Developments in Scope and Availability of HF Radar Wave Measurements and Robust Evaluation of Their Accuracy

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

General comments:

In this paper, the performance of a constrained iteration numerical inversion method SV is investigated, and its good accuracy and availability are further proved by providing more evidence. The method AIA is validated to distinguish swell and wind-sea components in the directional wave spectra, and how to improve the inversion performance of single radar systems is discussed. The problem of inconsistency in the accuracy assessment is pointed out and a range of statistics are proposed for use. The overall logical structure of the article is relatively clear. Some of the graphical indicators only give calculation data and fail to explain their significance clearly, which makes the superiority of the method not obvious enough. Some minor issues should be addressed before publication.

 

Specific comments：

1. Fig 1 annotation: spelling error, greater.

2. Fig 1: What is whc?

3. Line 354: spelling error, Tables 7 and 8.

4. Fig4: The two figures in the bottom seem not match. In the right figure some buoy values are greater than 14, while the left figure does not contain those values. Please check it.

5. Fig5-12 are suggested to be placed near the corresponding content of the article.

6. In the whole manuscript, I suggest to modify k0Hs as k₀Hs.

7. In section 3.2, it seems that different radars adopt different Nonlinear correction parameters M, please give a discussion on it using several sentences. And the manuscript indicates that “This suggests M should be increased for waves coming towards and away from the radar and decreased for the perpendicular case.” Is it possible to automatically change M in the real-time process?

Comments on the Quality of English Language

1. Fig 1 annotation: spelling error, greater.

2. Fig 1: What is whc?

3. Line 354: spelling error, Tables 7 and 8.

4. Fig4: The two figures in the bottom seem not match. In the right figure some buoy values are greater than 14, while the left figure does not contain those values. Please check it.

Author Response

Please see note to editorial team for other details

1 Done
2 A note has been added to the caption in Fig 1 to clarify this.
3 Done
4 See li 297-300 in the revisions document. 15 seconds was chosen as the upper limit of the plot for clarity but values above this are included in the statistics.
5 I have changed my placement parameters so hopefully better alignment has been achieved.
6. k_0 has been modified throughout
7. I hope lines 351 to 361 in the revisions document make this clearer. When we implement the full nonlinear correction the impact will be modified during the inversion. This will be a better and more robust solution then trying to modify the approximation during the inversion particularly since directions measured with single radars are not so accurate.

Reviewer 2 Report

Comments and Suggestions for Authors

This paper introduces novel statistical methods to evaluate the accuracy and performance of wave measurements by HF radar. Through these statistical methods, the paper evaluates the accuracy of the SV method in measuring various wave parameters in HF radar systems and explores the performance differences between the single and dual HF radar systems. In addition, this paper also studies and analyzes methods for separating wind waves and swells in radar data. The proposed wave measurements and their statistical methods show commendable reliability and practical significance. Here are some suggestions for improving this paper:

1.The paper introduces some new statistical methods, such as WPI, etc., to evaluate the accuracy of wave measurements. Although the methods used in this paper have been evaluated, is it necessary to use these indicators to compare and evaluate the accuracy of the existing methods, such as the Barrick method?

2.Compared to the wind waves and swells separation method utilized in this paper, other methods such as the AIA method may have varying impacts on the overall accuracy assessment of wave measurements. Further comparison and explanation are necessary to evaluate this effect.

3.Most figures in the paper are are screenshots based on the software. Is it possible to replace them with exported vector images?

Author Response

Please see note to editorial team for other details

1 See li 509-510 in the revisions document where I have noted that we would want to encourage anyone making wave measurements to use the recommended methods and of course to be clear about the statistics used.
2.It wasn't our intention to directly compare AIA swell and wind sea estimates with ours. We do not have those data only figures from their paper. The AIA method makes many assumptions about spectral shape. Our approach is more akin to that used in wave modelling since we are measuring the directional spectrum rather than parameterising it. I think your comment should perhaps be addressed to the AIA authors. I agree that further quantitative validation of our approach would be useful but that will always be difficult since spectral partitioning can also be tricky for models, buoy and other wave data.
3. None of the figures are screenshots. All are png files and the original files are included in the package submitted to Remote Sensing. I have rescaled them where possible for clarity.

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript has been prepared correctly and carefully. It is a continuation and extension of research in the field of a validation of the SV wave inversion method. The reference analysis is extensive and exhaustive. All literature items are cited in the text of the manuscript in the correct order. Figures and tables are clear and correctly described. The conclusions are comprehensive.

I recommend this manuscript for publication in its current form

Author Response

Nothing required, thank you

Please see note to editorial team for other details

Reviewer 4 Report

Comments and Suggestions for Authors

The paper reviews the wave measurement capability, limitations, and differences between different radar types. It discusses methods to assess accuracy using phased array HF radar data obtained from the University of Plymouth WERA radars, demonstrating good accuracy in measuring various wave parameters and identifying swell and wind-sea components in the directional spectra.

Consider the following recommendations

1. It is important to adhere strictly to the format of the journal.

2. The paper mentions limitations in the inversion method and poorer quality radar data as factors contributing to differences between buoy and radar measurements. However, it does not provide a comprehensive analysis of these limitations or propose specific solutions to address them.

3. The format of the citations is incorrect, i.e. [1], [2], [3], [4], please use [1-4]

4. English writing throughout the document should be revised. 

Comments on the Quality of English Language

In some sections of the document the wording is difficult to understand, a review by a native speaker is recommended.

Author Response

Please see note to editorial team for other details

1. I'm afraid I don't really understand this one. The paper was written using the Remote Sensing latex template so should meet requirements.
2. See li 531-545 in the revisions document where we have added some extra discussion to address this point.
3. This has been sorted out,
4 and following comment. Both authors are native English speakers, have read and re-read the document several times and have no concerns about the language. So we are not sure how to address this. If this reviewer still has concerns perhaps he/she could be more specific.