MOVING OBJECTS AND SPATIAL DATA SOURCES

Abstract

Moving object is a well-established concept in geographic information system (GIS) science. It is an entity whose spatial position or extent changes continuously over time. Some examples are cars, animals and deforested regions. Nowadays, there is a growing demand for GIS tools that are able to handle and analyze moving objects. Most existing spatial file formats (e.g. KML and GML) and database systems (e.g. PostGIS) represent spatial and temporal information using structures and types predefined in specifications written by the International Organization for Standardization (ISO) and the Open Geospatial Consortium (OGC). However, in these specifications, there is nothing about moving object representation in data files or databases. Each data producer adopts its own format to do it. Therefore, this work proposes an interoperable strategy to translate spatial and temporal information stored in different data sources into moving object trajectories for further analyses. The proposed approach is based on the processing of an additional metadata file that describes how moving objects are stored in a particular data source. Grounded on this strategy, we have built a new software module for moving object analysis in a geographical library called TerraLib. This module architecture is also described in this paper.