Comparison between the Employment of a Multibeam Echosounder on an Unmanned Surface Vehicle and Traditional Photogrammetry as Techniques for Documentation and Monitoring of Shallow-Water Cultural Heritage Sites: A Case Study in the Bay of Algeciras
, Raúl González Gallero 1, Juan Rengel 2, Luis Rioja 2, JoaquÃn Callejo 3 and Manuel Bethencourt 4,*Round 1
Reviewer 1 Report
The paper proposes the experimental results regarding the surveys of some shipwrecks in the Bay of Algeciras by using different technologies.
The case study can be considered interesting as it compares the results in terms of instruments performance and data precision, consequently, in my opinion, it is suitable for publication after some minor changes.
The introduction is wide and well-written, however, it does not refer to the numerous previous studies regarding the techniques used to investigate the underwater cultural heritage. Particularly, the introduction’s final part is lacking in references, even if there is wide international literature regarding the use of morpho-acoustic and optical instruments installed on marine drones for coastal geoarchaeological research carried out in shallow and very shallow water sectors. It is sufficient to use the key search “marine drone geoarchaeology” in Google Scholar to get an idea on the topic. So, I suggest modifying the introduction referring to the international contest.
Paragraph 2.1 is wrongly included in the Method section, as it describes the study area and the aim of the paper
In my opinion, information regarding the multibeam installed onboard the marine drone and data regarding the GPS system has to be moved to section 2.2 where the marine drone is described. Instead, section 2.4 could contain only the description of the post-processing phase.
Considering the topic covered in the Introduction, I think that the discussion and conclusion should be modified in order to argue how the experimental results can help to protect the studied shipwrecks from the ongoing climate change effects.
Sincerely, the aim of the paper seems to be more a comparison between the different survey methods in terms of precision and operative problems than the monitoring of the underwater cultural heritage of Algeciras Bay for protection strategies.
Figure 1 needs some important improvements. Please add scale, coordinates and North on the map on the left and coordinates and legend on the map on the right.
In Figures 6 and 7 the Legend labels are not readable.
Figure 8a Please, add the legend and scale of the bathymetric map. Figure 8b It is not possible to read the labels and understand this image.
Figure 9a Please, add the legend and scale of the bathymetric map
In Figures 11 and 12 the labels are not readable a legend is necessary.
Author Response
Ref.: jmse-2454897
Title: Comparison between the employ of a multibeam echosounder on an unmanned surface vehicle and the traditional photogrammetric as techniques for documentation and monitoring of shallow-water cultural heritage sites: A case of study in the Bay of Algeciras
Dear Editor,
Please, find attached our response to reviewers' suggestions/remarks. We would like to thank the reviewers the effort of reading the manuscript and their useful suggestions and encouraging words. A point-by-point response to the comments raised by the reviewers is given in blue text. A list of references used in the response of the reviewer has been included ad the end of this report. Thank you for consider our manuscript for publication.
Response to Reviewer 1
The paper proposes the experimental results regarding the surveys of some shipwrecks in the Bay of Algeciras by using different technologies.
The case study can be considered interesting as it compares the results in terms of instruments performance and data precision, consequently, in my opinion, it is suitable for publication after some minor changes.
The introduction is wide and well-written, however, it does not refer to the numerous previous studies regarding the techniques used to investigate the underwater cultural heritage. Particularly, the introduction’s final part is lacking in references, even if there is wide international literature regarding the use of morpho-acoustic and optical instruments installed on marine drones for coastal geoarchaeological research carried out in shallow and very shallow water sectors. It is sufficient to use the key search “marine drone geoarchaeology” in Google Scholar to get an idea on the topic. So, I suggest modifying the introduction referring to the international contest.
We thank the referee for the suggestion.
We have included several new references of very interesting works carried out with the proposed techniques (see references 20 to 25).
Paragraph 2.1 is wrongly included in the Method section, as it describes the study area and the aim of the paper
Section 2.1 has been moved to the introduction, where it has been adapted.
In my opinion, information regarding the multibeam installed onboard the marine drone and data regarding the GPS system has to be moved to section 2.2 where the marine drone is described. Instead, section 2.4 could contain only the description of the post-processing phase.
The information regarding the multibeam installed onboard the USV and data regarding the GPS system have been moved to section 2.2. Now, section 2.4 only contains information about the post-processing phase.
Considering the topic covered in the Introduction, I think that the discussion and conclusion should be modified in order to argue how the experimental results can help to protect the studied shipwrecks from the ongoing climate change effects.
