Accuracy Evaluation and Branch Detection Method of 3D Modeling Using Backpack 3D Lidar SLAM and UAV-SfM for Peach Trees during the Pruning Period in Winter

Round 1

Reviewer 1 Report

(page 1/2)

 

This article presents an investigation based on the evaluation of different methodologies for 3D modeling of deciduous fruit trees (LeGO LOAM SLAM and UAV-SfM) to build models of pruning branches and the structure of main branches of peach trees of pruning period in winter.

In my opinion, I consider it a work of interest and it presents interesting findings to obtain 3D models of the pruning branches with an improvement in the computational cost (LeGO LOAM SLAM) compared to other methodologies (UAV-SfM).

However, keep in mind that there is a large bibliography where the advantages of using UAV-SfM in precision agriculture and also, compared to methodologies based on LiDAR data, are evident. If you deem it appropriate, it could be interesting to complete the bibliography of the work citing the advantages found in the following works.

https://www.mdpi.com/2072-4292/13/21/4387 (2021)

https://www.mdpi.com/2073-4395/11/12/2489 (2021)

https://www.mdpi.com/1999-4907/11/2/223 (2020)

https://www.sciencedirect.com/science/article/abs/pii/S0168169918314285?via%3Dihub (2019)

https://ieeexplore.ieee.org/document/8360738 (2018) 

 

I appreciate that the detection of pruning branches using SfM has its difficulties as shown in your research, but the photogrammetric technique can be very useful to relate the weight of the pruning branch with biomass and has certain advantages.

I consider an article of interest to the scientific community and suitable for publication in Remote Sensing.

When reading the article, I have noticed certain errors in some citations, the lack of reference in the text of figure 5 and some wrong dates. Next, I indicate these faults and some suggestions:

 

·         Line 23: change R2 for R²

·         Line 31: change ha, for ha.

·         Line 74: Add the reference Thrun et al. [15]

·         Line 76: change [15] for [16]

·         Line 84: Add the reference Shan et al. [19] and delete the line 87.

·         Line 93: delete (2021).

 

 

 

(page 2/2)

 

·     Line 107 to 109: Review some of these assumptions with the suggested bibliography. “On the other hand, there is not enough discussion on whether the Lidar method is better than the UAV-SfM method, which has been used widely in recent years concerning modelling, detection accuracy, and computation time”.

·         Line 147: Add the reference Shan et al. [?].

·         Line 272: Add the reference Hosoi & Omasa [35] and delete (2006).

·       Line 301 to 303: Review some of these assumptions with the suggested bibliography. “Moreover, aerial photography is affected by weather changes, and conditions such as strong wind or cloudy weather make it difficult to take pictures and obtain data smoothly”.

·       Lines 352, 426 and 435: change 24th December 2022 for 24^th December 2021.

·        Figure 4: Indicate the methodology used in the photo caption.

·    Figure 5: I could not locate the reference in the text, please include it. Indicate the methodology used in the photo caption.

·       Line 561: Add the reference Huang [20] (2021) and Xu et al. [39] (2022) and delete [20, 38] in line 563.

·        Line 576: Add the reference Nguyen [40] (2015), Paulus [41] (2019) and Kochi et al. [42] (2021) and delete in line 580 [40–42].

Author Response

Dear Reviewer:

Thank you for your kind comments and suggestions.
We have modified the article according to your comments.
The revised content is attached. Please see the attachment.

Sincerely,
Poching Teng

 

Author Response File: Author Response.pdf

Reviewer 2 Report

-Title, Keywords, and elsewhere, such as your objectives (Line 111) - "3D Lidar" - It is already widely known that when you say "lidar" you mean 3D. So the term "3D Lidar" is redundant and not useful. Just say "lidar", as a word, like sonar or radar.
-To follow up on the previous point, it's not clear from the Title or Abstract what your lidar platform is. You mentioned "fixed lidar", and from that my assumption that you're referring to ground-based lidar or terrestrial laser scanning (TLS)? If so, specify and use more commonly used terms. The term terrestrial laser scanning (TLS) has been in widespread use to refer to ground-based lidar for over a decade now.
-Also, the word is just "lidar", not "Lidar".
-Line 31 - "The whole area increased to a small..." - I'm not quite sure what you mean by this sentence. Clarify and specify more what you mean.
-Lines 58 to 73 - You mention lidar briefly (athough you don't mention anything about the lidar platform) but this paragraph focuses on UAV SfM. You only really provide one specific example of a UAV SfM study. I know there have been tons of UAV SfM studies on the topics of modeling tree parameters and precision agriculture, you should include more specific examples and details relevant to your project topic, not just one.
-Lines 74 to 93 - You introduce this SLAM method as an improvement on (I assume) traditional ground-based lidar or TLS, but this is not really clear. You need to do better introducing TLS before jumping into SLAM. I know there have been a ton of studies on the topic of ground-based lidar or TLS for measuring tree properties or precision agriculture, you should reference and discuss some of that here. This technology has been around for over a decade, so you should show some awareness of this with your literature review:
https://www.ingentaconnect.com/content/asprs/pers/2006/00000072/00000012/art00002
-Line 111 - "3D Lidar" - See previous comment. Make sure you correct this and use a better term throughout the paper. I would suggest ground-based lidar or backpack lidar or TLS, whichever term you feel is most appropriate, based on a proper review of the literature to use the term most commonly used.
-Line 115 - "On the other hand, the spatial density of the point cloud is proposed as the..." - I'm not sure what you mean by this last sentence of this paragraph. Clarify and specify better what you mean. On the other hand of what?
-Figure 1 - This figure is way too busy. Perhaps break up? One figure for A. One figure for B and C. And I have no idea what D is about? It's not properly explained in the caption.
-Line 155 - What wavelenth exactly? I assume NIR? Specify.
-Line 224 - "cloud compare software" - You need to more properly refer to and cite the CloudCompare software, this is a proper name.
http://www.cloudcompare.org/
-Lines 306 to 322 - Is all of this data what you show in Table 1? If so, you should refer to that table in the text.
-Figure 2 - This figure is comparing the point clouds from ground-based lidar and UAV SfM, correct? Why is the symbology between the two so different? It makes it difficult to compare.
-Lines 401 to 433 - This paragraph is too long, you should break it up into separate topics. It's also not clear what figure you refer to in this paragraph as "this figure" (Lines 424 to 426)?
-Figures 4 and 5 - Make sure you properly refer to these figures in the text.

Author Response

Dear Reviewer:

Thank you for your kind comments and suggestions.
We have modified the article according to your comments.
The revised content is attached. Please see the attachment.

Sincerely,
Poching Teng

Author Response File: Author Response.pdf