A Strategic Framework for Establishing Additional In Situ Data Acquisition Sites for Satellite Data Calibration and Validation: A Case Study in South Korean Forests

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

I found the paper to be a novel and interesting approach to assessment of cal/val sites for a limited area for a specific application.

I was able to follow the description in the analysis of how the various distances and the forest site composition dissimilarity was determined, and how they were combined to provide a combined heterogeneity index. However, a deep investigation into those processes would be required to evaluate the suitability of the approach. In particular, is it appropriate to combine them as described or is it possible that the various scales are inappropriately weighted.  Perhaps further information on this matter would be of benifit to the reader.

Please see the following comments for the identified line number.

116 – 117            “built by Korea Forest Service [23]”.  This information was already provided in line 109-110.

130         “2.1.2. Analyze” - should be “2.1.2. Analyses”

135         Cli-mate --> Climate

136         ex-amine --> examine

137         cate-gory --> category

154         What does ‘FD’ refer to?

209 – 210              “, so it is considered to be installed in ….”  Not sure what this refers to. Is it ‘so new sites located in the center, south, and east are to be of prime consideration.”

214 – 215             The green part of the map is the study area (grid with …. à The green area of the map is the forested study area (grids with ….

221-222                   “…℃, with the lowest temperatures between 10.3 ℃ and 11.0 ℃” – I am not following this statement nor the similar one in 223 – 224

247                         ‘other’ is not adequately descriptive. Perhaps ‘complete South Korean forest grid’.

310                        How do the 5 climate variables get combined to provide a similar distance of climate?

311                         ‘increase from the peninsula to the south’. The entire region is a peninsula. Perhaps ‘increase from the base of peninsula to the south’ would be more appropriate.

311                         Where is Jiri Mountain? It is not mentioned elsewhere.

338                         Why is determining the minimum combined normalized heterogeneity index and normalized period a suitable approach for identifying the optimal number of installations?

517- 518                “In conclusion, a total of 33 Cal/Val sites are considered necessary for South Korea, in addition to the 8 existing sites.”. Shouldn’t this read 25 in addition to the existing 8 for a total of 33?

Comments on the Quality of English Language

The English was found to be clear and concise.  There are a couple of clarifications that are noted in the general comments.

Author Response

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted in the re-submitted files.

 

Comments 1: [116-117] “built by Korea Forest Service [23]”.  This information was already provided in line 109-110.

Response 1: The redundant information you mentioned has been removed (refer to line 131).

 

Comments 2: [130] “2.1.2. Analyze” - should be “2.1.2. Analyses”

Response 2: Adjustments have been made (refer to line 144).

 

Comments 3: [135] Cli-mate --> Climate

Response 3: Revisions have been made, and similar errors have been examined across the document (refer to line 149).

 

Comments 4: [136] ex-amine --> examine

Response 4: Revisions have been made, and similar errors have been examined across the document (refer to line 150).

 

Comments 5: [137] cate-gory --> category

Response 5: Revisions have been made, and similar errors have been examined across the document (refer to line 151).

 

Comments 6: [154] What does ‘FD’ refer to?

Response 6: We have added the full name of the abbreviation FD along with a brief description of the FD package (refer to lines 178-181).

 

Comments 7: [209-210] “, so it is considered to be installed in ….”  Not sure what this refers to. Is it ‘so new sites located in the center, south, and east are to be of prime consideration.

Response 7: Our intent was to indicate the necessity of establishing additional sites in the southern and eastern regions, as the current Cal/Val sites are only located in the northern and western areas. We have clarified this intention in the text (refer to lines 252-255).

 

Comments 8: [214-215] The green part of the map is the study area (grid with …. à The green area of the map is the forested study area (grids with ….

Response 8: We have revised this section as suggested to clarify the meaning (refer to lines 258-260).

 

Comments 9: [221-222] “…℃, with the lowest temperatures between 10.3 ℃ and 11.0 ℃” – I am not following this statement nor the similar one in 223 – 224

Response 9: The original intention was to refer to the range of the most frequently occurring values in the histogram, which was incorrectly stated. This section has been accurately revised, and We have checked for similar errors in the interpretation of other histograms (refer to lines 264-268).

 

Comments 10: [247] ‘other’ is not adequately descriptive. Perhaps ‘complete South Korean forest grid’.

Response 10: Yes, you are correct. We have modified the figure title to ensure clarity, along with other figure titles (refer to lines 291-292, 305-306, 330-331, 347-348).

