# Presentation: 754547

## NSDI Standards and Emerging International Geospatial Data Standards - Avoiding a Clash

- Richard Hogan
- U.S. Geological Survey
- Reston, Virginia
- June 23, 1998

- 703 648 5531

- rlhogan@usgs.gov

**Notes:**
Mr. Hogan is a Cartographer with the National Mapping Division of the U.S. Geological Survey.  He currently works on data policy and standards.  He has almost 20 years experience in standards development, over half of that in the international arena.
For the last three years, Mr. Hogan has been the Chair of the FGDC Standards Working Group.  He is currently serving his second term as International Representative for the National Committee for Information Technology Standards’ subcommittee for geographic information system standards (NCITS L1).  He has been a U.S. Delegate to the International Organization for Standardization’s (ISO) Technical Committee for Geographic information/Geomatics (TC 211) since its inaugural meeting in November 1994.
Mr. Hogan is currently serving as the USGS liaison to the National Association of Counties (NACo). He can be reached at either his USGS or NACo office.

National Association of Counties	U.S. Geological Survey
440 First Street NW		511 National Center
Washington, DC  20001		Reston, VA 20192
202 661 8808			703 648 5531
rhogan@naco.gov		rlhogan@usgs.gov

## The Geospatial Data Problem

- Data are hard to find
- Data are difficult to access
- Data are not current
- Data are undocumented
- Data are incomplete
- Data are not in the right format

**Notes:**
In 1992, Office of Management and Budget (OMB) Circular A-16 established the Federal Geographic Data Committee (FGDC) to coordinate the creation of a “national geospatial data resource” and the coordination of the geospatial data activities of the geospatial data producing agencies of the U.S. Federal government.

This action was the direct result of a series of studies and reports by federal advisory committees such as the Mapping Sciences Committee.  These reports concluded that in many cases Federal agencies were recollecting digital geospatial data held by other Federal agencies and that this apparent duplication of effort was encouraged by a number of problems related to the management of those data.

This list represents a simple, succinct statement of the “geospatial data problem.”

## NSDI Objectives

- Geospatial Data Standards
- Digital Geospatial Data Framework
- Digital Thematic Data
- National Geospatial Data Clearinghouse

**Notes:**
The FGDC has expanded on the idea of a “national geospatial data resource” first documented in Mapping Sciences Committee reports and the National Performance Review.  Through its work the concept of a National Spatial Data Infrastructure (NSDI) has emerged.

The objectives of the NSDI are simple, yet ambitious.  The four components of the NSDI concept are listed in no specific order of importance.  Standards are listed first because they are the focus of this presentation.

The objectives of the NSDI are data centric.  They focus on providing all sectors of America (public, private, commercial, and academic) the geospatial data needed for decision making related to a long list of social, political, and environmental problems.  These data are seen as a large, loosely connected distributed network that is constantly updated and revised with newer and more accurate data.  Framework is a concept for managing data within this distributed network.  The Clearinghouse is a concept for documenting, discovering, and assessing data within the network. 

Standards are the agreements among geospatial data producers, users, and system developers necessary to make the framework and clearinghouse concepts work.

## NSDI Standards

- Metadata - for documenting, finding & assessing data
- SDTS - for documenting, accessing & transferring data  (archive)
- Content standards  - for semantic definition
- Wetlands (classification)
- Vegetation (classification)
- Cadastral (data model)

**Notes:**
NSDI standards are seen as addressing one or more aspects of the geospatial data problem.  The largest number of standards activities within the FGDC to date has addressed the data semantics problem.

Although fewer in number, the FGDC standards associated with documenting, accessing, and transferring data are probably more universally recognized.  Standards like the Content Standard for Digital Geospatial Metadata and the Spatial Data Transfer Standard are applicable to a wide range of geospatial data.  These standards, especially the  metadata standard, are key to the development and implementation of the Clearinghouse.  Both standards, especially the SDTS, support digital archiving.

The matadata and transfer standards will also support the concept of framework through a mechanism called profiling.  However, other standards will be necessary to fully implement the framework.  These will consist of standards that define specific thematic data models and standards that define a specific framework data layer.

## Filling out the Matrix

**Notes:**
The need to document, discover, model, transfer and define geospatial data for a long list of application themes creates a matrix of standards which are needed to support those functions.  The matrix above is just a portion of the full FGDC/NSDI standards matrix.  It has been arbitrarily chosen as a tool to illustrate several points.

