Application of Unmanned Aerial Vehicle and Airborne Light Detection and Ranging Technologies to Identifying Terrain Obstacles and Designing Access Solutions for the Interior Parts of Forest Stands
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsDear authors,
Thank you for interesting manuscript. I personally found it useful. However, there are small room to improve.
- Please use the full term with the abbreviation in parentheses when first mentioned, and thereafter, use only the abbreviation throughout the rest of the paper.
- What method did you apply for planning timber extraction?
- Please add labels to the map in Figure 2
- The results section effectively demonstrates the superior accuracy of UAV and ULS technologies in detecting terrain obstacles, but it lacks statistical validation to substantiate these findings.
-In Figure 4, I suggest revising the color scheme for better clarity:
- Height of obstacle 0.0–0.5 m: Dark green
- 0.5–1.0 m: Light green
- 1.0–2.0 m: Yellow
- 2.0–5.0 m: Orange
- More than 5.0 m: Red.
-In Figure 6, I have concerns that the feature labeled as a "Forest Road" might be incorrect; it appears more likely to be a water body. Please verify and provide clarification.
- The term "timber stacks" should be replaced with "landing."
- Figure 7 and the content in lines 331–336 should be removed, as they appear irrelevant. Additionally, the area depicted seems different from the study site. Please confirm and clarify if my observation is incorrect.
- Line 343 appears to be incomplete, with missing content before the citation {43}
- Can authors specify the optimal area size suitable for each method, such as ULS, UAV, ALS, etc?
Author Response
Dear reviewer, all comments are included in the appendix
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe study mainly focuses on the application of Unmanned Aerial Vehicles (UAV) and Airborne Laser Scanning (ALS) technologies to identify topographic obstacles during forest harvesting, and to plan accessibility schemes to the interior of the stand using skidder trails. By comparing and analyzing the accuracy of the digital terrain model (DTM) created by UAV LiDAR, UAV RGB, ALS data and publicly available LiDAR data (DMR 5G), the effectiveness of different remote sensing methods in identifying terrain obstacles and planning skidding trails was evaluated. After carefully reviewing the manuscript, my suggestions for revision are as follows:
1. There are too many keywords; it is recommended to reduce them.
2. It is recommended to include accuracy performance metrics in abstract.
3. It is suggested to add a satellite image to Figure 1. Additionally, all figures in the manuscript should include key information such as coordinates.
4. In the introduction, a lot of work is sorted out, but the advantages and advancements of this study compared with these existing works are not clearly explained, and there is a lack of clear comparison and explanation.
5. Some of the figures in the manuscript have the problem of incomplete information annotation. For example, in Figure 4 and Figure 5, the meaning of the coordinate axis and the details of the legend are not clearly marked, which affects the reader's understanding of the content of the chart, so it is recommended to optimize the figures.
6. The outlier handling method in the process of data processing is not explained in the manuscript. Given that outliers can affect the accuracy of the study results, it is recommended to supplement this section.
7. When determining the planning of skidding trails, only the factors such as terrain slope, obstacles and distance were considered, and the restrictions of forest ecological environment on planning were not fully considered. It is recommended to increase the assessment and discussion of ecological impacts to make the results of the study more feasible.
8. In the evaluation of DTM accuracy, the height deviation between DTMs generated by different data sources and the ability to detect terrain obstacles are compared, but different terrain conditions may have a significant impact on data acquisition and model accuracy, and it is recommended to further explore them.
9. The advantages and limitations of UAV and ALS technologies are mentioned in the discussion part, but there is a lack of specific guidance and suggestions on how to reasonably select and combine these two technologies according to different scenarios in actual forestry operations, and it is recommended to further refine them.
10. Although the application effect of UAV and ALS technology in forestry is summarized in the conclusion, considering the continuous development of technology and the change of forestry operation needs, it is suggested that the shortcomings of this study and the direction of future research should be pointed out in the conclusion.
11. It is suggested to add uncertainty analysis to discuss its impact on the research results and increase the reliability of the study. For example, the uncertainty of the data itself or the accumulation of errors.
Comments on the Quality of English LanguageThe English language expression in the manuscript can be checked and improved.
Author Response
Dear Reviewer, All comments are included in the appendix
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Comments and Suggestions for Authors1) The "m" symbol located at the lower right side of Table 3 requires verification of its correct placement.
2) It is recommended to add coordinate information to Figure 1 accordingly.
3) Additionally, a north arrow should be incorporated into Figure 2.
Author Response
Dear reviewer, thank you very much for your effort and valuable comments. We corrected figures based on your comments.
Best regards Tomas Mikita.
