Landslide Deformation Extraction from Terrestrial Laser Scanning Data with Weighted Least Squares Regularization Iteration Solution

Round 1

Reviewer 1 Report

This manuscript proposed a new method for landslide deformation extraction from TLS data. The triangular pyramid target is developed to overcome the shortcoming of spherical target. In case of inconvenient traffic, this paper also proposes a new scheme of data acquisition and registration based on total station rear view orientation. The weighted least square regularization iterative solution can effectively reduce the ill-condition of the model. It is interesting for readers and suitable for publication in remote sensing. Hence, it is recommended to be published after a minor revision.

Q1: The ordinate and abscissa of Fig.3 are not very clear, please correct them.

Q2: The registration accuracy is used as evaluation index in the analysis of experimental results. The definition of registration accuracy is not described. The author should give the definition of registration accuracy.

Q3: Total station is used for data acquisition, but the technical parameters of total station is not described. The author should add the parameters of total station

Q4: There are some grammatical or spelling errors in the manuscript, which should be revised carefully. For example, " The Biezang Landslide NO.3 is shown in figure 18. " should be replaced by " The Biezang landslide NO.3 is shown in figure 18. ",P12,line 8.

Author Response

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Reviewer 2 Report

Review of the manuscript ID remotesensing-1740038 entitled ‘Landslide Deformation Extraction from Terrestrial Laser Scanning Data with Weighted Least Squares Regularization iteration solution’

The authors present an interesting case-study on improving the efficiency of landslide deformation extraction from terrestrial laser scanning data. While the topic and method itself seem interesting and fit the topic of a remote sensing journal, the structure of the paper and the experiment itself raise my doubts. The first major problem is the conception of this work. It is a typical methodological paper based on an experiment and based on data acquired in the field by the Authors. In the paper, the Authors focus on the conceptual assumptions, description of the experiment conducted and the results. However, the manuscript was submitted as a scientific article. In this type of paper, discussion cannot be missing, whereas in the submitted manuscript it is only in the subtitle of the chapter '3. Experimental Results and Discussion'. Despite this caption, there is no real discussion here. What we have here is a characterization and location of the study area, technical data of the equipment, a description of the data processing steps and an attempt to comment on the results obtained. What is lacking here, however, is discussion. To the extent that there are any discussion threads, the authors 'discuss' only their own findings. There is not a single reference to the results of other works! This is unacceptable in this type of paper. Moreover, the description of the methodology occurs in both Chapter 2 Methodology and Chapter 3 Experimental Results and Discussion. It should be organized in such a way that there is a separate description of the current state of knowledge and research as well as theoretical assumptions and the purpose of the paper (introduction); the course of the experiment (measurements, technical data) and the stages of data processing (methodology); the description of results (results); and the discussion in which the authors discuss their achievements in relation to the results of other authors (going beyond the studies of authors from China, who dominate the list of references). The second major problem is basing the concept on a single study. Many databases with raw TLS measurements (including landslides) from other regions of the world are available from which the proposed research procedure can be verified. One example is unconvincing. I suggest the authors to reach for these data and verify the method on the basis of other landslides. At this point it is worth raising the issue of terminology. The title landslide (or is it rockfall?) is depicted only in fig. 11. Here we see a mechanically undercut (by a road) slope and the title 'landslide' above its edge. In fact, panels b, c and d, which were supposed to show the landslide, show very little. They are too small to judge whether it is indeed a landslide. Even if it is, it's not very spectacular. I suggest taking a UAV photo, of the entire landform (landslide), so that there is no doubt as to its origin. If I'm already on terminology, for what reason Landslide Deformation is written with a capital letter? What do the authors mean by 'DTM deference'? Is it about DEM of Difference (DoD)? Some abbreviations are not well developed like GNSS (Global Satellite Navigation System); should be GNSS, Global Navigation Satellite Systems. What do the authors mean by ' Bursa model'. No citation here . Are they referring to the Bursa-Wolf model (e.g. Deakin, R.E. (2006). A Note on the Bursa-Wolf and Molodensky-Badekas Transformations. School of Mathematical and GeospatialSciences, RMIT University, 1-21) ? In Table 4, the hardware data is not very correct. I suggest 'Scan range' description as >0.4m>1km (or from 0.4m to 1 km) and instead of 'Accuracy of noise' it should be 'Range of noise'. By the way, you should provide the source of this data below caption and in references. In summary, although the topic is interesting and well suited to remote sensing. This text is underdeveloped in terms of concept and structure. It needs serious changes.

Author Response

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Round 2

Reviewer 2 Report

The manuscript has been revised and missing information has been completed. The authors have also added new figures to improve the manuscript. I recommend acceptance of the manuscript in its present form.