The authors presents a software to process satellite images using image correlation and show a few examples. 

Without entering into the details of the study, which seems good at a quick reading, I think that it is off topic for NHESS, but it should be submitted to more appropriate journals that focus on software like, e.g., Geoscientific Instrumentation, Methods and Data Systems or Computers & Geoscience.

Regards

The authors present TerraTrack: an open-source, cloud-based processing chain that computes the displacement of slow-moving landslides. They discuss the performance of the different implemented methods through synthetic data and three landslide study sites. The codes are already available on GitHub and seem well documented. The tool implements different methods, offering users flexibility. This is a really nice effort of open-science, which could be usefull for landslides study, and teaching of remote sensing, and possibly more.

The paper is very well written and the quality of the analysis is good. However, I think the quality of the paper could be improved by addressing a couple of points.

1. The author could add more explanations and references on the different methods they are implementing.
2. Some choices should be discussed. For now you are not masking shadows : what’s could be the impact?
3. The analysis of subpixel refinement method is bit hard to follow... You mention the benchmark analysis in the case of Slumgullion, but without giving the results of this analysis. Simarly, in the discussion you summarize the results on Slumgullion, then give as recommandation the PCC (without giving a recommandation on the subpixel refinement). Then, you analyse the results on the benchmark to discuss subpixel refinement performances again.  It could be clearer to add a small section to present the resultts on synthetic data before the landslides cases. It will help you to explain why you selected the PCC and 4 subpixel refinement methods for Slumgullion. At the end of Slumgullion, you could say that you are selecting os3 for the other landslides. In the discussion, you could discuss in this order : 1) your recommandation for the Feature Tracking algorithm 2) your recommandation for the subpixel refinement method, using the benchmark and Slumgullion case.
4. In the abstract you wrote « We validated the workflow on cases with independent displacement measurements ». I was expecting comparison with GNSS or InSAR data. However, even in section 4.2 you are not comparing InSAR and FT results on the points which are in common... Please consider either modifying the abstract or adding more analysis..

See attached file for specific comments.