## 4 Results  
As mentioned in paragraph 2, according to the proposed approach, a preprocessing step was performed: Firstly, the R-Index map (Figure 5a) has been generated to investigate the presence of radar targets along \"P.R. 264\". In particular, having acquired satellite images along ascending orbit, visibility of the interested area in such geometry has been analyzed. Such analysis was generated starting from a \(10\times 10\) m DTM and geometric parameters of satellite acquisition (incidence angle: 30\({}^{\circ}\) and orbit angle: 10\({}^{\circ}\)). Figure 4: Official landslide inventory (**a**) and state of activity (**b**) maps interacting with buffer zone along P.R. 264 (modified from Hydro-geomorphological Setting Plan of South Campania River Basin Authority, 2012). As it is possible to note in R-Index maps, a good visibility and thus a high density of scatterers could be obtained by ascending images. Therefore, along most of the linear infrastructure, the R-index value is higher than 0.4, thus confirming a good detectable geometry. Moreover, the map of \"C\" correction factor (Figure 5b), representing the percentage of target real movements which can be detected by interferometric products, has been obtained as a function of DTM, satellite acquisition parameters above-mentioned, and topographic parameters (terrain slope and aspect). It is worthwhile to highlight that, along the P.R. 264 linear infrastructure, the factor C shows positive values and most of them range from 0.7 to 1.0. Subsequently, in order to characterize ground movement kinematics, 52 Very High Resolution (VHR) (StripMap, up to 3 m resolution) COSMO-SkyMed ascending images, acquired in time-span 25 January 2012-01 January 2015, have been processed by means of the 'SUBSOFT' software. The SUBSOFT processor has been developed by the Remote Sensing Lab of the Universitat Politecnica de Catalunya of Barcelona, Spain, using the CPT-TSC approach. To detect scatterers with high phase quality, only the interferograms whose image pairs had spatial and temporal baselines lower than fixed values, have been selected. In detail, 250 m and 250 days, respectively, have been fixed. Furthermore, owing to the need to have a sufficient number of targets covering the entire study area, and to display at the same time a good phase standard deviation of approximately 20\({}^{\circ}\), corresponding to a displacement standard deviation of 1.5 mm, a threshold value of coherence equal to 0.75 has been set. As a result, mean displacement velocity, annual displacement velocity, and displacement time series of identified scatterers, measured along the line of sight (LoS), have been obtained. The real slope displacement of each target, which can be considered as a quantitative evaluation of the projection of VLOS along the local slope is calculated by the ratio between 'LoS' value and the \"C\" correction factor calculated for the corresponding pixel. The high spatial resolution of COSMO-SkyMed data (\(3\times 3\) m) and the high density of points of measurement regarded allows to reduce the level of uncertainties and error (equal to about \(\pm\) 1.5 mm/yr for linear velocity and about \(\pm\) 4.0 mm for single displacement). The main characteristics of the used SAR data, C factor values, and V-SLOPE (velocity along the slope) range measurements are shown in Table 1. It is important to highlight that, to detect intensity of  
Figure 5: R-Index (**a**) and “C” factor (**b**) maps for ascending track. ground instability phenomena in the surrounding areas and induced deformations of road surface, a 100 m buffer-distance along the linear infrastructure has been created, and inside it a fishnet grid with pixel size of \(10\times 10\) m has been implemented. Only scatterers selected within such area have been considered: About 1876 targets have been identified by CPT processing with an average of more than 600 PS/km\({}^{2}\).