UAVs and 3D City Modeling to Aid Urban Planning and Historic Preservation: A Systematic Review

Round 1

Reviewer 1 Report (Previous Reviewer 1)

Comments and Suggestions for Authors

I had previously reviewed a version of this article. Overall the paper has improved. Based on my previous review and the current version, I have the following comments:

- Please mention the research problem in the abstract. It is currently missing

-  Please elaborate on the problem in the introduction; is the purpose of UAV usage a technological advancement, or is it aimed at addressing an existing issue? This is not clear currently.

- As previously indicated, Digital twins and 3D models are separate entities. The authors have removed digital twins from almost all of the paper but may have missed removing the term from search strings and section 2.3. Please remove it for consistency. Similarly, preservation should be "Urban Preservation".

- Figure 1 is of very low quality and unreadable in its current state, as recommended in my last review; please show what each color/cluster refers to and why it is important. The authors have added a table, but it doesn't explain what is important in Figure 1. You can also consider removing the figure due to no value addition.

-  The PRISMA conditions are not clear currently. PRISMA has certain conditions that must be met in associated review studies. For instance, the authors can read  section 2.2 of the following article: https://www.sciencedirect.com/science/article/pii/S004016252100175X

 

Comments on the Quality of English Language

Minor editing needed.

Author Response

Thank you for the feedback. We have made the following revisions:

• We have revised the abstract to include a clear statement of the research problem, ensuring that readers can quickly grasp the main focus of our study.
• We have expanded upon the problem statement in the introduction section. We believe that UAV usage is not solely driven by technological advancement but primarily aimed at addressing existing issues within the fields of urban planning and historic preservation in order to better apply technological advancements in 3D city modeling and remote sensing. This addition provides a clearer understanding of the purpose behind our research.
• Regarding the distinction between "digital twin" and "3D modeling," we appreciate the previous feedback. We would like to retain the term "digital twin" in this review, as a number of the papers we have reviewed mentioned the transition from 3D modeling to digital twins, and by including "digital twin," we aim to encourage further research in this emerging area once the foundation of 3D modeling is well-established. To ensure consistency, we have updated most references from "preservation" to "historic preservation." This adjustment better aligns with our focus, as historic preservation is synonymous to terms such as cultural heritage and urban conservation. However, we've retained "preservation" as a search term to ensure a broader scope in our search results.
• We have enhanced Figure 1 by adding additional explanations for the main clusters, making it more informative and easier to understand. We have also improved the overall quality of the figure to enhance its readability.
• We have carefully reviewed the PRISMA conditions and have provided additional explanations in section 2.5 to ensure that our review study aligns with these requirements. We changed the title of the table to “study search strategy”. We have incorporated the guidelines outlined in the PRISMA checklist and the suggested article.

Reviewer 2 Report (Previous Reviewer 2)

Comments and Suggestions for Authors

The authors approached properly to my comments. I suggest to accept it from my side.

Author Response

We sincerely thank Reviewer 2 for the feedback and acceptance of our revisions.

Reviewer 3 Report (New Reviewer)

Comments and Suggestions for Authors

This manuscript make a review about drone imagery for urban planning and preservation, and concluded some Shortcomings. The paper also discussed current limitations with UAV applications and possible countermeasures as well as future prospects. It’s an interesting and important paper to know the Urban Planning and Preservation in the view of UAV.

 

Some comments in should be addressed.

1. The Figure 1 should be more larger to clearly show the kewword characters

2. Figure 2 is not clear, please improve the quality

3. Please reconstructure the figure 3, it seems not quite informative.

4. Page 2, the last paragraph, I think 1, 2, 3 should be replaced by firstly, secondly, and thirdly.

Comments on the Quality of English Language

The English is qualified.

Author Response

Thank you for your feedback on the manuscript. We have made the following revisions:

• We have improved the quality and size of Figure 1 to ensure that the keyword characters are clearly visible and easier to interpret.
• We have replaced Figure 2 with a higher-quality VOSviewer graph. This new representation enhanced the clarity of the data and better illustrate keyword occurrences.
• We have restructured Figure 3 by adding additional information to make it more informative, providing a better understanding of the search process.
• We have replaced the numerical indicators (1, 2, 3) with the terms "firstly," "secondly," and "thirdly" to improve the readability and flow of the text.

Reviewer 4 Report (New Reviewer)

Comments and Suggestions for Authors

I think this is a good review paper, which provides a comprehensive review of the recent development of UAV and 3D modelling. I will recommend to my students to go over the listed literature and study the presentation of the literature review.

Comments on the Quality of English Language

I think the English language is fine. Some minor editorial and term inconsistencies, but no major concerns.

Author Response

We sincerely thank Reviewer 4 for the thoughtful review and acceptance of our manuscript. We have carefully reviewed the manuscript for further improvements.

Round 2

Reviewer 1 Report (Previous Reviewer 1)

Comments and Suggestions for Authors

Thank you for addressing my comments. 

Comments on the Quality of English Language

Minor editing needed

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Thank you for sharing the review article "Drones and Digital Twins to Aid Urban Planning and Preservation: A Systematic Review" with me. I have the following comments:

- Line 2 vintage points and capabilities... please be specific about what points and what type of capabilities?

- 3D models and digital twins are used synonymously in the paper. These are very different concepts. Not all 3D models are Digital Twins, and vice versa. There is a conceptual misunderstanding throughout the paper. Please revise carefully.

- What repositories were used to review the articles? This is not clear in the abstract.

