Performance Testing of Optical Flow Time Series Analyses Based on a Fast, High-Alpine Landslide

Round 1

Reviewer 1 Report

Please see the attached file for details.

Comments for author File: Comments.pdf

Author Response

Dear MDPI Section Managing Editor, dear Reviewer,

please see our Letter of Response to your review in the attachment.

 

Thank you and best wishes
Doris Hermle and on behalf of my co-authors

Author Response File: Author Response.pdf

Reviewer 2 Report

Dear authors,

this is an interesting manuscript and will certainly be a valuable contribution. I am suggesting "major revisions" only because I have a few concerns that go beyond minor errors and text edits.

My main concerns are:

• language: some of the sections are confusing or misleading; I added comments to the respective sections (see PDF). For example, the manuscript makes it sound like PC was not able to detect large lateral (coherent) displacements at all (e.g. in the conclusion) and that there is a ~20m cutoff - but this is a value that can be modified, to an inceased computational cost, i.e., this is not a fundamental limitation but a practical one. I suggest a rewording/modification of those sections.
• potential conflict of interest: this study uses software implemented in IRIS, which is a commercial tool developed by NHAZCA (if I am not mistaken). I realize that the underlying algorithms are published & accessible, but to a reader it might seem that the findings of this study could be biased (as one of the co-authors is with NHAZCA). Also, a reader might want to give your new methodology a try, which is not really possible currently (at least there is no clear guidance on how this could be done). It would be very useful if you could provide a brief statement, either in the acknowledgements or in the conflict of interest section.

Minor concerns are:

• figures: some of the figures are not very easy to read; a slightly increased font size could help
• open access idea: this concern is connected to one of the major concerns above; RS is an open access journal, but you do not publish your code and/or data. A reader might want to test your new methodology, i.e., it would be nice if you would provide the (deployment-ready) code in an open access repository along with the manuscript (best practice)

I hope you find my comments useful - and I look forward to see the revised version of the manuscript & your response to my comments!

Comments for author File: Comments.pdf

Author Response

Dear MDPI Section Managing Editor, dear Reviewer,

please see our Letter of Response to your review in the attachment.

 

Thank you and best wishes
Doris Hermle and on behalf of my co-authors

Author Response File: Author Response.pdf

Reviewer 3 Report

Peer review report 1 On “Performance testing of optical flow time series analyses based on a fast, high-alpine landslide”

1. Original Submission

1.1. Recommendation

Accept after Minor Revisions

2. Comments to Authors:

Manuscript ID: remotesensing-1511946

Type of manuscript: Article

Title: Performance testing of optical flow time series analyses based on a fast, high-alpine landslide

Authors: Doris Hermle, Michele Gaeta, Michael Krautblatter, Paolo Mazzanti and Markus Keuschnig

Overview and general recommendation:

The authors are trying to apply intensity-based motion analysis to generate ground motion for slope failure behaviour assessment, using two interesting algorithms, named phase correlation and dense inverse search.

A first comment reading carefully the paper is that the paper does fit the scope of the Special Issue of the journal (Remote Sensing for Natural Hazards Assessment and Control), and it could be of interest to the readership of the journal. In addition, the data and the results are presented appropriately and the conclusions are justified and supported by the results. However, there are some points that are missing or are not written appropriately in the whole paper. Therefore, I recommend minor revision. I explain my points in more detail below. Thus, to make this paper publishable, the authors need to respond to the following remarks.

2.1. Major comments:

Page 19, Lines: 590-591: Please explain more analytically why the results must be interpreted with caution.

Page 19, Lines: 617-618: The phrase “It is likely”, is an objective opinion which is based on data and experiments or is a subjective one? Please explain.

2.2. Minor comments:

1. Line 22: the word “were” must be replaced by the word “we”.
2. Line 170: the phrase “dense inverse search” should be accompanied by (DIS).
3. Line 633: the link mdpi.com/xxx/s1, is out of order. Nobody can access and read the supplementary material as authors suggest in line 266.

Comments for author File: Comments.pdf

Author Response

Dear MDPI Section Managing Editor, dear Reviewer,

please see our Letter of Response to your review in the attachment.

 

Thank you and best wishes
Doris Hermle and on behalf of my co-authors

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The paper is well revised

Author Response

Dear Section Managing Editor, dear Reviewer 1.

As you stated "The paper is well revised" we assume that a point-by-point response is not needed. Following the suggestion by Reviewer 2, we corrected some typos. You asked us to correct some as well.

 

Best wishes
Doris Hermle on behalf of the Co-Authors

Reviewer 2 Report

Dear authors,

thank you for considering my feedback. I would like to provide another set of minor comments.

• figures: the font size in some figures is still very small; you could make a reader's life easier if you would increase the font size
• language: I saw a few mino typos + punctuation errors; consider going through the manuscript one more time & tracking those down
• PC correlation "limit" in conclusion: I am still not very happy with the wording in the conclusion; consider adding one explanatory sentence (e.g. similar to what you wrote in the response letter)
• conflict of interest: Thank you for the additional explanations. I tried to locate the IRIS download request form on the specified website, but only found a general contact form, without any specific mention that I could request a trial version of the software via that contact form. Also, what happens after the trial period expires? I suggest adding a more detailed explanation to the paper on how to get a trial version and/or editing the website.

Thank you and best regards

Author Response

Dear Section Managing Editor,

 

please see the attachment for our point-by-point response to the reviewer’s comments.

 

Best
Doris Hermle

Author Response File: Author Response.pdf