Sincerely, the aim of the paper seems to be more a comparison between the different survey methods in terms of precision and operative problems than the monitoring of the underwater cultural heritage of Algeciras Bay for protection strategies.
The abstract has been reformulated attending to the reviewer’s suggestion.
Discussion and conclusions have been modified in order to correlate this type of study with the strategies to be followed from the climate change effects, insisting on the idea that when possible, the combination of both techniques allows the most adequate study of the underwater archaeological sites at risk.
Figure 1 needs some important improvements. Please add scale, coordinates and North on the map on the left and coordinates and legend on the map on the right.
Scale, coordinates and North have been added on Figure 1a, and coordinates and legend have been added in Figure 1b.
In Figures 6 and 7 the Legend labels are not readable.
The figure was modified according with the suggestion. In general, all figures (except 2, 4 and 5) have been modified in order to improve their interpretation and readability:
Figure 8a Please, add the legend and scale of the bathymetric map. Figure 8b It is not possible to read the labels and understand this image.
Done.
Figure 9a Please, add the legend and scale of the bathymetric map
Done.
In Figures 11 and 12 the labels are not readable a legend is necessary
Done.
Response to Reviewer 2
1) On line 24,” Abstract:”, It is suggested that please change “unmanned vehicles” to “unmanned surface vehicles”.
We thank the referee for the suggestion.
Done: “unmanned vehicles”, now is “unmanned surface vehicles”.
2) In the abstract, it is necessary to introduce the scientific methods or algorithms used in this study, analyze the research results, and draw scientific conclusions. It is not a simple statement of the underwater cultural heritage scanning process that has been done.
The abstract has been reformulated attending to the reviewer’s suggestion.
3) In the Keywords, It is suggested that please change “unmanned vehicles” to “unmanned surface vehicles”. If it's just an 'unmanned vehicle', readers will have ambiguity.
Done: “unmanned vehicles”, now is “unmanned surface vehicles”.
4) On line 53, for the first occurrence of these abbreviations "EC, UNESCO or ICOMOS", it needs to list the full name.
Done. Now EC is European Union (EU), United Nations Educational, Scientific and Cultural Organization (UNESCO) and International Council on Monuments and Sites (ICOMOS).
5) On line 58, " emerged cultural heritage (ECH)" change to " Emerged Cultural Heritage (ECH)", the abbreviations in other places also need to follow this format.
Done: Underwater Cultural Heritage (UCH) (Emerged Cultural Heritage ECH have been eliminated from the document), Climate Change (CC), Panel on Climate Change (IPCC), Unmanned Surface Vehicles (USV), Autonomous Underwater Vehicles (AUV), Remotely Operated Vehicles (ROV), Unmanned Aerial Systems (UAS), Multibeam Echosounder (MBES), Position and Orientation System for Marine Vessels (POS MV), IMU (Inertial Measurement Unit), GNSS (Global Navigation Satellite System), NTRIP (Network Transport of RTCM via Internet Protocol), Vehicle Control Station (VCS), International Hydrographic Organization (IHO), Total Vertical Uncertainty (TVU), Total Horizontal Maximum Uncertainty (THU), Combined Uncertainty and Bathymetric Estimator (CUBE), Scale-Invariant Feature Transform (SIFT), Speeded-Up Robust Features (SURF), Digital Terrain Model (DTM), Bathymetric Models (DBM) and Digital Elevation Models (DEM), Sound Velocity Profile (SV).
6) The references in the current manuscript are relatively old. The author is expected to refer to the following literature and add relevant papers in recent years, as follows:
Wu G , Zhao M , Cong Y , et al. Algorithm of Berthing and Maneuvering for Catamaran Unmanned Surface Vehicle Based on Ship Maneuverability[J]. Journal of Marine Science and Engineering, 2021, 9(3):289.
Zhong, H. (2020). Underwater cultural heritage and the disputed South China Sea. China Information, 34(3), 361–382.
The references have been included in the manuscript and in the reference list.
7) On line 93, What special symbol is " Rule nº1"?
Now is Rule number 1.
8) There is too much introduction to the content related to special cultural heritage in the article. The main research of this article is photogrammetry and multi beam echodetector methods, but it was not mentioned until line 192.
The archaeological content of the work has been summarized.
9) On line 281, the formula requires a number.
Done. Now this formula is number 1.
10) The title of this manuscript is about the comparison between traditional photography methods and multi beam detection, but we do not understand how to compare the content in " 2. Materials and Methods"? The two comparative research methods require a scientific description of the methods used, such as formula derivation, block diagram description, and so on.
Section 2. Materials and Methods, has a new approach, trying to respond to the reviewers' suggestions
11) On line 349," image of the day 05/07/2015", we cannot find the image, is it " 05/27/2015"?
