Assessing the Potential of Onboard LiDAR-Based Application to Detect the Quality of Tree Stems in Cut-to-Length (CTL) Harvesting Operations
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsVery interesting paper!
I recommend that you explain in a little more detail what other studies have achieved in The State of the Art section, not just write that the results are promising.
However, the challenge of harvesting on steep terrain (typical of the mountainous regions of Europe) remains, as the vertical field of view will change frequently.
Author Response
Hello,
Please see the attachment.
Br,
Anwar Sagar
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe authors studied the potential of LiDAR systems in assisting harvester operators, aiming to mitigate workload, reduce decision errors, and optimize the harvesting workflow. They used both synthetic and real-world 3D point cloud data sets for tree stem defect analysis, and developed two processes for tree stem and defect identification based on LiDAR technology and analyzed the challenges and advantages. The testing of the processes gave promising results and pointed directions for further development. I think the manuscript was well written and had novelty. It can be accepted for publication after minor revision. The following issues can be taken into consideration for improvement.
1. In the abstract, two sets of numbers (0.00229 & 0.772% and 0.000767 & 1.394%) between lines 22 and 23 are mutually contradictory. That is, 0.000767 is less than 0.99229, but 1.394% is greater than 0.772%. Additionally, I can’t find 0.00229 in the text elsewhere.
2. Line 232: generation can be removed. Line 267: “1024, it.” It is wrong?
3. Line 340-346: I think these paragraphs and Figures can be removed, because the following text has described the process clearly.
4. Line 397: Equation (8) is better to remove after equation (7).
5. Line 424-426: RMSE values need to have a unit (m?), and RMSE% values are accurate enough to preserve two decimal digits, such as 0.77% and -0.59%. Same to the values in the whole text and the abstract.
6. Fig.9: The small green points are not bright enough, which need to be so bright as the Fig.8.
7. Line 456-462: There is a little bit regret, because the accuracy assessment is only based on three measured values. If it is based on more than 10 even 30 measured values, it would be fine. I suggest point out this limitation in the discussion.
Author Response
Hello,
Please see the attachment.
Br,
Anwar Sagar
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsFind my comments in the pdf file. It is an interesting paper, methodology and statistics are fine. However, I have some minor comments/suggestions to improve the overall status of the paper.
Comments for author File: Comments.pdf
Author Response
Hello,
Please see the attachment.
Br,
Anwar Sagar
Author Response File: Author Response.pdf
Reviewer 4 Report
Comments and Suggestions for AuthorsAssessing the potential of onboard LiDAR-based application to detect the quality of tree stems in cut-to-length (CTL) harvesting operations
Sagar et al.
General comments:
The authors present a novel study that investigates the integration of LiDAR technology in cut-to-length (CTL) harvesting machines to enhance tree selection accuracy and efficiency.
However, the structure of the work does not adapt to that of a scientific document and has serious flaws. Furthermore, the results obtained are insufficient for the article to be publishable in a high-impact JCR journal.
Specific comments:
- Introduction
Delete lines 68-71
Includes the chapter: "2. The state of the Art" in the introduction and reduces the whole a bit.
Chapter "2.2 The defects of the tree stem". This should not go in the introduction. Perhaps in Materials and Methods or as part of the Discussion.
-Material and Methods.
Includes chapter: "3. Mobile LiDAR in Forest Scanning" and its headings in Materials and Methods.
Delete lines 231-233.
In the chapter "Determining the accuracy" please also include the mean absolute error (MAE) and (MAE%), this will improve the results obtained.
- Discussion and conclusions. Make these two chapters separate. Improve the discussion by discussing with other works in the same field.
Improve the conclusions.
Author Response
Hello,
Please see the attachment.
Br,
Anwar Sagar
Author Response File: Author Response.pdf
Reviewer 5 Report
Comments and Suggestions for AuthorsI must preface this review and state that I am not an expert in LiDAR associated technology. The paper is quite dense with terms and processes that are inaccessible to a general forestry audience.
The paper is well written and comprehensive. The paper contributes to our knowledge of how this technology can improve efficiency in mechanized harvesting operations using cut-to-length systems. The authors claim it can improve sustainability, but do not provide evidence to support this premise.
P2L47 – Clarify what you mean by manual bucking. It is my understanding and experience that a harvester/processor bucks in the forest with an optimizer that considers optimal length and product.
P2L56 – So you are advocating for the removal of the forester’s role in selecting stems to leave or cut. This will be replaced with MLS. Perhaps a caveat should be made that this may work in conifer plantations, but not in natural stands – particularly hardwoods.
P3L127 – Need to justify how this technology aligns with sustainability goals. When working properly, it can be more efficient, but not sure how that links to sustainability.
P4L149 – Please define crook and curve more thoroughly. In my region, a crook in a stem represents a segment that is not merchantable. A curve, on the other hand, is more gradual, and with skilled bucking to shorter lengths, can allow for merchantability.
P4L151 – Since 1cm is equal to 10 mm, why did you not maintain the same units (cm).
P6L231 – change “chapter” to “section”
P6L236 – It is not clear what is meant by “manual generation” of data.
P6L243 – Is synthetic data associated with manual generation of data?
P7L260 – It is not clear if the “real-world” data was actually collected in the real world. The authors refer to a forest in Finland, but do not provide details on forest area and number of stems included in the study. What is the sample size (N)?
P8L293 – Figure 5 suggests that the point cloud data collected from the MLS on the harvester was ground-truthed with field measurements. How many stems were actually verified via field measurements? Isn’t this the basis for testing the effectiveness of the MLS in selecting crooked and curved stems versus using the expertise of the machine operator? This is not clearly explained.
Figures 4 and 10 are difficult to discern due to poor resolution.
P13L465 – How can MLS on harvesters improve the tree selection process when you only looked at two variables – crook and curve? There are many other variables that contribute to Acceptable vs. Unacceptable growing stock. The MLS might be able to make the process more efficient, but not necessarily more effective. The most effective manner is to have a forester making those decisions on the ground. This is clearly not as efficient as scanning a tree with LiDAR.
P14L485 – Please explain to the practitioner forester how synthetic data facilitates testing of MLS in real forestry harvesting. Assume that most readers could not follow your methods.
P14L494 – Sustainability is a nice buzz word that makes people feel good, but please justify how MLS technology improves sustainability. If poorly implemented, MLS technology could actually detract from sustainability objectives.
Comments on the Quality of English Language
The writing is acceptable.
Author Response
Hello,
Please see the attachment.
Br,
Anwar Sagar
Author Response File: Author Response.pdf
Round 2
Reviewer 4 Report
Comments and Suggestions for AuthorsThe authors have considerably improved the article, so I now believe it is ready for publication.
Reviewer 5 Report
Comments and Suggestions for AuthorsI am satisfied with the authors' responses to my questions and concerns.
Comments on the Quality of English LanguageAcceptable