- There is a lot of over-promising in the paper. As per the abstract, the paper covers the UAV technology to enhance building information systems and planning support systems to respond to the challenges of disaster response, climate mitigation and adaptation, cultural heritage documentation, and public engagement with the built environment. That is a lot of work and well beyond what is reported in the paper. Each of these, such as building information systems or challenges of disaster response systems, can be a review paper on its own. Because of this, the paper has too much breadth but no scientific depth. Please revise carefully and focus on limited aspects, but dig deep into the details and concepts. 

- It is important that the authors clearly define and set the scope of what they mean by digital twin in this paper. To the reviewer, it seems as if the authors have confused 3D modeling for digital twins and used digital twins as a mere buzzword on its face value instead of doing justice to the concept and going deep into the concept and how DTs are linked to urban preservation. 

- The authors can consider splitting the paper and focusing on either DTs or 3D models but should go deep into the relevant articles. From the current version, 3D modeling would be a more suitable approach instead of DTs. This is also evident in the section where the authors have presented the research question i.e., the guiding question for this paper is how UAV technology can be effectively applied as a 3D modeling tool in urban planning and preservation, considering the specific needs of these domains, current gaps within the published articles, and what limitations significantly impact its implementation. Interestingly the question doesn't mention DTs or the promises made in the abstract.

-  Please list the objectives of the study in numbered format to be clear to the readers.

- The novelty and additionally of the study are also not clear and not elaborated on. Please focus on these aspects as they will add weight to the study.

- The reviewer has concerns about the use of 3D and Digital twins with the operator OR in the keywords (in search strings). This would mean the keywords may result in papers on either of the two words, which would basically mean papers with the term 3D would be retrieved instead of Models or Digital Twins, hence resulting in irrelevant articles.  The same issue exists with urban planning OR preservation. Preservation is not always about urban planning, hence again leading to irrelevant articles. 

- In contrast to what is promised in the abstract, the search strings do not show how the authors retrieved and reviewed articles on disaster response, climate mitigation and adaptation, cultural heritage documentation, and public engagement with the built environment. The strings are simplistic with a focus on UAVs, Urban planning, and 3D/DTs. 

- It is important to clearly discuss the limits on the article selections and how they were applied to the strings. The authors should add a table and list the number of articles against each string and step on each repository. 

- Please add visual enhancement in the form of boxes/arrows to visualize what is important in Figure 1. Currently, the image doesn't convey a clear message but shows complicated connections of keywords. While the reviewer understands that this is the default output of Vosviewer, it is important that researchers add identification marks or shapes to the image to make it meaningful.

- The authors have provided a PRISMA diagram as a method of retrieving articles but have not clarified and discussed in detail how PRISMA conditions were met around article shortlisting. This needs further explanation.

- The issue of over-promising is evident in the results as well. It is not clear how disaster response, climate mitigation and adaptation, cultural heritage documentation, and public engagement with the built environment are covered in the study. These may be added to results as separate headings and explained in detail.

- Discussions and concussions should be separated to focus on each section in detail.   

 

Comments on the Quality of English Language

The language is fine and readable.

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript is an interesting contribution to urban planning and preservation. It reviews the current state-of-the art of using UAV data for 3D modeling of cities from different perspectives. I suggest accepting the manuscript after having into account the following suggestions.

 

1) Introduction, Line 22 , "...(UAV), commonly referred to as drones": In my concept, UAVs and drone are not necessarily the same. UAVs include drones, but also other type of vehicles. Although, I understand this terminology varies from expert to expert, I would invite to check if actually thorugh the manuscript it is covered different UAVs; if so, I would change the title from "Drones..." to "UAVs".

2) Section 3.5, lines 375-381, "Thirdly...". This is an important highlight that current researchers are investigating. I invite the authors to check the work [1]. The authors use drone imagery and digital twins towards the post-earthquake damage assessment of historical buildings (stone masonry constructions).

[1] https://www.sciencedirect.com/science/article/pii/S0926580523001024

3) Section 4: From my experience, one major drawback is the image acquicision. In today's practice it is mostly used manual operation by the pilot which can be time consuming. For big infrastructure mainly it is necessary the automation of this. There are researchers working actively in these (e.g., [2] [3] [4]). I would suggest to explore in this direction.

[2] https://www.sciencedirect.com/science/article/pii/S0926580522000875

[3] https://www.sciencedirect.com/science/article/pii/S0141029622012603

[4] https://link.springer.com/article/10.1007/s11803-023-2167-y

 

4) Section 4.1, lines 432-435 "For instance, ..." Add a reference to support this.

 

5) Section 4.3: Although interesting, this section does not fit properly with the rest of the manuscript. I would try to reduce considerably its content as at certain point it just went verbose.

 

6) Section 4.4, lines 545-547. Need a reference

 

7) Section 4.5, lines 580-583 "According to....". I would not limit to the commercial softwares. There are open source software that researchers in computer vision and other areas use such as Colmap [5] or Meshroom [6]. They might not be optimized as the commercial ones but offer powerful tools for development of new methodologies such as those required for generation of 3D digital twin models.

[5] https://openaccess.thecvf.com/content_cvpr_2016/papers/Schonberger_Structure-From-Motion_Revisited_CVPR_2016_paper.pdf

[6] https://dl.acm.org/doi/abs/10.1145/3458305.3478443

 

8) Section 5. This section is out of the scope of the literature review paper. Not necessary at all. I suggest removing the full section -- it does not add any value and instead it looks like it was included forcedly.

 

9) Section 6. Line 717. What about all the other countries that have been affected by current wars?. I would suggest to do not focus in a single country -- not that professional in my opinion.

 

10) Section 7. Usually a literature review is made to identify the gaps in research for new investigations. It would be interesting to mention what the authors plan in the future studies to do in the future having identified those lacks in this paper. This can be beneficial in the future when the authors want to claim some novelty in their future works.