## 3 Results  
The implementation of the various scanning methods in subsequent measurement campaigns as well as the application of two predefined measurement resolutions resulted in both the number of points and the average point density in the cloud being different. Both'manual' and 'automatic' classification processes led to a reduction in the number of points within the range from 0.01% to 2.7% (Table 1). Out of the eleven individual point clouds from 2010, nine were made in high resolution. However, a relatively small number of scan stations produced a total of 52,358,443 points in the DTM, while the average density of points for the AoI equaled 345 p/m\({}^{2}\). Moreover, both of these parameters were similar to those effectively recorded in the third measurement campaign (August 2013) when the average resolution was predefined for all eleven scan stations. The result was a total number of 45,207,502 points in the DTM and an average point density of 309 p/m\({}^{2}\) for the AoI. The DTM from July 2013 was a fragment of the model of the whole valley so in addition to the eleven scan stations  
Figure 3: A few object types of the off-ground points in the raw point cloud. Surfaces that were misinterpreted by the CSF represented only 3% of the AoI. Insofar as lowered areas slightly predominated within the range of surfaces in the raw point cloud, the lowered areas at threshold values (minLoD = 0.1 m) constituted as much as 79% of them (Table 2). The height change diagram shows that the average total thickness of difference was 0.23 m (\(\pm\) 0.10) with an average net thickness difference of \(-\)0.16 m (\(\pm\) 0.08) (Figure 3). All error areas were concentrated in the north-east part of the AoI and occurred within or at the boundaries of water surfaces (Figure 4). The oval shape of these areas indicated that the CSF algorithm omitted small concentrated groups or even single points that were found below the water level. In relation to the data from July 2013, the area of detected changes was identical to the AoI area for raw point clouds whereas it was only 0.2% of the AoI area for the threshold values (minLoD = 0.1 m) (Table 3). Among the areas misinterpreted by the CSF, the raw PC was slightly dominated by elevated areas (52%) while for threshold values it was the lowered areas that prevailed (95%) (Table 3). An analysis of the height change diagram showed that the averages of the total as well as the net thickness of difference were smaller than in 2010 and were from 0.16 m (\(\pm\) 0.10) to \(-\)0.15 m (\(\pm\) 0.09), respectively (Figure 4). As in 2010, all of the error areas were concentrated in the north-east of the AoI where they occupied similar locations and took on comparable shapes (Figure 5). In terms of the data from August 2013, the area of detected changes was less than 60% of the AoI area for raw point clouds whereas it was 0.1% of the AoI area for the threshold values (minLoD = 0.1 m), which was similar to the observations made in July (Table 4). Among the areas misinterpreted by the CSF, the raw PC was slightly dominated by elevated areas (52%) while for the threshold values, it was the lowered areas that prevailed (95%) (Table 4). An analysis of the height change diagram showed that the averages of the total and the net thickness of difference were similar to 2010 and were equal to 0.21 m (\(\pm\) 0.10) and \(-\)0.17 m (\(\pm\) 0.09), respectively (Figure 5). All of the error areas were concentrated on the right bank of the river in a section that was parallel to the storm dike. Lowered areas dominated there. Meanwhile, the largest area and height differences occurred coincidentally at the mouth of the river that flows into the fjord (Figure 6).