## 6 Conclusions  
Our study on Corvara landslide highlighted some opportunities and limitations for PS-MTI-based landslide monitoring on the slope scale. The spatial and temporal variations, as well as the magnitude of displacements make the Corvara landslide an ideal but challenging laboratory for testing technologies, equipment and methods. Our PS-MTI-based analyses have been able to detect the overall trends of displacements. The best results were achieved for points that exhibited linear and relatively slow movements (i.e., in relation to the temporal resolution of the image acquisitions and the wavelength of the sensor used). Problems of loss of coherence arose with the monitoring of fast and sudden accelerations, as well as movements mainly directed along the satellite track (north-south). Assessed errors were found to be in an acceptable range for many end-user applications. Thereby, PS-MTI represents a useful method for monitoring ground deformations of low criticality, e.g., slow and deep-seated landslides and rockslides. Still, additional periodic monitoring techniques are mandatory for validation and to reach the high level of reliability requested by public administrations. Anyway, given the usefulness of PS-MTI for landslide monitoring, on the regional but also on the slope scale, it can be expected that the number of such applications will increase in the future. In particular, the recently launched Sentinel-1 satellite constellation offers interesting prospects for such endeavors. The C-band sensors used for Sentinel-1 as well as the high temporal resolution of image acquisitions facilitate measurement of faster and larger ground displacements than CSK. Moreover, due to the fact that the Sentinels are operated with an open data policy, the delivery of images can be expected to be reliable and timely, therefore the attractiveness of MTI can be expected to increase. Near real-time applications or even early warning systems, however, cannot be expected in the near future; in fact, although MTI software is steadily becoming more convenient to use, the processing remains time-consuming and expertise-demanding. For monitoring the Corvara landslide, a change to Sentinel-1-based monitoring requires a modification of the CRs installed on the landslide. Currently, the monitoring system is being upgraded to meet the requirements, and the new CRs will have an increased side length. Additional research on the Corvara landslides is being carried out within the Lemonade project (see [[http://lemonade.mountainresearch.at](http://lemonade.mountainresearch.at)]([http://lemonade.mountainresearch.at](http://lemonade.mountainresearch.at))), in which a wider range of ground-based (e.g., DGPS), close range (e.g., terrestrial laser scanning, ground-based photogrammetry) and remote sensing techniques (e.g., MTI, OT, multiple aperture interferometry and possibly IG) are applied and integrated. CSK images were provided by the Italian Spatial Agency (Product COSMO-SkyMed(r) ASI (2014 and 2015)--All rights reserved). We would like to acknowledge the kind support of our research activities by the municipality of Corvara and the Ski Carosello Corvara. We would also like to thank everyone who was involved in fieldwork, [PERSON], [PERSON], as well as [PERSON], [PERSON] (SARmap SA, Purasca) and [PERSON] (EURAC research, Bolzano, Italy) for their support in SAR image processing. A special thanks goes to [PERSON] from the Geodesy Office of the Bolzano Province working at the maintenance of the Permanent GPS Regional Network. [PERSON] analyzed data, interpreted results, prepared the manuscript and managed its revision. [PERSON] contributed to the result analyses and paper writing. [PERSON] contributed to the design of the study, the organization of GPS surveys, the elaboration of GPS data, the error analysis, the interpretation of the results, and the preparation of the manuscript. [PERSON] performed interferometric SAR processing and analyses. [PERSON] contributed to the interferometric processing and to the error analysis.