ABSTRACT
Global Navigational Satellite System (GNSS) combined with Geographic Information System (GIS) are fundamental tools for the georeferencing of cartography from diverse origins and periods that allows us to link thematic information of maps or images with the real position in the field. With this paper, we seek to define a methodology for the use of old cartography in order to obtaining georeferenced information for use in spatial and multi-temporal studies. For this work, several points have been positioned all around the bay of Cadiz, which were identified on the 1789 map and positioned with GPS techniques. They have been used as control points so they can be inserted in a GIS layer for the georeferencing and adjustment of the old map. The points were referred to the ETRS89 Terrestrial Reference System and the positioning Leica Geodetic GPS receivers model 1200, were used. For GPS geo-processing, Leica Geomatic Office software and ArcGis Software for GIS and Remote Sensing. Applying these combined techniques, we have detected the urban changes in the area, but the most important are changes in the coastline and in littoral zone configuration. The most important conclusions of the study are that the use of the combined technique of GNSS systems, GIS and Remote Sensing is an excellent tool for spatial and multi-temporal analysis. They provide us a satisfying result in the detection of the changes, which are due to urban growth and changes in sea level with local and global environmental changes.
