Evaluation of Unmanned Aerial Vehicles (UAV) as a Tool to Predict Biomass and Carbon of Tectona grandis in Silvopastoral Systems (SPS) in Costa Rica
Round 1
Reviewer 1 Report
Please find attatched detailed reeview.
Comments for author File: 
Comments.pdf
Author Response
Detailed review:
- References, should be numbered as they appears in the text – see instruction for authors.
Author answer: All references were presented according to instruction for authors
- Line 66 – “UAVS” – typically correct abbreviation of plural is “UAVs”
Author answer: the abbreviation was changed across the text.
- Figure 1 – descriptions are not readable in that scale
Author answer: The figure was modified, and the resolution was increased.
- Line 101 – sentence not understood. Please explain what is or who is Olman Murillo Gamboa.
What is GENFORES. Reference 32 is not in English. Or please modify this sentence to be clear.
Author answer: this sentence was modified according to this observation.
- Line 104 – add units to 2.5x1.0, etc.
Author answer: It was added units in the spacing across the text.
- Line 134 – add reference to the ASTM – published version
Author answer: It as added the reference
- Line 144 – add type, producer, country of this equipment
Author answer: It was added the information.
- Line 154 – equation should ends with comma and where in the next line is lower case. Like a
one sentence.
Author answer: It was modified this sentence.
- Equations – in some equations you give units in brackets, in some not. Please unify, and
provide units to all equations, if needed.
Author answer: It was added the units in all equation.
- Line 173 – pix4d mapper – add producer, country and version as you did it above.
Author answer: It was added the information
- Table 1- Layout design – please explain or provide reference to 3D layout. 3D is a double grid
?
Author answer: It was added the information
- Line 192, 227 – style: comma like in previous comment (8)
Author answer: It was corrected these lines
- Table 3 and 3a – the same caption but different values inside, values in “()” not understand –
do information found what are these values), what is “a” after the values”. Please explain in the text. I understand that the columns values are in the different unit in table 3a, with respect to the table 3. I would recommend to give a next number to this table (4)
Author answer: It was modified the location and information about letters and values in parenthesis.
- Table 4 – add references in [] to columns
Author answer: it was added the references in all columns
- Table 6 – VANT not defined
Author answer: It was changed VANT by UAVs
- The flight at this height to this task is to high. I would recommend do go at 30-40 meters to
have better 3D data.
Author answer: The authors disagree with this observation. According to objective, we proposed UAV-generated orthomosaic for different parameters and 3D data was not explored. Then according to results with orthomosaic model, the flight tests recommended was less than 100 m height, which includes 30-40 meters
- Drone and photogrammetric part of the study is omitted. Please add analysis of reports,
visualisations.
Author answer: The part was presented in section 3.6 Selection of the orthomosaic
- Why you calculated volumes from orthophotos. It seems reasonable to calculate it from 3d
model of the field and tree. If the flight was on the 30 meters, you could calculate volume of the tree from the 3D model.
Author answer: the observation 16 was discussed this situation. The volume was not calculated using proposed 3D model. UAV-generated orthomosaic was used for calculating the crown diameter and the height of the trees. Then the crown diameter was put into the dbh prediction model to obtain the dbh of the trees. And finally, the variables, dbh and tree height were used in selected biomass equation. Then for this reason, the calculations were made using UAV-generated orthomosaic. Besides, the calculation was done this way because the author wanted to show that this is a feasible way of doing this calculation than 3D model.
- Generally manuscript is very interesting. The research is very good and important to the Word. I strongly recommend to add more details as for the photogrammetric and drone part of the research. In conclusions you stated that the calculations form the orthophotos was difficult. I think that there were some problems with the photogrammetric part of the research, that is why is you had problems with calculations. There is no detail about calculations did form drone measurements, it should be added.
Author answer: The authors thanks this commends, and 3D model was discussed in the observations 16 and observations 18.
Reviewer 2 Report
The purpose of this research was to evaluate the use of Unmaned Aerial Vehicles in estimating above ground biomass and carbon, and the dasometric characteristics at three different spacings in a Silvopastoral System (SPS) for biomass production of Tectona grandis. However, before it was published in this journal, some parts in the paper should be revised and polished.
