|The authors resubmitted a revised version of the manuscript entitled "The Potential of Smartstone Probes in Landslide Experiments: How to Read Motion Data". The article has improved, and I have only a few minor comments on its present version. However, regarding the article type, I still have a slightly different opinion than the authors which I outline in some more detail below. To conclude, I still think as previously stated that the authors present an interesting measurement system. However, since the manuscript is, in my opinion, focusing on the presentation of experimental and theoretical methods and techniques which are relevant for scientific investigations, I recommend publication of the manuscript as a technical note (please see below for further details). I consider this as "technical corrections", as the measurement system is definitely of interest for the community.|
Please accept my apologies that I used the terminology "brief communication" instead of "technical note" in my last review, because manuscripts of this type "should be short (a few pages only)". I would like to thank the editor for catching this in his decision letter. Maybe the editor can accept the manuscript as a technical note with overlength. Otherwise, the article would have to be shortened, which could be done by omitting many details of the analyses and focusing on a compact presentation of the main features. However, if the editor feels that the manuscript fulfills the requirements of a research paper (as indicated in the decision letter), I do not object, as my recommendation reflects my personal opinion.
Before presenting my detailed comments on the manuscript, I see the need to justify my recommendation regarding the article type more clearly. The following statement is rather lengthy as I directly quote statements from the HESS-website and from the authors' rebuttal letter.
I noted from the rebuttal letter that the authors claim that the article should be published as a research paper, which they are completely entitled to. Please note that my recommendation is based on the definitions of the HESS-article types which I studied when reviewing the manuscript. According to the website, "research articles report on original research which clearly advances our understanding of hydrological processes and systems, and/or their role in water resources management and Earth system functioning as detailed in the journal's aims and scope". In my opinion, the manuscript does not fulfill this definition (see my comments in the initial review). Instead, in my opinion the manuscript fulfills the requirements for technical notes, which "report new developments, significant advances, and novel aspects of experimental and theoretical methods and techniques which are relevant for scientific investigations within the journal scope". In fact, the authors claim in the rebuttal letter that they "identified an important methodological gap in studying landslide motion processes", "documented a significant methodological improvement", and "outlined future improvements". In this context, my previous review-comments had nothing to do with "good scientific practice" as partly stressed by the authors in the rebuttal letter, but solely with my interpretation of the HESS-website article type definitions.
Having given these statements, I noted that a paper has just been published in which version 2.1 of the sensor has been used [Ravindra, G.H.R., Gronz, O., Dost, B., Sigtryggsdóttir, F.G. (2020). Description of failure mechanism in placed riprap on steep slope with unsupported toe using smartstone probes. Engineering Structures 221, 111038, doi:10.1016/j.engstruct.2020.111038]. It is unfortunate that the present manuscript presents version 2.0 when a new version of the sensor has already been used. Moreover, I was surprised that that the article of Santos et al. (2019) (for the reference, see the rebuttal letter) has not been cited in the manuscript.
Detailed comments of minor nature:
Abstract: I still think that the abstract is too detailed, as it contains specific results for a special experiment. Therefore, the numbers presented at L16-18 could be omitted and this could be phrased more generally.
L14: Please check use of tense (compared to the previous sentence).
L41: Please check the sentence starting in this line.
L130: I still think that such a sentence is not adequate here and should be located at the end of the paper in the conclusions or outlook.
L207: This has been mentioned before (e.g., L75 and L95).
L297: But isn't the pebble most of the time "somewhat tilted"?
L314: Replace "Now, we want to" by, e.g. In the following, the movement is investigated with respect to..."
L525: I still infer that the question why e.g. Kalman filtering or Markov-localization has not been done in the study.
L578: Redundant information (see L69).