The Brazilian Army steps towards SDI interoperability through OGC standards

Contributed by: 
Captain Emerson Magnus de A. Xavier, Cartographic Engineer - Brazilian Army Geographic Service (DSG)

The Brazilian Army Geographic Service (DSG) has been dealing with geospatial interoperability issues for years. Brazil is the world's fifth largest country in area, with more than 8 million km². Its large size presents numerous challenges related to mapping and map maintenance. The existing geospatial data were produced by public and private companies, with distinct standards and procedures, in different periods. The integration of these data is the major challenge for the Brazilian Spatial Data Infrastructure (INDE), and the OGC open standards play an important role in meeting this goal.

The principal access point of the Geographic Service of the Brazilian Army (DSG) INDE node is the Brazilian Army Geoportal. This system is built using several OGC standards, including the OGC Web Map Service (WMS), Web Feature Service (WFS), Web Coverage Service (WCS), and Catalog Services – Web (CSW) interface standards, and also the GeoXACML encoding standard. Implementations of WMS are used for visualization; implementations of WFS and WCS provide data query and download; and implementations of CSW are used for metadata publishing and discovery. GeoXACML enables the use of georeferenced access policies to data and services.

These service standards (WMS, WFS, WCS, and CSW) are adopted by the Brazilian Executive Committee for Electronic Government through its interoperability framework, which is called Electronic Government Interoperability Standards (e-PING).

The Geoportal uses the TerraLib library to implement the geospatial Web services. TerraLib is an open-source GIS library built up by the Brazilian National Institute for Space Research (INPE). The DSG is one of the leading contributors in the development of Brazil's Web-GIS applications. The data are managed in PostgreSQL/PostGIS spatial databases.

Currently, almost 9000 geospatial products are available in the Geoportal, including about 5000 raster and 1800 vector topographic maps, all with their corresponding metadata. The Geoportal also offers the first results of the Amazon Radiography Project. These data comprise digital elevation models and orthoimages at five-meter resolution, made from airborne radar technology in a region known as the "Cartographic Blank of Amazon".

DSG is one of the Brazilian SDI's technological leaders. Our large collection of geospatial products are made available on the Internet to profit the Brazilian society in the large. To reach this objective, we make wide use of OGC standards to provide the required interoperability.