While the theory and implementation of geographic information systems (GIS) have a history of more than 50 years, the development of dedicated educational tools and applications in this field is more recent. This paper presents a free and open source software (FOSS) approach for education in the geospatial disciplines, which has been used over the last 20 years at two Italian universities. The motivations behind the choice of FOSS are discussed with respect to software availability and development, as well as educational material licensing. Following this philosophy, a wide range of educational tools have been developed, covering topics from numerical cartography and GIS principles to the specifics regarding different systems for the management and analysis of spatial data. Various courses have been implemented for diverse recipients, ranging from professional training workshops to PhD courses. Feedback from the students of those courses provides an invaluable assessment of the effectiveness of the approach, supplying at the same time directions for further improvement. Finally, lessons learned after 20 years are discussed, highlighting how the management of educational materials can be difficult even with a very open approach to licensing. Overall, the use of free and open source software for geospatial (FOSS4G) science provides a clear advantage over other approaches, not only simplifying software and data management, but also ensuring that all of the information related to system design and implementation is available.

Turbidity is a visual property of water, related to the presence of suspended particles in waters. This parameter is measured in different water quality monitoring programmes as it can determine negative environmental effects both on the biotic and abiotic marine ecosystem. Traditional methods, e.g., in situ monitoring, offer high accuracy but provide sparse information in space and time. On the other hand, Earth Observation (EO) techniques have the potential to provide a comprehensive, fast and inexpensive monitoring system to observe the biophysical and biochemical conditions of water bodies. In the present work, a method for seawater turbidity retrieval from Sentinel-2 multispectral optical images, freely available within the EU Copernicus programme, is presented. The study explores different atmospheric correction methods available in open source software (QGIS, GRASS GIS and SNAP), in order to convert Level-1C (L1C) Top-Of-Atmosphere (TOA) images to Level-2A (L2A) Bottom-Of-Atmosphere (BOA), when the latter is not directly available. Once the proper method for atmospheric correction was identified and applied, the correlation between the in situ dataset and the individual bands known to be most sensitive to water turbidity, i.e., blue (B2), green (B3), red (B4) and near infrared (B8 and B8A) bands, were investigated and a linear regression model between selected band values and turbidity was identified.

Integrated remote sensing techniques, such as photogrammetry from unmanned aerial vehicles (UAV), mobile laser scanners (MLS) and multibeam echosounders (MBES), are particularly effective in detecting and measuring coastal and seabed features and their modifications over time (4D analysis) induced by sea storms. In fact, these techniques allow the production of very high-resolution 3D models, with a continuum between above and below sea level. The present research is focused on the area of Portosole Marina (Sanremo, Western Liguria), affected by a severe sea storm in October 2018 and the following restoration. Two integrated 3D surveys were performed in February 2019 and in November 2019, obtaining accurate and reliable high-definition digital surface models (DSMs) in both emerged and submerged areas. The comparison between the two surveys highlighted volumetric changes in the seabed induced by the sea storm and the effects of a temporary worksite on the emerged and submerged breakwater. In particular, a total deficit of sediments of about 5000 m³ caused an average lowering of about 4 cm over the entire area, concurring with the breakwater instability. This study aims to contribute to the understanding of coastal system resilience within ongoing global climate changes, that is, increasing the intensity of extreme events in the Mediterranean area.

The conservation of Cultural Heritage depends on the availability of means and resources and, consequently, on the possibility to make effective operations of data acquisition. In facts, on the one hand the creation of data repositories allows the description of the present state-of-art, in order to preserve the testimonial value and to permit the fruition. On the other hand, data acquisition grants a metrical knowledge, which is particularly useful for a direct restoration of the surveyed objects, through the analysis of their 3D digital models. In the last decades, the continuous increase and improvement of 3D survey techniques and of tools for the geometric and digital data management have represented a great support to the development of documentary activities. In particular, Photogrammetry is a survey technique highly appropriate in the creation of data repositories in the field of Cultural Heritage, thanks to its advantages of cheapness, flexibility, speed, and the opportunity to ensure the operators’ safety in hazardous areas too. In order to obtain a complete documentation, the high precision of the on-site operations must be coupled with an effective post-processing phase. Hence, a comparison among some of the photogrammetric software currently available was performed by the authors, with a particular attention to the workflow completeness and the final products quality.

The present work is part of a series of activities involving different skills, in order to explore and document in detail one of the most visited caves in Liguria Region. In this context, in addition to speleologists, geologists, videographers, the geomatic expertise has also been involved to carry out a laser scanner survey, in order to produce a three-dimensional model of the two more easily accessible rooms of the cave. The survey was carried out using Z+F IMAGER® 5010 instrument and the post processing operations related to registration of point clouds have been made with Z+F LaserControl®. Subsequently, two different free and open source software were used: MeshLab, to merge the point clouds and to obtain the final mesh, and CloudCompare, to make filtering on the previous results and to extract sections.