Metadata standard is generally applicable to all data themes
One or more semantic standards specific to a theme are being developed for each theme
Data models have not been widely defined, but will probably be needed by most framework themes
Voids are filled by de facto and non-standard solutions until an NSDI standard is identified.

## Filling out the Matrixby adopting

**Non-FGDC Developed Standards**

**Notes:**
The entire matrix of NSDI standards will not be developed by the FGDC.  In many instances standards developed for other purposes may be suitable for use without modification.  The use of Z39.50 standard developed by the National Information Standards Organization (NISO) as the standard for web-based metadata searches is an example.  This standard and a registered profile for geographic information element tags is being used to prtotype the NSDI Clearinghouse.

Z39.50 and the Geo profile is generally applicable to all themes
Z39.50 and Geo have been defined outside of the FGDC

## Filling out the Matrixby adapting

**General standards applicable to more than one theme**
**Profiles**

**Notes:**
Two standards developed by the FGDC (SDTS was developed, in part, by the Federal Coordinating Committee for Digital Cartography, the forerunner of FGDC) are meant to be general standards that are widely applicable to most FGDC data themes.  While this is generally true for Metadata, many users have expressed a desire to modify the standard for specific needs of a theme.  The recent revision of the Content Standard for Digital Geospatial Metadata makes this possible by providing for extensions and profiles of the base standard.  Two FGDC subcommittees have so adapted the standard through the development of specific profiles and a third has identified additional elements.
SDTS is also a general standard that is thought to be generally applicable to all FGDC themes.  Unlike the metadata standard, SDTS is implemented only through profiles so it has been included in the matrix only where a specific profile has been identified for that theme.
Both metadata and SDTS profiles are examples of adapting a standard.

Metadata standard is generally applicable to all data themes
Metadata profiles have been defined to further define metadata specific to that theme
SDTS is applicable only where a profile has been defined, since SDTS is implemented only through profiles

## ISO 15046 Scope

- Standardization in the field of digital geographic information.
- This work aims to establish a structured set of standards for information concerning objects or phenomena that are directly or indirectly associated with a location relative to the Earth.

**Notes:**
In 1994, the International Organization for Standardization (ISO) started a new Technical Committee (TC) for the development of digital geographic information standards.  This committee is designated ISO/TC 211.  The committee will develop a suite of related standards.  ISO has designated this suite as ISO 15046.  Each of the specifications developed by TC 211 will be designated as a part of ISO 15046.

This committee was created after work on digital geospatial data standards was well underway within the FGDC.  The FGDC metadata standard and the SDTS were already approved standards when ISO/TC 211 was created.

There existed - and there still exists - a potential for conflicting geospatial data standards to be developed at the international and FGDC levels.

## ISO 15046 Scope

- These standards may specify, for geographic information, methods, tools and services for data management (including definition and description), acquiring,  processing, analyzing, accessing, presenting and transferring such data in digital/electronic form between different users, systems and locations.

**Notes:**
The scope of ISO 15046 makes it clear that the objectives of this standardization effort and those of the FGDC in creating NSDI standards are very similar.

ISO/TC 211 does not explicitly address archiving. 

## ISO 15046 Scope

- This work shall link to appropriate standards for information technology and data where possible, and provide a framework for the development of sector-specific applications using geographic data.

**Notes:**
This is a significant part of the ISO 15046 scope statement.  It was introduced by the United States and is a direct response to industry’s desire to introduce geographic information system technology to applications well beyond the traditional ones of mapping and the “geo”-sciences.

This distinguishes the work of ISO/TC 211 from the geographic information standards work of the European Union which has pursued digital geographic information as a simple extension of digital mapping.

The U.S. is more concerned that ISO 15046 is closely related to general information technology standards - like Z39.50, SQL/MM, and ISO 11179 - while the Europeans are more interested in linking ISO 15046 to Computer Aided Design and Drafting standards.

