Drone-Borne Electromagnetic (DR-EM) Surveying in The Netherlands: Lab and Field Validation Results
and Edvard Ahlrichs 1
Round 1
Reviewer 1 Report
1. Is it possible to convert soil salinity data from TDS ppm to ECe (Electrical Conductivity of Saturation Extract). ECe is a more easily understood term in soil salinity study.
2. Is it possible to come up with a quantitative assessment of actual field data and measured data matching that can be helpful in calibration inversion data?
3. Is it possible for including an application in the data collection system that will through some trial run identify all necessary conditions for the application of the drone technology in the field?
4. Is it possible to have more sources of noise such as metal concentrations in soil, dust and particles in the air, wind direction, sunlight, soil dryness, etc.?
5. Have there been improvements in 2022 drones to rectify some of the noise and data calibrations discussed in this paper?
6. Provide a list of abbreviations used in this paper.
Author Response
Q:1. Is it possible to convert soil salinity data from TDS ppm to ECe (Electrical Conductivity of Saturation Extract). ECe is a more easily understood term in soil salinity study.
R: In this work we present the EC bulk as also the conversion of EC bulk to TDS (which relates the bulk conductivity with the fluid conductivity). In Netherlands, hydrogeologist prefer to see TDS, as a mean to understand the water quality. We would like to stick with TDS.
Q:2. Is it possible to come up with a quantitative assessment of actual field data and measured data matching that can be helpful in calibration inversion data?
R:We added section 3.5
Q:3. Is it possible for including an application in the data collection system that will through some trial run identify all necessary conditions for the application of the drone technology in the field?
R:We added section 3.5
Q:4. Is it possible to have more sources of noise such as metal concentrations in soil, dust and particles in the air, wind direction, sunlight, soil dryness, etc.?
R:We added section 2.7
Dust, particles in the air do not effect the EM wave, at least not in measurable way. Sunlight, has an effect on the temperature of the coils. Thus, operating in a range different that the suggested by the manufactures, should be used in caution. Soil dryness is not a source of noise. In essence, very dry soil is similar to air. The signal is losing energy (i.e. depth of investigation) based on how conductive the envenomed is. Yet, this is still the target of the geophysical survey, resistivity structure of earth.
Q:5. Have there been improvements in 2022 drones to rectify some of the noise and data calibrations discussed in this paper?
AFAIK, there are no drone developments to address those issues, due to the limited market. Perhaps if more work is published, drone manufactures, will start addressing those issues.
Q:6. Provide a list of abbreviations used in this paper.
We added section 0
Reviewer 2 Report
The authors aimed to demonstrate the feasibility of a new way of spectral surveying different targets on Earth by using instruments mounted onboard drones.
It is difficult to assess the relevance and effectiveness of the proposed technology because of the way it is presented. I consider confusing the flow of ideas, as well as their formulation, and as a result the results are unconvincing.
That is why I invite the authors to review the entire manuscript in order to make it clear and preferably more concise.
Moreover, since the subject is about a technology, I suggest using the well-known Technology Readiness Level (TRL) scale to describe how the claimed technological maturity of drone-borne electromagnetic surveying has been achieved.
Author Response
Q: The authors aimed to demonstrate the feasibility of a new way of spectral surveying different targets on Earth by using instruments mounted onboard drones.
It is difficult to assess the relevance and effectiveness of the proposed technology because of the way it is presented. I consider confusing the flow of ideas, as well as their formulation, and as a result the results are unconvincing. That is why I invite the authors to review the entire manuscript in order to make it clear and preferably more concise.
We re-wrote some parts of the MS to make it more clear. We hope it is up to your expectations.
Q:Moreover, since the subject is about a technology, I suggest using the well-known Technology Readiness Level (TRL) scale to describe how the claimed technological maturity of drone-borne electromagnetic surveying has been achieved.
We added a section discussing the TRL level on chapter 5.
Reviewer 3 Report
Dear Editor/Authors,
I have read the manuscript remotesensing-1819270 entitled “Drone-borne Electromagnetic (DR-EM) Surveying in The Netherlands: Lab and field validation results”, written by Karaoulis et collab. and submitted for publishing to Remote Sensing Journal. The paper presents interesting outcomes of using UAV-s in some study cases by an improved methodological framework. For this reason the paper deserves publication. Before that, some major improvements should be addressed by the authors.
This assessment is due to some important drawbacks of the manuscript. A first major issue is presented by the overall feature: it is a technical report, in which the links with UAVs usage in similar methodological and environmental settings are almost missing (and this can be easily seen on the references used – and more, references are used just in the first part of the Introduction). Also, the introduction of a paper should be an invitation to read the paper in a broader (internationally) framework, and not a presentation of specific issues of the authors. These aspects should characterize a second part (Data and method). The discussion part should address, again, a broader spectrum of similar research, and the improvements of the current research. In my opinion I suggest to the authors to spend 2-3 weeks for restructuring the paper, in order to make the results readable for scientific community. Of course by keeping technical improvements, but emphasizing on the various ways in which the presented manuscript moves forwards the knowledge in the UAVs field (also by highlighting limitations, and the possibilities for reproducing the work).
