Reliability of DTMS Obtained With Mobile Fast Surveys Techniques

Abstract

Abstract. The contribution addresses the issue of the integrated survey aimed at three-dimensional modeling for the documentation of different types of terrain through the analysis of two case studies located in the province of Pavia - Italy. The techniques of aerial photogrammetric acquisition SfM (UAVs), Terrestrial Laser Scanner (TLS) and Mobile (MLS) are now consolidated and widely used, managing to meet the needs of documentation of land levelling, monitoring, and analysis of landslide volumes. The two case studies present difficulties due to a strong inclination of the land and extensive presence of vegetation in the first case and to a strong presence of agricultural canalizations in the second case. The data processing phase focused on the comparison between MLS and close-range photogrammetry, while the acquisitions from TLS were used as control data. This acquisition method allows avoiding the process of approximation and reconstruction of the DTM under the vegetation, ensuring the correctness of the data relating to the ground course. The database allows the generation of highly reliable DTMs using specific point cloud modeling and processing software. Fast survey instruments are ideal in large areas or in hilly areas where sub-vertical sections and covered by vegetation are often present, difficult to detect only with close-range photogrammetry.

Digital Strategies to Enhance Cultural Heritage Routes: From Integrated Survey to Digital Twins of Different European Architectural Scenarios

“…This strategy ensured the acquisition of accurate spatial data and photographic information, which was crucial for structuring and validating the geometric database [22] (Figure 4). Furthermore, the use of rapid-survey instrumentation was necessary to understand the extent of the three routes and to ensure the replicability of the method [23], both in terms of timing and the type of product obtained. The archives obtained with these tools and other data (3D panoramas, high-resolution landscape images, etc.)…”

“…Furthermore, the use of rapid-survey instrumentation was necessary to understand the extent of the three routes and to ensure the replicability of the method [23], both in terms of timing and the type of product obtained. The archives obtained with these tools and other data (3D panoramas, high-resolution landscape images, etc.)…”

Hbim Modelling for the Architectural Valorisation via a Maintenance Digital Eco-System

“…Notably, they allow speeding up acquisition procedures for documentation at an urban scale, making it possible to map different urban contexts, thus overcoming the difficulties linked to reduced accessibility or to magnitudes that cannot be covered within an adequate timeframe by the established 3D surveying procedures, i.e., Terrestrial Laser Scanners (TLS) (Dell'Amico, 2021). Thanks to the SLAM algorithm and the integrated IMU (Inertial Measurement Unit) sensor, both wearable (Hess and Ferreyra, 2021;Sammartano et al, 2021) and handheld (La Placa and Doria, 2022;Parrinello and La Placa, 2021) MLS solutions have proven to be suitable for the documentation and valorisation of ever-changing natural and historical environments, without needing the support of a global navigation satellite system (GNSS) (Barba et al, 2021). Furthermore, knowing that the quality of mobile acquisitions is primarily based on how data are acquired, many precautions can be implemented to maximise the results, such as previous inspection, walking slow (0.5 m/s), good coverage and high-resolution data (Guida et al, 2021).…”

“…In particular, with regard to data acquisition procedures, an integrated acquisition method that employs SLAM mobile technology and TLS laser tools was tested, with the aim of verifying on a spatially complex architecture a simplification and consequent optimisation of the Scan-to-BIM operational paradigm. Regarding sustainability, above all in terms of time, the use of state-of-the-art mobile laser scanners (MLS) supplied by Leica Geosystems allowed a halving of work times while still guaranteeing a degree of metric reliability and data quality (La Placa and Doria, 2022) sufficient to achieve the pre-set Level of Development. It only required the integration of photographic data in the case of detailed modelling, comparable to an as-built, or for the correct decoding of material finishes.…”

Lidar Imms vs Handheld Multicamera System: A Stress-Test in a Mountain Trailpath

“…This trend has also accelerated due to improved sensors and positioning algorithms that gradually increase the output accuracy. In the last years, they have made possible the development of many commercial wearable devices that can be successfully used in indoor environments (Indoor Mobile Mapping Systems, IMMSs) (Otero et al, 2020), or, more generally, in those areas where GNSS signal is not available, like densely vegetated areas (La Placa & Doria, 2022), underground sites (D'Agostino et al, 2022) and urban canyons (Blaser et al, 2020). Especially in GNSS denied areas, Simultaneous Localisation And Mapping (SLAM) algorithms, at the base of LiDAR IMMSs, allow for the simultaneous estimation of the sensor trajectory and the creation of a map of the environment.…”