Comparative Analysis of Digital Elevation Model Generation Methods Based on Sparse Modeling
Round 1
Reviewer 1 Report
The issues discussed in the paper presented are important from the theoretical point of view and also for applications in geodesy and geophysics. I have some questions and recommendations to rhe authors.
1) All the abbreviations should be clarified (OMP, for example).
2) I mean that a mathematical background is to be introduced when describing the deficiency of topographic data. There exist various kinds of relief: dissected , smooth and so on. The difference between the lowest and highest topography marks can influence the results of any regularization procedure to a great extent. Therefore, some numerical analysis is needed.
3) Clarify, please, the reason why the areas in the red frames in Fig. 6 were selected.
4) Describe, please, the results shown in Fig. 8 and 9 with some more details. These Figures need to be redrawn because of some kind of "fineness" : they are hard to recognize (or read).
5) Give, please, the crucial features of the compressed sensing modeling of the entire DEM in frequency area. I mean the following: the size of area, thw highest and the lowest frequencies in the range, the relative accuracy which can be achieved and so on.
6) Fig. 11 is scarely readable.
English Language is well enough.
Author Response
We would like to sincerely acknowledge the constructive comments and suggestions. We revised our manuscript according to the comments. The details of the revisions are shown in the attached file (the corresponding parts in the revised manuscript are highlighted in trackchanges.pdf).
Author Response File: 
Author Response.pdf
Reviewer 2 Report
General Comments：
This manuscript constructs multiple DEM generation methods by considering various types of sparsity in sparse modeling and performs a comparative analysis. Then, the applicability of each method is verified on actual data obtained from ALB measurements. Based on discussing the results and summarize the characteristics of each method, they developed a method integrating both the K-SVD and the TV minimization methods and confirm its effectiveness. The subject of the paper is interesting, with a great potential of application. However, I have listed 3 concerns as the followed detailed comments, which could be helpful for the improvement of the manuscript.
Detailed Comments:
（1）It was mentioned in Introduction that we also developed a method integrating both methods and confirm its effectiveness. I could only saw little bit of and description of this section at the end of the discussion section. It should be a key conclusion in this paper, suggesting that the author write more words to describe this conclusion or naming that method integrated both the K-SVD and the TV minimization methods with abbreviated word.
（2）In Section 4.1, the authors should introduce the basic information of the study area, such as location, topography and geomorphology, or label latitude and longitude in Figure 6.
（3）The colors labeled by the different methods in Figure 8 and Figure 9 should differ more significantly from each other. For example, I can't tell the difference between DCT and TV because they are all blue.
Author Response
We would like to sincerely acknowledge the constructive comments and suggestions. We revised our manuscript according to the comments. The details of the revisions are shown in the attached file (the corresponding parts in the revised manuscript are highlighted in trackchanges.pdf).
Author Response File: Author Response.pdf
Reviewer 3 Report
The manuscript entitled “Comparative Analysis of Digital Elevation Model Generation Methods Based on Sparse Modeling”, by T. Fuse & K. Imose, presents an interesting work.
In general, the manuscript should be acceptable for publication but some problems must be repaired prior to publication. Some suggestions are as follows:
- It would be useful to be described the aim of this paper.
- The abstract should state briefly the purpose of the research, the principal results and major conclusions. An abstract is often presented separately from the article, so it must be able to stand alone. Present conclusions.
- You could enrich the scientific literature. The literature is so poor.
- Please justify convincingly why this manuscript (method, thematology etc) connected with RemoteSensing’s content and scope. Perhaps the using of proper literature from this journal would be helpful.
- Please use coordinates in all maps (satellite images).
I have not any corrections to propose.
Author Response
We would like to sincerely acknowledge the constructive comments and suggestions. We revised our manuscript according to the comments. The details of the revisions are shown in the attached file (the corresponding parts in the revised manuscript are highlighted in trackchanges.pdf).
Author Response File: Author Response.pdf