 

Comments 11: [310] How do the 5 climate variables get combined to provide a similar distance of climate?

Response 11: The methodology was not clear in the original draft. We have elaborated on the entire methodology, including the calculation of the heterogeneity index (refer to lines 153-194).

 

Comments 12: [311] ‘increase from the peninsula to the south’. The entire region is a peninsula. Perhaps ‘increase from the base of peninsula to the south’ would be more appropriate.

Response 12: We have revised this section to clarify its meaning as you suggested (refer to lines 355-358).

 

Comments 13: [311] Where is Jiri Mountain? It is not mentioned elsewhere.

Response 13: The latitudes and longitudes of all locations have been included (refer to lines 355-358).

 

Comments 14: [338] Why is determining the minimum combined normalized heterogeneity index and normalized period a suitable approach for identifying the optimal number of installations?

Response 14: While this content was already discussed in the discussion section, it lacked clarity in the methodology. Therefore, We have maintained brevity in the results section while adding a description of this content in the methods section (refer to lines 199-213).

 

Comments 15: [517-518] “In conclusion, a total of 33 Cal/Val sites are considered necessary for South Korea, in addition to the 8 existing sites.”. Shouldn’t this read 25 in addition to the existing 8 for a total of 33?

Response 15: That is correct. We have revised the description accordingly (refer to lines 568-570).

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Dear authors and editor,

 

The paper entitled [A Strategic Framework for Establishing Additional In-Situ Data Acquisition Sites for Satellite Data Calibration and Validation: A Case Study in South Korean Forests] proposes a framework that includes a methodology for assessing representativeness, a process for determining the number and location of additional installations, and a method for evaluating existing ground observation networks. The topic of this study is interesting and holds application value for the calibration and validation of satellite data. However, there are some issues that need to be addressed before publication:

 

（1）The abstract needs improvement. It should provide a concise description to the research methods, such as how the "framework" was constructed and how the ground observation data was processed. Additionally, the heterogeneity index is an interesting point and should ideally be explained to some extent.

（2）In the introduction (Lines 67-72), the innovation of the study and the scientific issues it addresses need to be emphasized.

（3）In Lines 88-97, the purpose of the study is to determine the optimal number of sites, and your results also provide the optimal locations for these sites. Please verify this information.

（4）In the Materials and Methods section, I recommend including a flowchart to aid in understanding the evaluation framework you have constructed.

（5）In the Materials and Methods section, your analysis process is difficult to understand. I suggest adding some necessary equations. Specifically, I am unclear about how the heterogeneity index is calculated and utilized.

（6）Figure 8 needs improvement. It is recommended to include explanations of the Cal/Val site within the figure.

Author Response

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted in the re-submitted files.

 

Comments 1: The abstract needs improvement. It should provide a concise description to the research methods, such as how the "framework" was constructed and how the ground observation data was processed. Additionally, the heterogeneity index is an interesting point and should ideally be explained to some extent.

Response 1: We have emphasized the novelty and intriguing aspects of the heterogeneity index and framework of this study and rewritten that section (refer to lines 9-32).

 

Comments 2: In the introduction (Lines 67-72), the innovation of the study and the scientific issues it addresses need to be emphasized.

Response 2: We have highlighted the points you mentioned and ensured a smooth transition to the subsequent paragraph (refer to lines 83-86).

 

Comments 3: In Lines 88-97, the purpose of the study is to determine the optimal number of sites, and your results also provide the optimal locations for these sites. Please verify this information.

Response 3: Indeed, We were able to further emphasize the innovation of the research by adding this description. Thank you (refer to lines 105-106, 111-112).

 

Comments 4: In the Materials and Methods section, I recommend including a flowchart to aid in understanding the evaluation framework you have constructed.

Response 4: We have made the descriptions in the materials and methods section clear and detailed, while generalizing the overall framework of this study in the discussion section (refer to Figure 14).

 

Comments 5: In the Materials and Methods section, your analysis process is difficult to understand. I suggest adding some necessary equations. Specifically, I am unclear about how the heterogeneity index is calculated and utilized.

Response 5: The descriptions in the materials and methods have been clarified throughout (refer to lines 153-194).

 

Comments 6: Figure 8 needs improvement. It is recommended to include explanations of the Cal/Val site within the figure.

Response 6: A legend has been added to clarify the meaning of each point (refer to Figure 8).

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

My issues have all been resolved, and I have no more comments.