LiDAR-Based Hatch Localization
Round 1
Reviewer 1 Report
The document needs to be revisited by the authors in order to provide more readability. More connection with the state of the art and to better focus on showing where the results can improve the knowledge, and what are the connection that the work can have. At present, major revisions are needed.
When mentioning camera sensors, please be aware and also mention that sound signals are being used too for doing the task mention. This is quite a new argument deserving attention and still under developments, but some paper have been recent published and I suggest the authors to mention them: Bocanegra, Johan Augusto, et al. "A novel approach to port noise characterization using an acoustic camera." Science of The Total Environment 808 (2022): 151903.; Bocanegra, Johan A., Davide Borelli, and Corrado Schenone. "Measurements of ship noise using an acoustic camera: A first survey." The Journal of the Acoustical Society of America 150.4 (2021): A100-A100.; Fredianelli, Luca, et al. "Source characterization guidelines for noise mapping of port areas." Heliyon 8.3 (2022): e09021.
Avoid sub chapters or paragraph in the introduction. If it is too long, evaluate to create a new chapter 2 with “background” information needed for the understanding of the paper and for better connecting the present work to the scientific literature. Especially this last part woul improve the paper readability.
At the same time, please provide more information about lidars.
Methodology and results are fine, but discussions and conclusions are poor and need to be enriched.
If appendix A is presented for reviewer, I intend that the authors believe it is important to reviewers to better understand the work. So, why readers would be different from reviewers? Consider to add it to the main text.
Author Response
Thanks for the review work and valuable comments. Please see the attachment for our response.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
This work is interesting, and it is worth of being publicated.
Author Response
Thank you for the review work.
Reviewer 3 Report
References need an update, there are no references in 2022 through hundreds of papers on the same topic were published in 2022 as follows:
Tarsha Kurdi, F.; Gharineiat, Z.; Campbell, G.; Awrangjeb, M.; Dey, E.K. Automatic filtering of LiDAR building point cloud in case of trees associated to building roof, Remote Sens. 2022, 14, 430, https://doi.org/10.3390/rs14020430.
De Geyter, S.; Bassier, M.; Vergauwen, M. Automated training data creation for semantic segmentation of 3D point clouds. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLVI-5/W1-2022, 59–67, 2022, https://doi.org/10.5194/isprs-archives-XLVI-5-W1-2022-59-2022.
Wei, H.; Xu, E.; Zhang, J.; Meng, Y.; Wei, J.; Dong, Z.; Li, Z. BushNet: Effective semantic segmentation of bush in large-scale point clouds. Computers and Electronics in Agriculture, vol 193, 2022, 106653, https://doi.org/10.1016/j.compag.2021.106653.
The abstract does not need an introduction. Please focus on explaining the suggested approach and the result accuracy estimation. Please re-write the abstract.
Introduction
Line 18: “few articles”, it is unacceptable to say few articles because you didn’t scan all published papers in the world. Please cancel the word “few”.
The abbreviation [Light Detection and Ranging (Lidar)] must be “Light Detection And Ranging (LiDAR)], please check all abbreviations in the paper.
Lines 122 to 130 contribution
Please re-write the contribution because what you described is not a contribution, it is the advantages of the suggested algorithm. The contribution depicts the new ideas that you added that help solves a given issue or obtain excellent results.
Please add a photo of the used scanner
The data acquisition section needs a figure that mentions the described geometric parameters.
3.1. Objective and Notation
You said: “The objective of this paper is to process the unorganized point cloud PS to determine the P-frame hatch edges for each cycle.”
This sentence is vague because the term “process” is unclear, and the term “unorganized cloud” has no meaning. In this way, the paper is understandable only to the author.
Please provide a flow chart, where you determine the input and the output clearly. Then another workflow is requested to determine the processing step.
Line 195: what do you mean by “Lidar”, lidar point cloud or scanner?
Line 212: how it can be extracted?
Assumptions
Number 3: I think that a and b have the same meaning, so one of them is enough.
3.3. Sub-problems
You apply Voxelization on the point cloud to generate 3 3D matrices. Then you transform these matrices into 2D matrices. Finally, Hatch Edge extraction is applied to 2D matrices. I think that you make a simple problem very complex.
Preprocessing: you filter the obtained point cloud
Please check all “Lidar” words in the paper, sometimes they must be replaced by “scanner” as Line 269.
Between 274 and 275, the use of minimum corner and maximum corner is not clear, what do you mean by them? Lowest and highest? Please explain them and find good expression.
You should replace “eqn.” with “Equation”
In equation 3, what is C
In equation 3, The minimum corner and maximum corner are represented by vectors, is not it? How do you subtract them to get an integer?
Line285: you said: to PG is the output of a voxel filter, which is only used for visualization. That means you can eliminate this step if we do not need to visualize the point cloud, knowing that the point cloud can be visualised without Voxelization.
In the conclusion section, please discuss future works.
Author Response
Thanks for the review work and valuable comments. Please see the attachment for our response.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The paper has been significantly improved and the results is perceived by readers.
I only ask the authors to read back the previous round of revisions and add the part dealing with improving backgrounds with the topic and refs suggested.
Author Response
Reviewer 1: The paper has been significantly improved and the results is perceived by readers.
Response: Thank you. We appreciate the constructive suggest that helped.
Reviewer 1: I only ask the authors to read back the previous round of revisions and add the part dealing with improving backgrounds with the topic and refs suggested.
Response: We have thoroughly revised Section 2.1 with the goal of clarifying the specifications that are required from the sensing system for success in this application. In addition, we have added references (at the last round) to provide background on lidar operation.
We have also added the topic of acoustic sensing as a future research issue. At present, based on our reading, existing acoustic sensors can accurately measure the sensor relative angle to remote sources of acoustic energy. The hatch edges are not sources of acoustic energy; therefore, they would not be detectable unless an acoustic signal was reflected off of them. We are unaware of acoustic sensors capable of providing highly precise relative range and angle measured between the sensor to points on a reflecting surface. If such acoustic sensors exist, their study for this application (and others) would be of great interest to us, but we have not been able to discover such sensors in the literature.
Of the three suggested references, we have included the first. The second, entitled “Measurements of ship noise using an acoustic camera: A first survey,” is only available as a short text abstract, not a full paper. We searched both online and through the University of California interlibrary loan system. Therefore, we cannot include it. The third suggested reference on the topic of noise source characterization is interesting, but does not describe a sensing system meeting the required specifications for this application; therefore, it is not a relevant reference.
Reviewer 3 Report
My concerns have been addressed satisfactorily.
Author Response
Reviewer 3: My concerns have been addressed satisfactorily.
Response: Thank you.
