An Improved Propagation Prediction Method of Low-Frequency Skywave Fusing Fine Channel Parameters
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe following modifications need to be made before the paper is officially published:
1、In the paper, some places write ITU-R P.684, while some places write ITU. It is recommended that the author should use a unified description throughout the text.
2、There is no discussion section in the paper, it is suggested to add a discussion
section
3、In the paper, the author only used the Kriging interpolation method, and the improvement effect was not obvious. It is recommended to consider several interpolation methods and select the optimal one for model optimization after comparative analysis.
4、The conclusion section overlaps with the abstract section. It is recommended that the author carefully and thoroughly write the conclusion section of the paper.
5、Some figures in the paper have missing vertical and horizontal coordinate annotations (such as Figures 2 to 6, Figures 9 to 10,Figures 13 to 14 etc.).
6、There are many residual diagrams in the paper, but there is little statistical information on tables. It is recommended to add statistical information on tables.
7、Suggest checking the format of the reference paper to ensure consistency with the journal paper.
Comments on the Quality of English LanguageThere are no grammar issues with this article.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe main subject of this article is an attempt to improve the long term prediction of ionospheric data in relation to previous models . However, the results are not so encouraging. Some improvements of 6.81% and 3.69% (time and spatial domains respectively) as well as a 3.73% final improvement, mentioned in the conclusions paragraph they are not considered as satisfactory.
In the following, some specific comments on the article are enumerated:
1.- The introduction paragraph is too long.
A detailed historical review of the subject, since the beginning of the 20th century, overloads the article with details which they do not offer a particular supporting to the main subject.
2.-In the figure 4 it is not well understandable what various colors mean. Expressions like “..various colors show different classifications..” or “….figure 4 (c) uses squares of different colors to distinguish regions with varying levels of refinement .” do not help somebody to understand what the authors try to depict in this figure . All the section between the lines 273 and 284 needs revision in order to become more understandable.
3.-In the figure 7 dashed lines look like they have been drawn by free hard and not by a least-square method. There are points very far from the lines (t=4,5 and 21,22) which appear like they have been excluded from the lines drawing. Accuracy percentage of the predicted values in relation to the observed should be mentioned.
4.- In the figure 12 a great dispersion of the points is obvious after the no. 20 data points. It is difficult to differentiate and detect among observed, and predicted values with ITU and improved method. Authors should find a more explicit way to present their findings. Accuracy percentages of both the predicted values should be presented.
5.- An extensive discussion paragraph before the conclusions should be inserted. An overall criticism of their work giving emphasis in the way their work could help in areas they mentioned in the beginning of the abstract, should be necessary.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsA new method has been proposed by Wang et al to enhance the predictive precision of low frequency sky-wave propagation. The paper was organized well and results are reliable. I would suggest a minor revision before the paper being published in RS. Specific concerns are listed below:
1. The first paragraph can be divided into two paragraphs. It is too long to follow.
2. Limitations of the new method should be discussed in the manuscript.
3. There are so many receivers in Figure 9, are they calculated by simulation or real receivers?
4. Line 473: what the positive differences indicate? Between 0 and 5 dB.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsThe author has made individual revisions based on their own opinions and agrees with the current publication.
Comments on the Quality of English LanguageThere is no problem with the language of the paper.
Reviewer 2 Report
Comments and Suggestions for AuthorsThe article has been revised sufficiently.