Other technical suggestions in the pdf file attached.
Congratulations for your work, hoping in a much more scientific soundness of the improved version of the paper!
Comments for author File: 
Comments.pdf
Author Response
I have read the manuscript remotesensing-1819270 entitled “Drone-borne Electromagnetic (DR-EM) Surveying in The Netherlands: Lab and field validation results”, written by Karaoulis et collab. and submitted for publishing to Remote Sensing Journal. The paper presents interesting outcomes of using UAV-s in some study cases by an improved methodological framework. For this reason the paper deserves publication. Before that, some major improvements should be addressed by the authors.
Q:This assessment is due to some important drawbacks of the manuscript. A first major issue is presented by the overall feature: it is a technical report, in which the links with UAVs usage in similar methodological and environmental settings are almost missing (and this can be easily seen on the references used – and more, references are used just in the first part of the Introduction).
R: Our aim of this paper is the use of drones with EM. Not general drones in earth sciences, our paper has limited scope. We added lines 75-77.
Q:Also, the introduction of a paper should be an invitation to read the paper in a broader (internationally) framework, and not a presentation of specific issues of the authors. These aspects should characterize a second part (Data and method).
R: We added lines 62-73 in the introduction, to discss a broader adpctd.
R; We feel that we are not suited to discuss in this paper, all aspects and applications of Drones. We added line 75-77 to limit the scope of this paper.
Q:The discussion part should address, again, a broader spectrum of similar research, and the improvements of the current research. In my opinion I suggest to the authors to spend 2-3 weeks for restructuring the paper, in order to make the results readable for scientific community. Of course by keeping technical improvements, but emphasizing on the various ways in which the presented manuscript moves forwards the knowledge in the UAVs field (also by highlighting limitations, and the possibilities for reproducing the work).
R: We added a paragraph to the conclusion section. Overall, we would like to mention that our work is not moving forward of the UAVs field, we just only focus on a special geophysical topic, EM surveys using drones.
Q:Other technical suggestions in the pdf file attached.
R: All comments are fixed in the revised MS
Congratulations for your work, hoping in a much more scientific soundness of the improved version of the paper!
We thank reviewer for his comment
Round 2
Reviewer 2 Report
The revised manuscript is better but it still needs improvements concerning the clarity of approaches and implementation, as well as concerning the scientific writing.
I) With regard to the first requirement, since the subject is about a technology, I kindly ask the authors to reformulate the text and use the Technology Readiness Level (TRL) scale to describe how the claimed technological maturity of drone-borne electromagnetic surveying has been achieved.
I already asked this in my first Report but I find the response unsatisfactory.
That is why I invite the authors to make an informative, clear description in the "Introduction" of the TRL found at the beginning of the work (that is, please rephrase in your manuscript “what was already known?” with TRL link). Then, still in the Introduction, I invite the authors to reveal concisely but clearly their scope and the intended final TRL. Next, in the description of the methods and experiment (sections 2 to 4), the suggestion to the authors is to reformulate the text and refer how they have challenged and crossed one or more TRLs. In the Conclusion, I invite the authors to make an informative, clear description of the TRL achieved. Again, how the final TRL was achieved should be written in sections 2 to 4.
This way, I expect the text will be clearer, more to the point and hopefully more concise, not only for me, this reviewer, but especially for the readers.
Please take into account the official definitions of TRLs:
TRL 1 – basic principles observed
TRL 2 – technology concept formulated
TRL 3 – experimental proof of concept
TRL 4 – technology validated in lab
TRL 5 – technology validated in relevant environment (industrially relevant environment in the case of key enabling technologies)
TRL 6 – technology demonstrated in relevant environment (industrially relevant environment in the case of key enabling technologies)
TRL 7 – system prototype demonstration in operational environment
TRL 8 – system complete and qualified
TRL 9 – actual system proven in operational environment (competitive manufacturing in the case of key enabling technologies or in space)
II) With regard to the scientific writing, I made some corrections, suggestions and recommendations in the file attached (not all needed, be aware of this).
At the same time, I invite the authors to revise LINE BY LINE the final manuscript, after taking into account point I above and the improvements required by the other reviewers.
Comments for author File: Comments.pdf
Author Response
We thank the reviewer for his comments and editing. We added some TRL level texts in various places. We would to comment that our role is purely scientific and the TRL is not something we deal with with our regular tasks. Our aim is to propose some steps and we perform with the community so others can pick up and further improve.
We understand though the need for this section but we are not fully aware what TRL level we have achieved. We hope this estimation is in par with reviewer expectations.
Reviewer 3 Report
The authors clarified and improved the manuscript.
Author Response
We thank reviewer for his comments.
