A Review of High-Sensitivity Tracking Techniques for Satellite Navigation Signals

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This paper systematically reviewed and analyzed the latest advancements in high-sensitivity tracking algorithms under different tracking methods, while also providing insights into future trends in this field. I recommend this paper for publication if the requested items are modified.

1. Suggest providing full expressions of abbreviations, such as “UAV”, “GPS” and “MEMS”, when they are first used in the paper. Additionally, please address grammatical issues throughout the manuscript to enhance readability.
2. For the research on improving tracking loops with EKF, there should be relevant work done by other scholars. Please include appropriate supplements in the paper.
3. Suggest adding references to the models in the paper. For example, formulas (6)-(9).
4. This paper mentions that ‘recent developments have shifted toward carrier phase tracking due to increasing demands for higher-accuracy positioning’. Please provide the latest research on carrier phase tracking.
5. Please address the typographical issues in Table 1. In addition, two different implementations of the super-tight integration system, i.e., Non-Coherent Super-Tight Combination and Coherent Super-Tight Combination, are mentioned in Table 1. However, the paper does not cite relevant research to describe these two methods.
6. Ensure proper citation formatting according to MDPI standards.

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

1. In the conclusion and outlook sections, please make sure to highlight the innovative aspects discovered in this study, as well as the current issues, potential future research paths, and methods. Avoid merely restating optimization directions already noted in existing literature. The current conclusions lack innovation.

2. Revise the wording in the abstract (Lines 8-12) to closely align with the article's theme and clearly specify the optimization directions.

3.Modify the article's logical structure according to the RS submission template, for example: 1. Introduction, 2. Method 2.1 Tracking Methods, 5. Conclusion.

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

The paper described a review of high-sensitivity tracking techniques for satellite navigation signals. There are some issues that need to be addressed carefully.

1. In the introduction section, the innovation and contribution of the paper should be more clearly described to reflect its value.
2. It is recommended that the timing, authors, strengths and weaknesses of the different types of tracing methods be presented in tabular form.
3. The formatting and presentation of the paper should follow the format requirements of RS journal to make the paper more readable.
4. The content of Table 1 is not clearly presented. It is recommended that it be revised.

Author Response

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Author Response File: Author Response.docx

Reviewer 4 Report

Comments and Suggestions for Authors

This paper provides a comprehensive overview of the latest advancements in high-sensitivity satellite navigation signal tracking techniques, covering closed-loop tracking, open-loop tracking, and Direct Position Estimation (DPE). The paper is structured clearly and covers a wide range of content. However, there are some issues regarding the depth of professional knowledge, presentation of experimental results, and rationality of experimental arrangements, requiring substantial revisions.

1. Some contents, such as the specific implementation details of closed-loop and open-loop tracking, are described superficially, lacking in-depth technical analysis. It is recommended to add mathematical derivations and discussions on the implementation details of key algorithms to enhance the professional depth of the paper.
2. The paper does not fully cover the latest research achievements, especially recent progress in DPE and deep learning-assisted tracking. It is suggested to supplement these areas to reflect the latest technological developments.
3. The paper lacks specific experimental results and analyses, particularly comparisons of the performance of different tracking techniques. It is recommended to add an experimental section, comparing the performance of different tracking techniques in different scenarios to validate the effectiveness of the techniques described in the paper.
4. Due to the lack of experimental results, the rationality of the experimental arrangement cannot be directly assessed. However, when adding the experimental section, it is recommended to pay attention to the scientificity and rationality of the experimental design to ensure the reliability and validity of the experimental results.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

The author has well addressed all my comments. I have no more concerns.

Reviewer 4 Report

Comments and Suggestions for Authors

I have no further comment. I recommend to accept it.