Mineralogical Mapping with Accurately Corrected Shortwave Infrared Hyperspectral Data Acquired Obliquely from UAVs

Round 1

Reviewer 1 Report

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Comments for author File: Comments.pdf

Author Response

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Reviewer 2 Report

The authors present an approach to carry out the geometric and radiometric correction for the shortwave infrared hyperspectral data collected obliquely from UAVs. However, a lot of flaws presented in this manuscript, and the details about the reviews of this manuscript are as follows:

 

1. Abstract: appli-cations ==>> applications; the sentence of “appli-cations are mostly confined to nadir orientations.”is vague.
2. Introduction: I am missing a good introduction, please consider cite the following works that were related to the application to geological mapping using LiDAR (you will find others in scientific databases):

Mapping clay minerals in an open-pit mine using hyperspectral and LiDAR data

Automated measurements of discontinuity geometric properties from a 3D-point cloud based on a modified region growing algorithm

Close range hyperspectral imaging integrated with terrestrial LiDAR scanning applied to rock characterization at centimeter scale

Feasibility study of ore classification using active hyperspectral LiDAR

3. Figure 3: This outcrop is the perfect case for the study. However, there always is much vegetation covered on the surface of the outcrop. Is your algorithm available for this situation? Please provide more explanation for this. Furthermore, please add a scale for this image.
4. Where is the subsection of 3.4?
5. The authors have provided the details for geometric and radiometric corrections. But, there are few contents related to the geology interpretation based on the collected data. The title of this paper is “geological mapping……”, and I have no idea how do you conduct the stratigraphic interpretation as shown in Figure 12.
6. A comparison between the UAV-based method and other measurements is highly suggested to be made to estimate the accuracy of the proposed method in this study. This part could be placed in the Discussions section.

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

Good paper.

page 1: remove hyphen: appli-cation

page 2: accurately georeferencing -> accurate georeferencing

page 11 & references: I think the authors should accredit the original papers of the minimum wavelength mapping method. See: 
https://doi.org/10.1016/j.pss.2014.06.009
https://doi.org/10.1016/j.jag.2017.09.008
https://doi.org/10.1016/j.jag.2019.02.013

Please see attached file for detailed comments.

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

Although the authors have replied to some of my questions, I still have many concerns about this manuscript.

 

1. Author list: I find there is a change on the authors’ list, and please explain it.
2. Introduction: I am still missing a good introduction. I have seen many studies using the image-based or laser-based method in geology science, but some are unnecessary. I want to know the necessity of using this method in this research. I hope the authors could give more explanations. The descriptions in the Introduction are not quite convincing.
3. If the proposed method can be only applied to the outcrop with good exposure, I will concern the broad international interest and generic interest of this study. Because in most cases, the outcrops are often covered by vegetation.
4. Please verify your findings using a field survey or laboratory work (e.g., mineral analysis).
5. How did you identify the sedimentary layers and faults using your proposed method?

Author Response

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Author Response File: Author Response.pdf