Coastal Assessment of Sentinel-6 Altimetry Data during the Tandem Phase with Jason-3

Round 1

Reviewer 1 Report

This paper has analysed the coastal performance of J3 and S6 during their tandem phase for outlier detection, along-track noise, bias statistics, and correlation with in-situ data, with a focus on the coastal zone and on coastal reprocessing algorithms. The SAR altimetry product of Sentinel-6 shows improved coastal monitoring capabilities compared to Jason-3, except for remaining issues related to significant wave height, which demonstrates coastal retracking algorithms. The paper needs minor revision before acceptance for publication. My detailed comments are as follows:

1

Figure 1, 2, 5, 7:

To enhance the clarity of representing data related to various distances from the coastline, it is suggested to adjust the values on the x-axis (distance from the coastline) in figures, following the format in Figure 12(a): >20km, 10-20km, 5-10km, and <5km.

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EUM PDAP HR shows strong problems in SLA data for SWH below 50 cm in the coastal zone, while the CORAL performance is not affected.

How was this conclusion reached? It can be seen from Figure 4(b) that the noise of EUM PDAP HR and CORAL is essentially consistent for SWH below 50 cm in the coastal zone.

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It is unbelievable that the SLA noise of EUM PDAP HR is so significant in Figure 5(a). Please explain the reason.

4

Figure 6

Figure 6 is not mentioned in the text.

5

Some figures are not numbered in the order in which they appear in the text, e.g., Figure 7.

Author Response

Thank you very much for the review of the paper and the comments submitted.
We have answered all of them. You will find the responses in the uploaded pdf: your comments in black followed by our responses in blue.

Author Response File: Author Response.pdf

Reviewer 2 Report

Dear authors, 

I had the privilege of evaluating your manuscript entitled "Coastal assessment of Sentinel-6 altimetry data during the tandem phase with Jason-3." I commend you on your insightful research and would like to share my feedback and recommendations to enhance the manuscript's potential for publication.

Please, find attached my comments and suggestions in this pdf. I introduced them as comments in the current manuscript.

Best Regards,

Comments for author File: Comments.pdf

Quality of English Language is good. I don't think the document needs a detailed English revision. 

Author Response

Thank you very much for the review of the paper and the comments submitted.
We have answered all of them. You will find the responses in the uploaded pdf: Your comments (as extracted from the PDF; in black) followed by our responses (in blue).

Author Response File: Author Response.pdf

Reviewer 3 Report

This manuscript presents a comparative analysis of the coastal performances of Sentinel-6 and Jason-3 altimeters during their tandem phase, considering their different processing modes. It is interesting to explore the significance of dedicated coastal retracking algorithms in enhancing the capabilities of both traditional, pulse-limited altimeters and more recent developments utilizing SAR altimetry.

To my knowledge, this manuscript is the most detailed analysis of the quality and quantity of sea level measurements in the coastal zone using both standard data and dedicated reprocessing for SAR and LR waveforms during the tandem mission of S6 and J3. The manuscript is well-written and appropriate for Remote Sensing, some further modifications to the text will need to be required prior to publication.

 

Specific comments: Please add the STUDY AREA as a separate section.

Minor editing of English language required

Author Response

Thank you very much for the review of the paper. Regarding your specific comment: The study has been done on a global scale covering all coastal areas. We don’t think a full section on the study area is necessary in this paper. Instead, we added a short introduction in the section on data to clarify the global perspective of the study.

Round 2

Reviewer 2 Report

Dear authors,

Thanks for answering all the comments and suggestions. I had just a very minor comment in one of the sentences (see attached pdf). 

Congratulations for this nice publication and clearity in the methodology and results.

Kind Regards,

Comments for author File: Comments.pdf

Author Response

Thanks for your comment. We changed the sentence as suggested.