The date is 05/27/2015 (https://earth.google.com/web/@36.17820826,-5.38276353,109.99084437a,11.07142351d,35y,0.07950007h,25.92794368t,359.9995r?utm_source=earth7&utm_campaign=vine&hl=es)
12) Figure 9. b), The font size of the text in the figure is too small, making it difficult to see the content of the coordinates clearly. Legend needs to be added to multiple curve plots to distinguish different curves.
The figure was modified according with the suggestion. In general, all figures (except 2, 4 and 5) have been modified in order to improve their interpretation and readability.
13) " Table 4. GNSS coordinates of each control point and RMES error calculated.", how is the data in the table obtained? Is the method used described in the previous method?
The method for obtaining the data in Table 4 is now explained.
14) " Figure 11."," Figure 12. ", The font size of the text in the figure is too small, making it difficult to see the content of the coordinates clearly. Legend needs to be added to multiple curve plots to distinguish different curves.
Figures 11 and 12 were modified according with the suggestion.
15) Please add more relevant references to the article.
We have included several new references of very interesting works carried out with the proposed techniques. In the new lest, references, 18, 20 to 26, 40 to 45, and 49.
Reviewer 2 Report
1) On line 24,” Abstract:”, It is suggested that please change “unmanned vehicles” to “unmanned surface vehicles”.
2) In the abstract, it is necessary to introduce the scientific methods or algorithms used in this study, analyze the research results, and draw scientific conclusions. It is not a simple statement of the underwater cultural heritage scanning process that has been done.
3) In the Keywords, It is suggested that please change “unmanned vehicles” to “unmanned surface vehicles”. If it's just an 'unmanned vehicle', readers will have ambiguity.
4) On line 53, for the first occurrence of these abbreviations "EC, UNESCO or ICOMOS", it needs to list the full name.
5) On line 58, " emerged cultural heritage (ECH)" change to " Emerged Cultural Heritage (ECH)", the abbreviations in other places also need to follow this format.
6) The references in the current manuscript are relatively old. The author is expected to refer to the following literature and add relevant papers in recent years, as follows:
Wu G , Zhao M , Cong Y , et al. Algorithm of Berthing and Maneuvering for Catamaran Unmanned Surface Vehicle Based on Ship Maneuverability[J]. Journal of Marine Science and Engineering, 2021, 9(3):289.
Zhong, H.. Underwater cultural heritage and the disputed South China Sea. CHINA INFORMATION. 2020, 34 (3) , pp.361-382
7) On line 93, What special symbol is " Rule nº1"?
8) There is too much introduction to the content related to special cultural heritage in the article. The main research of this article is photogrammetry and multi beam echo detector methods, but it was not mentioned until line 192.
9) On line 281, the formula requires a number. 
10) The title of this manuscript is about the comparison between traditional photography methods and multi beam detection, but we do not understand how to compare the content in " 2. Materials and Methods"? The two comparative research methods require a scientific description of the methods used, such as formula derivation, block diagram description, and so on.
11) On line 349," image of the day 05/07/2015", we cannot find the image, is it " 05/27/2015"?
12) Figure 9. b), The font size of the text in the figure is too small, making it difficult to see the content of the coordinates clearly. Legend needs to be added to multiple curve plots to distinguish different curves.
13) " Table 4. GNSS coordinates of each control point and RMES error calculated.", how is the data in the table obtained? Is the method used described in the previous method?
14) " Figure 11."," Figure 12. ", The font size of the text in the figure is too small, making it difficult to see the content of the coordinates clearly. Legend needs to be added to multiple curve plots to distinguish different curves.
15) Please add more relevant references to the article.
Moderate editing of English language required
Author Response
Ref.: jmse-2454897
Title: Comparison between the employ of a multibeam echosounder on an unmanned surface vehicle and the traditional photogrammetric as techniques for documentation and monitoring of shallow-water cultural heritage sites: A case of study in the Bay of Algeciras
Dear Editor,
Please, find attached our response to reviewers' suggestions/remarks. We would like to thank the reviewers the effort of reading the manuscript and their useful suggestions and encouraging words. A point-by-point response to the comments raised by the reviewers is given in blue text. A list of references used in the response of the reviewer has been included ad the end of this report. Thank you for consider our manuscript for publication.
Response to Reviewer 2
1) On line 24,” Abstract:”, It is suggested that please change “unmanned vehicles” to “unmanned surface vehicles”.
We thank the referee for the suggestion.
Done: “unmanned vehicles”, now is “unmanned surface vehicles”.