- In the line 69-70, authors of the references should be presented in the text, but not a number.
- In the part of Materials and Methods, there are too many sub-sections which reached to 13. In fact, 4-5 sub-sections were proper which followed by Study area, Data, Methods….
- For the Figure 1, Legend and scale should be added, and the right figure was too small, I can't see the details.
- In the Results, e.g. 3.1, the clear description of the results from the analysis should be written first, previous researches which prove your results should in the last in this sub-section.
Comments for author File: 
Comments.docx
Author Response
Review 2
- In the line 69-70, authors of the references should be presented in the text, but not a number.
Author answers: According with author instructions the references were be written in number
- In the part of Materials and Methods, there are too many sub-sections which reached to 13. In fact, 4-5 sub-sections were proper which followed by Study area, Data, Methods….
Author answer: The authors thanks this observation. The sections were shorted to 7.
- For the Figure 1, Legend and scale should be added, and the right figure was too small, I can't see the details.
Author answer: The authors thanks this observation, The figure 1 was improvement.
- In the Results, e.g. 3.1, the clear description of the results from the analysis should be written first, previous researches which prove your results should in the last in this sub-section.
Author answer: The authors thanks this observation, the last lies were relocated in being of first paragraph.
Author Response File: Author Response.docx
Reviewer 3 Report
I am not native speaker but I am no sure that "aboveground" is written properly.
Line 44: Replace "people" by "stakeholder"
Introduction should be improved. There are no references link to active and passive sensor like RGB, multispectral, radar or LiDAR. On the other hand, you should take into account and describe different approximations by satellite, manned and unmanned aerial platforms. In addition, you should indicate a comparative between traditional and technological methodologies.
Line 90: Please, indicate coordinate reference system and replace "North" and "West" by N and W.
What is the are covered in your study?
I recommend to replace "trial" by a more formal term.
Figure 1. It is quite difficult to read texts.
Table 1. Replace "Ground surface distance" by "Ground Sample Distance". What do you mena with "layout design"?
Please , add information about the camera: focal length, image size, sensor size...
Section 3.3: What test have you used to know there are not statistical differences?
Figure 3. You should provide information about the residuals of your adjustments. For example, did they follow a normal distribution?, what about Cook's distance?...
Please, write about the difficulties of UASs in this applications. Do you think that you can covered large areas.
Author Response
Review 3
- I am not native speaker but I am no sure that "aboveground" is written properl
Author answer: The article was edited for English language by MDPI
- Line 44: Replace "people" by "stakeholder"
Author answer: it was changed.
- Introduction should be improved. There are no references link to active and passive sensor like RGB, multispectral, radar or LiDAR. On the other hand, you should take into account and describe different approximations by satellite, manned and unmanned aerial platforms. In addition, you should indicate a comparative between traditional and technological methodologies.
Author answer: this observation was considered. L61-L67
- Line 90: Please, indicate coordinate reference system and replace "North" and "West" by N and W.
Author answer: it was changed.
- What is the are covered in your study?
Author answer: it was detailed this observation L118-L127
- I recommend to replace "trial" by a more formal term.
Author answer: The authors thanks this observation, trial work was changed by “spacing test”
- Figure 1. It is quite difficult to read texts.
Author answer: The authors thanks this observation, The figure 1 was improvement.
- Table 1. Replace "Ground surface distance" by "Ground Sample Distance". What do you mena with "layout design"?
Author answer: This observation was considered and clarified in the table.
- Please , add information about the camera: focal length, image size, sensor size...
Author answer: The information was added.
- Section 3.3: What test have you used to know there are not statistical differences?
Author answer: The information was added and clarified
- Figure 3. You should provide information about the residuals of your adjustments. For example, did they follow a normal distribution?, what about Cook's distance?
Author answer: The information was added L345-246
- Please, write about the difficulties of UASs in this applications. Do you think that you can covered large areas.
Author answer: The recommendation and implications were indicated in the conclusion.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
The article has been rewieved as sugested.
Thank you.
Reviewer 2 Report
The authors improved the manuscript followed my suggestion, I agreed to publish this paper in this journal.
Reviewer 3 Report
Authors have taken into account my suggestions. Manuscript is adequate to be published.
