about intelligent ships in the Introduction section, but there is little content about the ATP system. In fact, the service scope of low orbit satellite communication systems is far from limited to MASS, and traditional ships also have a large demand. The correlation between the MASS background and the research content of this work is relatively low, , and the relevance with the ATP system is more direct.

2. Figure 9 shows the control loop flowchart used by the authors in their simulation, but there are few details in the figure and the author's experimental ideas are not fully explained in conjunction with this figure.

3. All curves in Figure 17 show a clear unified trend of change, but the authors did not conduct sufficient analysis of the figure.

4. The author mentioned in the abstract that "the system and results show that the pointing phase is influenced less by ship motions and more by errors that occurred during satellite position and ship motions acquisition process." However, I did not see any intuitive figures or tables in Section 3 to support this conclusion.

5. The work lacks an introduction to the related works and current development status within the target research area.

6. The Introduction section lacks a summary of the main research contributions of this work.

7. The Conclusion section lacks a summary of the limitations of this work and potential future work directions.

 

Comments on the Quality of English Language

The writing of the manuscript is good, but there are still some minor errors that need to be carefully checked. e.g. The abstract mentions 'The minimum requested pointing accuracy is 100 mrad', is mrad incorrect here?

 

 

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

This paper proposed an ATP model with two Degrees of Freedom (DoF). The author points the error analyzed in order to verify the possibility to enable data exchange between the two platforms. However, considering the innovative of this paper, it is cannot be accpeted for publication by current version. Some reasons as follows:

1、There is insufficient literature analysis on the current research status both domestically and internationally, especially in the field of ship-satellite communication. Suggest rearranging the chapters on the current research status both domestically and internationally.

2、Figure 1 does not have a corresponding description or reference in the main text.The resolution of Figure 12 is not very clear, it is recommended to replace it. The meaning of the x and y coordinates is unclear and needs to be explained in the text.

3、Many parameters in the paper have not been given specific definitions and explanations, such as Formulas (1) to (6) and others; Many symbols in Figure 9, such as 0, fcn, C, X, etc., have meanings for illustration. Suggest providing a table to summarize the variable symbols and their meanings throughout the entire text.

4、In Section 2.3, although the author briefly introduced ship motion and its impact on measurement accuracy. However, there is a lack of introduction to ship motion models and hydrodynamics. In addition, the article only considers the influence of waves on their measurement errors, and usually ships sailing at sea are affected by multiple factors such as wind, waves, and currents, so wind, waves, and currents should be considered.

5、Usually, ship motion is six degrees of freedom, but in Section 2.3, the author only introduced and provided the motion of the ship in the Roll, Pitch, and Yaw directions. In order to achieve these three degrees of freedom? Can the ship motion with only these three degrees of freedom accurately represent the impact of ship motion on measurement accuracy? The author did not provide a reason or explanation.

6、In line 265, "Resulting in ∆ Az e ∆ El graph as follow", what does letter e mean?

7、In the third section, there is only "3.1 Implementation of the optical system to improve pointing accuracy", so there is no need to keep this secondary title.

8、The conclusion lacks relevant content on insufficient research and future prospects in the paper. It is recommended to supplement it.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

I am generally satisfied with the manuscript in present form. 

 

Reviewer 3 Report

Comments and Suggestions for Authors

The authors have adequately addressed my comments. I would like to recommend acceptance of the paper.