CLOSE RANGE DIGITAL PHOTOGRAMMETRY TECHNIQUES APPLIED TO LANDSLIDES MONITORING
This paper deals about the use of non metric reflex digital cameras in landslide monitoring and the analysis of landscape evolution from comparison of present digital photographs and old digitized analogue metric terrestrial photographs. The methodology has been improved in a test area (a slope along a road with instability processes in southern Spain) where terrain failures have been documented in the last ten years. Several photogrammetric techniques were checked as well as combination of both convergent (for calibration and densification) and stereoscopic (for DTM generation) networks. Considerations about the use of terrestrial LIDAR and a comparative example are also made. This paper is included in a wider research project carried out in Northern and Southern Spain for study landslides. This research project (MAPMUT: The improvement of susceptibility analysis by means of useful digital models of the terrain geometry), aims with an improvement of susceptibility maps using high quality input information.
USE OF UAS IN A HIGH MOUNTAIN LANDSCAPE: THE CASE OF GRAN SOMMETTA ROCK GLACIER (AO)
Abstract. Photogrammetry has been used since long time to periodically control the evolution of landslides, either from aerial images as well as from ground. Landslides control and monitoring systems face a large variety of cases and situations: in hardly accessible environments, like glacial areas and high mountain locations, it is not simple finding a survey method and a measurement control system, which are capable to reliably assess, with low costs, the expected displacement and its accuracy. For this reason, the behaviour of these events presents the geologists and the surveyor each time with different challenges. The use of UAS (Unmanned Aerial System) represents, in this context, a recent and valid option to perform the data acquisition both in safety and quickly, avoiding hazards and risks for the operators while at the same time containing the costs. The paper presents an innovative monitoring system based on UAS-photogrammetry, GNSS survey and DSM change detection techniques to evaluate the Gran Sommetta rock glacier surface movements over the period 2012-2014. Since 2012, the surface movements of the glacier are monitored by ARPAVdA (a regional environmental protection agency) as a case study for the impact of climate change on high-mountain infrastructures. In such scenarios, in fact, a low-cost monitoring activity can provide important data to improve our knowledge about glacier dynamics connected to climate changes and to prevent risks in anthropic Alps areas. To evaluate the displacements of the rock glacier different techniques were proposed: the most reliable uses the orthophoto of the area and rely on a manual identification of corresponding features performed by a trained operator. To further limit the costs and improve the density of displacement information two automatic procedures were developed as well.
Comparison of a Radiometric Procedure with Conventional Methods for Identification of Neisseria
A radiometric procedure was compared with the conventional cystine tryptic agar (CTA) sugar fermentation method for identification of Neisseria species. Four different ATCC cultures of Neisseria were identified by both procedures with identical results. The only difference noted was that the radiometric procedure required 3 h for completion, whereas the conventional CTA sugar method required overnight incubation. The radiometric procedure was also compared with the fluorescent antibody (FA) and CTA methods for identification of Neisseria gonorrhoeae. The organisms examined were gram-negative, oxidase-positive diplococci isolated from 49 clinical specimens sent to the laboratory for bacteriological analysis. Results obtained by both CTA and FA procedures were comparable. However, the radioisotope method appeared to be superior to the other two methods in that only one isolate identified as positive by both the CTA and FA methods was not identified radiometrically, whereas four isolates positive by the radiometric method were not identified by the other two procedures. Thus, a total of seven more positive identifications were made radiometrically than by either of the two other methods. All positive identifications were confirmed by a reference laboratory. These results indicate that the radiometric procedure is more rapid and reliable as compared with both the CTA and direct FA methods and, thus, may serve as a valuable addition to the methodology available for diagnostic microbiology.