FOSS GIS

In the field of Cultural Heritage (CH) there exists a growing interest in multimedia applications based on 3D information systems. Several proposals have been made to implement 3D data models describing archaeological and monumental  heritage in their own 3D environment. In this context, 3D GIS models, using the integration of 3D models with geographic
and multimedia information, might be an interesting research field: they might bridge the gap between the geographic scale
and the architectural scale, allowing users not only to visualise models, but also to make queries getting data from them. Currently, the real prototypes of 3D GIS are just a few and mainly regarding the urban environment. Archaeological and historical sites, instead, have been represented and analysed by other systems (e.g. 3D semantic models). This paper illustrates a framework developed by GISLab to obtain a 3D information system shareable on the network and able to access to geographic and multimedia information on CH. The application produced is composed of: a 2D GIS project (by QGIS), a 3D model (by Blender), a “Cultural Heritage oriented” database
(by PostgreSQL+PostGIS) and a PDF format as a graphic  interface. The 3D model is embedded in the 3D PDF and associated with semantic information stored in an RDBMS
(Relational DataBase Management System). The application’s workflow includes the following steps: the data acquisition; the analysis of the building system, its decomposition in parts and elements and its classification based on hierarchical and relational criteria; the database project; the implementation of a 2D GIS (regional-scale analysis) on the whole geographical context surrounding the building; the implementation of the 3D model of the monument (architectural-scale analysis); the implementation of the GUI (Graphic User Interface) based on the PDF format; the 3D model’s export from the modeling software to the 3D PDF format; the connection between the database and the 3D model via ODBC (Open DataBase Connectivity); the web publishing of the 3D information system
(WebGIS for the regional-scale, linked through a hyperlink to the 3D PDF for the architectural scale). Within the 3D PDF application the 3D visualisation of an architectural or archaeological object is associated with a graphical interaction with the model: JavaScript functions allow users to get data of the architectural object from the DB associated with the 3D model. The 3D model embedded in the PDF is measurable and navigable. It can be rotated, enlarged, and displayed in axonometric and perspective views as well as in solid, wireframe, transparent and textured modes. It also allows users to change the scene lighting, to get sections of the 3D model, and to visualise just a few parts of it (e.g. just some
chronological phases or constructive elements that are loaded each on a different layer). The system described has been  implemented almost entirely using GFOSS software. It has
been tested on the Arab-Norman “sollazzi” (extra-urban palaces of the Norman kings built in the 12th century in natural  contexts) in Palermo (spatial scale). A particular focus has been made on the Castle of Maredolce (architectural scale).

Purchasing of licensed GIS software would always be costly, while failure to
acquire a valid license poses a hindrance in an organization, especially in the
public sector. This scenario has led to alternative transition to open source software
(OSS). However, to implement OSS technology, it requires a specific appraisal
process to evaluate the criteria of needs of an agency. This is important to ensure
the assessment process is more valid and convincing. A research associated with
this requirement has been conducted to evaluate the users’ needs when they opt for
OS GIS. This study aims at determining the weights of each assessment criteria of
OS GIS in handling geospatial data at the district and land office. As the
assessment process involves several criteria, an Analytical Hierarchy Process
(AHP) is used to get the accepted response for each assessment.

OSM2LULC is a software package developed to automatically convert OpenStreetMap (OSM) data into Land Use Land Cover (LULC) maps using Free and Open Source Software for Geospatial (FOSS4G) tools. It needs to be highly efficient given the increasing detail of OSM data and the need to apply it to large extent regions. In this article, a comparison between the implementation of OSM2LULC in different available GIS platforms is made using both vector and raster data structures, which resulted in different versions. A description of the differences of each version is made and, to assess their performance, they were applied to four different study areas with different characteristics, in terms of available OSM data and area size. The performance of each version was evaluated taking into account: the overall processing time required to obtain LULC maps; and differences in the results obtained when different data structures (vector and raster) were used. Results showed that the adoption of a ...