Underwater 3D Scanning System for Cultural Heritage Documentation

Round 1

Reviewer 1 Report

The introduction clearly presents the type of research addressed, providing a complete overview of the state of the art of metric documentation of cultural heritage in underwater environments, accompanied by pertinent bibliographic references.

Even more detailed is the description of the instrumentation and methodologies addressed in testing the survey technique object of the study, of which both the positive and negative aspects are highlighted, as well as the future scenarios.

In general, the study is very interesting and offers an important contribution to the development and improvement of underwater surveying techniques.

English is well written and easily understood.

Publication in the current version is recommended.

Author Response

Dear reviewer,

thank you for your positive response! NevertheIess, I made some supplements according to the remarks of the other reviewers. See the attached file.

Author Response File: Author Response.pdf

Reviewer 2 Report

In this paper, a novel 3D scanning system based on structured illumination is introduced which supports cultural heritage documentation and measurement tasks in underwater environments. In general, the topic in this paper is very helpful and important. However, the paper needs revision before acceptance.

1. In introduction, the authors mention the sonar system. However, the mentioned sonar systems in [18-22] cannot provide high-resolution image. For underwater imaging, the synthetic aperture sonar (SAS) [R1-4] is considered to be the highest equipment, which can be used for cultural heritage documentation and measurement. With SAS image, the 3D image can be further obtained. However, this high-resolution technique has not been reviewed in the introduction. The authors should comprehensively review this technique and conduct the comparison between this technique and authors’ method. This would helpful for work in the underwater field.

[R1] Nahid Nadimi, et al．Efficient Detection of Underwater Natural Gas Pipeline Leak Based on Synthetic Aperture Sonar (SAS) Systems．Journal of Marine Science and Engineering. 2021, 9(11), 1273

[R2]X. Zhang，et al．Multireceiver SAS imagery based on monostatic conversion．IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing，2021，14：10835-10853．

[R3] P. Yang, et al．Effect of Non-unifrom Sampling on Sonar Focusing．2022 14th International Conference on Communication Software and Networks (ICCSN)，2021，DOI: 10.1109/ICCSN55126.2022.9817582．

[R4] Albert Reed, et al．Implicit Neural Representations for Deconvolving SAS Images．OCEANS 2021，2021，DOI: 10.23919/OCEANS44145.2021.9705799．

2. Lines  143-147, the authors said that ‘has a standard measurement distance of 2 m ± 0.5 m and the second one (S2) of 1.3 m ± 0.5 m. Sensor S1 has a field of view of approximately 0.9 m x 0.8 m 144 (at 2.0 m distance) and S2 of 0.7 m x 0.6 m (at 1.3 m distance). The standard spatial resolution lies between 0.8 and 1.0 mm but this can be changed to 0.4 to 0.5 mm’, the reviewers wander to know whether the detecting range is about 3 m. If this was true, the detecting range is too close. Besides, the reviewer further wanders to know how to determine and measure the resolution.

3. The camera which highly depends on muddy water is used by authors’ equipment. The reviewer wanders to know the reliability of this sensor working in muddy water.

4. ROV stability would be highly affected by ocean. Consequently, the ROV stability would affect the result quality. The reviewer wanders to know how to solve this problem.

5. The results conducted based on real data are very interesting. However, more discussions such as advantages compared to other technique like SAS would be helpful. At this point, the comparison is suggested to be added.

Author Response

Dear reviewer,

according to your hints I made some supplements. I hope, the new parts of the manuscript match your requests. According SAS I do not really have an idea concerning the performance, but I'll be concerned with in the future.

For details see the attaches file.

Author Response File: Author Response.pdf

Reviewer 3 Report

The authors are dealing with the topic of cultural 3D micro locations scanning under water. They developed archaeological sites scanning and made some test in freshwater and salt water. Cultural heritage documentation was discussed.

These are my observations:

-       The research is well conducted, the authors know what they are doing,

-       The paper is well written and I could not find any complaints

-       Maybe a title of the chapter 4 could be Discussion and Conclusions

-       It would be nice to know the dimensions of the system in figure 2

-     in the part explaining the possible cave scanning (line 418) narrow passages were explained. It would be good for the reader to know some approximate dimensions of caves that could be scanned

-       it would be interesting to read authors opinion of system going into mass production and its possibilities

-       maybe such system could be also used for touristic purposes. Is there a possibility of connecting 3D scanning underwater and above water data.

These are just minor remarks. I congratulate authors on well conducted research and well written paper and wish them a good luck in their further research.

 

Author Response

Dear reviewer,

thanks for your hints! I added some text according your remarks (see attached file) and entitled chapter 4 as Discussion and Conclusions.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The paper is improved after revision.