2) In the abstract, it is necessary to introduce the scientific methods or algorithms used in this study, analyze the research results, and draw scientific conclusions. It is not a simple statement of the underwater cultural heritage scanning process that has been done.
The abstract has been reformulated attending to the reviewer’s suggestion.
3) In the Keywords, It is suggested that please change “unmanned vehicles” to “unmanned surface vehicles”. If it's just an 'unmanned vehicle', readers will have ambiguity.
Done: “unmanned vehicles”, now is “unmanned surface vehicles”.
4) On line 53, for the first occurrence of these abbreviations "EC, UNESCO or ICOMOS", it needs to list the full name.
Done. Now EC is European Union (EU), United Nations Educational, Scientific and Cultural Organization (UNESCO) and International Council on Monuments and Sites (ICOMOS).
5) On line 58, " emerged cultural heritage (ECH)" change to " Emerged Cultural Heritage (ECH)", the abbreviations in other places also need to follow this format.
Done: Underwater Cultural Heritage (UCH) (Emerged Cultural Heritage ECH have been eliminated from the document), Climate Change (CC), Panel on Climate Change (IPCC), Unmanned Surface Vehicles (USV), Autonomous Underwater Vehicles (AUV), Remotely Operated Vehicles (ROV), Unmanned Aerial Systems (UAS), Multibeam Echosounder (MBES), Position and Orientation System for Marine Vessels (POS MV), IMU (Inertial Measurement Unit), GNSS (Global Navigation Satellite System), NTRIP (Network Transport of RTCM via Internet Protocol), Vehicle Control Station (VCS), International Hydrographic Organization (IHO), Total Vertical Uncertainty (TVU), Total Horizontal Maximum Uncertainty (THU), Combined Uncertainty and Bathymetric Estimator (CUBE), Scale-Invariant Feature Transform (SIFT), Speeded-Up Robust Features (SURF), Digital Terrain Model (DTM), Bathymetric Models (DBM) and Digital Elevation Models (DEM), Sound Velocity Profile (SV).
6) The references in the current manuscript are relatively old. The author is expected to refer to the following literature and add relevant papers in recent years, as follows:
Wu G , Zhao M , Cong Y , et al. Algorithm of Berthing and Maneuvering for Catamaran Unmanned Surface Vehicle Based on Ship Maneuverability[J]. Journal of Marine Science and Engineering, 2021, 9(3):289.
Zhong, H. (2020). Underwater cultural heritage and the disputed South China Sea. China Information, 34(3), 361–382.
The references have been included in the manuscript and in the reference list.
7) On line 93, What special symbol is " Rule nº1"?
Now is Rule number 1.
8) There is too much introduction to the content related to special cultural heritage in the article. The main research of this article is photogrammetry and multi beam echodetector methods, but it was not mentioned until line 192.
The archaeological content of the work has been summarized.
9) On line 281, the formula requires a number.
Done. Now this formula is number 1.
10) The title of this manuscript is about the comparison between traditional photography methods and multi beam detection, but we do not understand how to compare the content in " 2. Materials and Methods"? The two comparative research methods require a scientific description of the methods used, such as formula derivation, block diagram description, and so on.
Section 2. Materials and Methods, has a new approach, trying to respond to the reviewers' suggestions
11) On line 349," image of the day 05/07/2015", we cannot find the image, is it " 05/27/2015"?
The date is 05/27/2015 (https://earth.google.com/web/@36.17820826,-5.38276353,109.99084437a,11.07142351d,35y,0.07950007h,25.92794368t,359.9995r?utm_source=earth7&utm_campaign=vine&hl=es)
12) Figure 9. b), The font size of the text in the figure is too small, making it difficult to see the content of the coordinates clearly. Legend needs to be added to multiple curve plots to distinguish different curves.
The figure was modified according with the suggestion. In general, all figures (except 2, 4 and 5) have been modified in order to improve their interpretation and readability.
13) " Table 4. GNSS coordinates of each control point and RMES error calculated.", how is the data in the table obtained? Is the method used described in the previous method?
The method for obtaining the data in Table 4 is now explained.
14) " Figure 11."," Figure 12. ", The font size of the text in the figure is too small, making it difficult to see the content of the coordinates clearly. Legend needs to be added to multiple curve plots to distinguish different curves.
Figures 11 and 12 were modified according with the suggestion.
15) Please add more relevant references to the article.
We have included several new references of very interesting works carried out with the proposed techniques. In the new lest, references, 18, 20 to 26, 40 to 45, and 49.
Response to Reviewer 1
The paper proposes the experimental results regarding the surveys of some shipwrecks in the Bay of Algeciras by using different technologies.
