The second year of terrestrial laser scanning has been completed successfully for the site in Corvara (IT). Now it is time for data processing and looking into change patterns in the 3D point clouds.
The LEMONADE team contributed to EGU 2017 (Vienna Austria) with two presentations about landslide monitoring using close-range and remote sensing techniques… have a look:
Rutzinger, M., Zieher, T., Pfeiffer, J., Schlögel, R., Darvishi, M., Toschi, I., Remondino, F. (2017): Evaluating synergy effects of combined close-range and remote sensing techniques for the monitoring of a deep-seated landslide (Schmirn, Austria). In: Geophysical Abstracts. Vienna, Austria, Vol. 19 (EGU2017-6393-3). Download poster
Schlögel, R., Darvishi, M., Cuozzo, G., Kofler, C., Rutzinger, M., Zieher, T., Toschi, I., Remondino, F. (2017): Sentinel-1 and ground-based sensors for a continuous monitoring of the Corvara landslide kinematic (South Tirol, Italy). Vol. 19 (EGU2017-12913). Talk
The LEMONADE project released a video explaining why data integration helps for better understanding of landslides…
A second survey campaign in Fortebuso was realized in October 2016 over an over of approximately 150 x 100 m. The work included a UAV field campaign coupled with Total Station and GNSS survey in order to measure the position of several targets both inside and outside the landslide. The image block includes 232 images with a mean GSD of about 8 mm. Among the surveyed ground points, 6 points were included in the photogrammetric processing as GCPs whereas 6 points were used as cjeck points (CPs) to evaluate orientation accuracy. RMS errors on CPs resulted 8 mm (x), 11 mm (y) and 7 mm (z, vertical). The dense image matching extracted a point cloud with a mean spatial resolution at GSD level (around 8 mm). With the support of the Geological Service, the areas supposed to be “active” according to the periodic monitoring activities were identified. Then vegetation (trees) was filtered out and the cloud better aligned with the output of the previous campaign (June) by applying an ICP algorithm on the stable points of the area. Further analyses are now in progress to understand landslide movements.
Find more pictures from the Fortebuso test site in the gallery.
The LEMONADE project has been presented at the Young Professionals Conference on Remote Sensing hosted by the IEEE Geoscience and Remote Sensing Society (IEEE-GRSS) and by the German Aerospace Center (DLR) in Oberpfaffenhofen (Germany). Mehdi Darvishi talked about first project results giving a presentation about 3D Reconstruction of a Large Landslide from UAV-Based Imagery.
In the frame of the LEMONADE project, EURAC – Applied for Remote Sensing Institute performed the UAV flight campaign on the 23.06.2016 aiming to produce high resolution orthomosaics, 3D point clouds as well as Digital Surface and Terrain Models.
The UAV was flying exactly the same area, considered as the most active part of the Corvara landslide (i.e. 13 hectares on air) covered in 2015. The original flight plan consists of five different flights, each of them 200 m long, 80 m wide and 60 m height.
Unfortunately, during the flight campaign of this year we faced technical difficulties because we were not able to transmit the flight plans into the automatic flight controller mounted on the UAV (control system that follows a pre-programmed GPS point route). Since one single field campaign takes a lot of effort, organization and time, the pilots decided to flight in manual mode, i.e. controlling elevation, orientation and speed during each flight. The general consideration that we agreed was to keep (i) the height of 60 m and (ii) the straight lines with the support of one observer standing in the opposite side of the landslide. The digital camera was configured to acquire one image every 2 seconds according to a flight speed of 5 m/s what gave us some images every 10 m approximately. In order to retrieve reliable results and decrease the effect of the manual flight mode, four flights were done using the same orientation and one in the orthogonal orientation.
We were able to collect 1190 images that were preliminary pre-processed to confirm the overlapping coverage. This task consisted on filtering images, converting images from raw to tiff (using Rawterapee software), assigning position to each image, and finally doing the first processing step on Pix4D software (e.g. keypoints and coarse cloud point generation and first derived digital surface model).
Check out the preliminary programme of GeoTirol2016. The session Geo-environmental monitoring using remote- and close-range-sensing techniques chaired by the LEMONADE project will consist of the following oral presentations:
Sterk, H.P. et al.: Progress in digital mapping of shallow mass movements by using a combination of orthophotos, LiDAR- and UAV-derived information.
Mayr, A. et al.: Extraction of eroded areas on mountain grassland from orthophotos at different scales
Lechner, V. et al.: Detecting and quantifying debris flow-related geomorphologic changes in an alpine catchment using LiDAR and photogrammetry data
Fey, C. et al.: Long range terrestrial laser scanning (TLS) for the deformation monitoring of alpine slopes
Beiranvand Pour, A.: Structural geology and topographic mapping of Kelantan river basin using PALSAR-2 remote sensing data for high risk area delineation
Eisank, C. et al.: Semi-automated landslide mapping based on multispectral satellite imagery: two Austrian case studies from the Land@Slide project
First TLS scans were acquired in the upper part of the Reissenschuh landslide. A Riegl VZ-6000 scanner was used to derive point clouds from two view points with in total more than 175 million points. This corresponds to a mean point density of 120 pts/sqm.
The FBK team, supported by the Geological Service and the Civil Protection Department of the Autonomous Province of Trento, conducted the first data acquisition campaign at the Fortebuso landslide. A DJI S1000+ octocopter equipped with a Sony Alpha 6000 digital camera acquired images at sub-cm resolution (GSD) during three flights. Total station and GPS surveys were carried out in order to measure targets both inside and outside the landslide. The photogrammetrically derived dense point cloud contains approximately 100 mil points and it’s now used for geological analyses and monitoring purposes.
Start reading at Provincia Autonoma di Trento – Ufficio Stampa (5.4.2016) and Fondazione Bruno Kessler (5.4.2016).