GIS heading for EXPRESS-based standards

The Norwegian Mapping Authority (Statens Kartverk) is one of several national and international institutions working on the development of a new EXPRESS based ISO standard within the GIS sector, known as ISO/TC211. <7p>

Enormous amounts of data

Senior engineer Einar Kjesbu of NMA is an active participant in the international ISO/TC211 project. He explains some of the challenges facing the GIS sector:

"We often start collecting data for map production by analyzing aerial photographs. The resulting data are then linked to existing map information and together they constitute enormous amounts of data.

"Today, most countries have their national standards for geodata, for instance the format we use in Norway is called SOSI. Now, parts of that standard have been described in EXPRESS to be compliant with ISO TC211."

Kjesbu continues: "It is our goal for the international standardizing projects that geographical data can be transferred between all kinds of GIS products and platforms. It should be possible to use the same basic data to generate maps for various users and purposes, such as forestry, road authorities, power plants, and municipal planning."

European standards in two years

Both the international standardizing committee ISO/TC211 and its European equivalent CEN/TC287 have been working with GIS. Although ISO/TC211 decided to use the results of CEN/TC287 as the basis of their work, each committee has influenced the other. And they have both decided to use EXPRESS as the standard information modeling language.

Most of the CEN/TC287 sub-standards have already achieved status as "ENV" ó guiding European standard. In two or three years they must be fully approved as "EN" ó European standard. Otherwise, they will be canceled.

"I count on the ISO standards also being finished by then," says Kjesbu optimistically.

"No-one will be forced to use the future standards. However, ISO/TC211 has started to co-operate closely with the Open GIS Consortium to ensure that the standards are implemented by system suppliers. Hopefully, CEN will adopt these as officially binding ó with EN status."

Better data quality with EXPRESS Data Manager

Einar Kjesbu and NMA use EXPRESS Data Manager and EDMvisualExpress in their work.

"The systems from EPM Technology come as integrated products, which is a clear benefit," says Kjesbu.

"I am most satisfied with these tools. Using EDMvisualExpress makes it possible for me to draw models on several levels.

I can move the entities to EXPRESS Data Manager, thus achieving a better compilation than otherwise possible. As a result, I discover more errors now that would have been ignored before."

GIS standardization efforts

ISO/TC211 ó the Technical Committee for describing standards in the field of geographic information/geomatics ó consists of five so-called Working Groups. 26 countries participate and 15 are observers. GIS professionals meet at regular intervals to present and evaluate projects. The sixth meeting was held in Canada in March 1998.

Olaf Østensen of the Norwegian Mapping Authority is the chairman of ISO TC211.

ISO/TC211 has recognized the development of a number of external standards that will influence the establishment of more general ISO/TC211 base standards. ISO/TC211 has the mandate to bring together these emerging international, transnational and regional standards under the umbrella of a comprehensive series of ISO standards.

Fore more information, go to http://www.isotc211.org/

CEN ó the European Committee for Standardization ó operates on a pan-European basis as opposed to ISO which is world-wide. CEN has the same goals as ISO and works on a GIS standardization project known as CEN/TC287. Both organizations have decided to use EXPRESS data modeling language with the STEP standardforming the basis of their work.

More information at http://forum.afnor.fr/afnor/ENGLISH/index.htm

OGC ó the Open GIS Consortium, Inc. ó aims to obtain full compatibility between all GIS software. Last year, OGC announced that they were starting a close co-operation with ISO/TC211. The goal is to converge and match their respective work plans to avoid duplicate or divergent work.

More information at http://www.opengis.org

CEN = European Committee for Standardization
GIS = Geographic Information Systems
ISO = International Organization for Standardization
NMA = Norwegian Mapping Authority
OGC = Open GIS Consortium
TC = Technical Committee