Monitoring a Landslide with High Accuracy by Total Station: A DTM-Based Model to Correct for the Atmospheric Effects

Abstract

For the monitoring of large landslides, total stations equipped with an Electronic Distance Meter (EDM) are widely used. To obtain the atmospheric parameters, required along the line of sight of every measure, the data collected by a weather station close to the instrument are usually adopted. Even after these corrections, the results obtained in the monitoring of areas with complex topography don't reach the accuracies theoretically attainable by the high-end instruments. The article proposes a method for removing the errors due to the influence of microclimate on the measurements obtained by a high-end EDM, in order to get the maximum accuracy obtainable from such instruments. The method is based on an atmospheric model, set up by using the climatic data and a digital terrain model (DTM) of the landslide area. The methodology has been applied to a landslide in southern Italy. Over 38,000 distances, acquired for each monitored point, were used. The results demonstrate the effectiveness of the method: the standard deviations of the distances after their correction, show a reduction, ranging from 20% to 50%, with respect to the most diffused procedures; furthermore, the obtained accuracy equals the one declared by the manufacturer of the instrument for measurements in optimal conditions.

TLS for Dynamic Measurement of the Elastic Line of Bridges

“…Their main limit is the need to measure one target at a time, so they cannot be used to dynamically monitor multiple points; (2) Total robotic stations are characterized by high precision and measurement automation. Thanks to the capability to transfer data even via the Internet and be managed remotely, they are used to monitor slopes and large structures [8,9]. The sampling frequency up to 7 Hz allows its use for dynamic measurements [10,11], but it is not possible to track more points at the same time; (3) GNSS satellite surveying is often used for tall buildings and large span bridges [12][13][14].…”

“…The high S/N ratio, typical of these devices, strongly influences the results of dynamic tests; (7) Currently, the measurement of deflections by using laser beams is widespread. Some systems for the measurement of deflections and displacements with the use of laser beams are described in [22,23]; (8) An effective methodology for measuring displacements of large structures is offered by Ground-Based Synthetic Aperture Radar (GB-SAR).Used in RAR mode (Real Aperture Radar) it allows measurements of vibration frequency and displacements associated with dynamic loads. In SAR mode (Synthetic Aperture Radar) the instrument is mounted on a slide and allows to obtain the mapping of the area investigated at different times and to get the deflection of each point.…”

A comparison of multi temporal interferometry techniques for landslide susceptibility assessment in urban area: an example on stigliano (MT), a town of Southern of Italy

“…Surface deformations like landslide can be monitored with a variety of sensors (Cal o et al 2012). Current methods are, for instance, airborne and terrestrial laser scanning (ALS and TLS), (Lichun et al 2008;Monserrat and Crosetto 2008;Mallet and Bretar 2009;Kasperski et al 2010) prism measurements with robotic total stations (RTS) (Artese and Perrelli 2018), GNSS measurements (Bovenga et al 2013), and ground or satellite-based differential interferometric synthetic aperture radar (DInSAR) (Tarchi et al 2003;Cascini et al 2009;Lowry et al 2013). All these techniques are classified as 'Remote Sensing', which refers to the science aimed at collecting Earth Observations (EO) by using non-contact methods.…”

Spatial Prediction Models for Landslide Activity Mapping Using Vegetation Anomalies

“…However, this method is an active sensor and the data acquisition depend on various factor such as natural illumination, foreshortening, layover effects, atmosphere propagation effects, and vegetation decorrelation in forested terrain (Rott, 2009;Scaioni, Longoni, Melillo, & Papini, 2014). Besides that, the techniques of geomatics also widely used for landslide activity analysis (Artese & Perrelli, 2018).…”