The case study can be considered interesting as it compares the results in terms of instruments performance and data precision, consequently, in my opinion, it is suitable for publication after some minor changes.
The introduction is wide and well-written, however, it does not refer to the numerous previous studies regarding the techniques used to investigate the underwater cultural heritage. Particularly, the introduction’s final part is lacking in references, even if there is wide international literature regarding the use of morpho-acoustic and optical instruments installed on marine drones for coastal geoarchaeological research carried out in shallow and very shallow water sectors. It is sufficient to use the key search “marine drone geoarchaeology” in Google Scholar to get an idea on the topic. So, I suggest modifying the introduction referring to the international contest.
We thank the referee for the suggestion.
We have included several new references of very interesting works carried out with the proposed techniques (see references 20 to 25).
Paragraph 2.1 is wrongly included in the Method section, as it describes the study area and the aim of the paper
Section 2.1 has been moved to the introduction, where it has been adapted.
In my opinion, information regarding the multibeam installed onboard the marine drone and data regarding the GPS system has to be moved to section 2.2 where the marine drone is described. Instead, section 2.4 could contain only the description of the post-processing phase.
The information regarding the multibeam installed onboard the USV and data regarding the GPS system have been moved to section 2.2. Now, section 2.4 only contains information about the post-processing phase.
Considering the topic covered in the Introduction, I think that the discussion and conclusion should be modified in order to argue how the experimental results can help to protect the studied shipwrecks from the ongoing climate change effects.
Sincerely, the aim of the paper seems to be more a comparison between the different survey methods in terms of precision and operative problems than the monitoring of the underwater cultural heritage of Algeciras Bay for protection strategies.
The abstract has been reformulated attending to the reviewer’s suggestion.
Discussion and conclusions have been modified in order to correlate this type of study with the strategies to be followed from the climate change effects, insisting on the idea that when possible, the combination of both techniques allows the most adequate study of the underwater archaeological sites at risk.
Figure 1 needs some important improvements. Please add scale, coordinates and North on the map on the left and coordinates and legend on the map on the right.
Scale, coordinates and North have been added on Figure 1a, and coordinates and legend have been added in Figure 1b.
In Figures 6 and 7 the Legend labels are not readable.
The figure was modified according with the suggestion. In general, all figures (except 2, 4 and 5) have been modified in order to improve their interpretation and readability:
Figure 8a Please, add the legend and scale of the bathymetric map. Figure 8b It is not possible to read the labels and understand this image.
Done.
Figure 9a Please, add the legend and scale of the bathymetric map
Done.
In Figures 11 and 12 the labels are not readable a legend is necessary
Done.
Round 2
Reviewer 2 Report
(1) On line 432, " digital Bathymetric Models (DBM)" change to " Digital Bathymetric Models (DBM)", the abbreviations in other places also need to follow this format.
(2) "Figure 9. b)", " Figure 11."," Figure 12. ", The legend needs to be added to multiple curve plots to distinguish different curves, as follows Figure. It is necessary to display different curves with different linetypes and colors to distinguish different data.
Moderate editing of English language required
Author Response
Ref.: jmse-2454897
Title: Comparison between the employ of a multibeam echosounder on an unmanned surface vehicle and the traditional photogrammetric as techniques for documentation and monitoring of shallow-water cultural heritage sites: A case of study in the Bay of Algeciras
Dear Editor,
Please, find attached our response to Reviewer 2 suggestions/remarks. We would like to thank the Reviewer 2 the effort of reading the manuscript again and his/her useful suggestions and encouraging words. A point-by-point response to the comments raised by the reviewers is given in blue text. A list of references used in the response of the reviewer has been included ad the end of this report. Thank you again for consider our manuscript for publication.
Comments from the editor and reviewers:
Reviewer 2
We thank the referee for the new suggestions.
(1) On line 432, " digital Bathymetric Models (DBM)" change to " Digital Bathymetric Models (DBM)", the abbreviations in other places also need to follow this format.
Done: Digital Bathymetric Models (DBM)
Abbreviations in other places:
- RTK is Real Time Kinematic.
- SV is SVP: Sound Velocity Profile.
- In Figure 8: Stern-port Side (S-P) and Stern-starboard Side (S-S).
(2) "Figure 9. b)", " Figure 11."," Figure 12. ", The legend needs to be added to multiple curve plots to distinguish different curves, as follows Figure. It is necessary to display different curves with different linetypes and colors to distinguish different data.
Done.
Comments on the Quality of English Language: Moderate editing of English language required
The text has been proofread by a native British English speaker.