## Projects within ISO/TC 211

**Projects within ISO/TC 211**

**WG 4**
**Services**

**WG 3**
** ****Data**
**Administration**

**WG 1**
**Framework**

**WG 5**
**Profiles**

**WG 2**
**Data**
**Models**

**(1) Reference  **
**     ****Model***
**(2) Overview**
**(3) Conceptual**
**     ****Schema Lang**
**(4) Terminology**
**(5) Conformance**
**     ****& Testing**
**(R) Imagery & **
**     ****Gridded Data**

**(7) Spatial **
**     ****Schema**
**(8) Temporal**
**      ****Schema***
**(9) Rules for**
**     ****Application**
**     ****Schema**
**(****20) Spatial**
**       ****Operators***

**(****10) Cataloging***
**(11) Ref by **
**       ****Coordinate**
**(12) Ref by **
**       ****Geographic**
**       ****Identifier**
**(13) Quality***
**(14) Quality **
**       ****Evaluation **
**       ****Procedure**
** **
**(15) ****Metadata***

**(16) Positioning**
**       ****Services***
**(17) Portrayal of**
**       ****Geographic**
**        ****Information**
**(18) Encoding**
**(19) Services**

**(6) Profiles**
**(R) Functional**
**      ****Standards**

**Notes:**
The U.S. leads Working Group 1 and the Reference Model project which defines the scope of the rest of the work.
Australia leads Working Group 2 which is defining the basic data models for geographic information.  The U.S. leads two of the 4 projects.  Australia has adopted the SDTS as an Australian standard and therefore supports the U.S. objectives with regard to that standard.
The United Kingdom leads Working Group 3 which is defining data administration standards.  The U.S. leads three of the six projects including the Metadata project.
Norway leads Working Group 4 which is defining geospatial service standards.  The U.S. does not have as much direct presence in this WG but the work is being closely tied to the U.S. industry dominated OpenGIS Consortium.
The Netherlands leads Working Group 5 which was initially led by Canada.  Canada still leads the Profile project which is critical to the U.S. because of our use of this technique for our own metadata and transfer standards.
.The ‘*’  indicates the project is led by the US.
 FGDC has an interest in all projects within the WG’s; however, a few of the projects are of special interest.
   WG3 Metadata has a direct 1 to 1 correlation with the FGDC Metadata standard.
   WG3 Cataloging also has a close correlation with FGDC Feature Registry std.
   WG5 Profiles correlate with the FGDC SDTS standard

## NSDI - ISO 15046 Relationships

**Data Documentation**
**(metadata)**
- FGDC CSDGM
-  nearly 1:1 with
- ISO 15046-15
- FGDC Content Standard for Digital Geospatial Metadata (FGDC-STD-001:1994) was used as the base document for WD 15046-15

**Notes:**
The FGDC metadata standardization effort is a good example of an effort that began well ahead of other efforts internationally and was made available to the international community as a starting point.

The FGDC standard was mature enough to be largely acceptable to the international community as a starting point.  Several significant improvements have been introduced through the the work of ISO/TC 211 and the FGDC continues to revise its standard to remain compatible.

When a mature specification exists in the U.S., it can be accepted by the international community.

## NSDI - ISO 15046 Relationships

**Data Transfer**
-  NCITS SDTS is highly compatible with relevant parts of ISO 15046, so much so that
- SDTS Topological Vector Profile
- could become the first
- registered profile of ISO 15046

**Notes:**
The SDTS was also a mature standard when the international standardization effort began.  But unlike the metadata situation, many other countries had transfer standards of their own.  To avoid a national competition for transfer standards ISO/TC 211 purposely omitted a project for transfer.

ISO 15046 will define standard components that can be combined into profiles that can be specialized for national use.  This approach is totally compatible with the approach developed for the SDTS.  SDTS is recognized within ISO/TC 211 as a model for modular standards and profiling of those standards.  

The project leader of the Profiles project of ISO/TC 211 would like to use an SDTS profile as a proof of concept.  Therefore, SDTS profiles may become the first registered profiles of ISO 15046.  This is vital because we use SDTS as a digital archive standard.

In this case, U.S. and FGDC interests are promoted by the acceptance of the concepts underlying U.S. standards that are, by themselves, not acceptable as international standards.

## NSDI - ISO 15046 Relationships

**Data Semantics**
-  ISO 15046-10 defines a standard methodology for creating geospatial feature catalogs
- it extends the basic feature model found in SDTS such that
- SDTS Part 2 is ISO 15046-10 compliant
- some FGDC content standards will need to be redefined to be compliant (Feature Registry Project)

**Notes:**
Much work has been done in the FGDC to define features and attributes for various NSDI themes of data.  This work has occurred, for the most part, in isolation from similar work, either in the FGDC or out.  As a result, there is only coincidental similarity among all the feature definition efforts.

This problem is not unique to the U.S.  It has occurred repeatedly all over the world.  To address this problem ISO/TC 211 created a project to define a standard methodology for creating geospatial feature and attribute definitions and the registries in which they are managed.

The ISO/TC 211 work is based on a very simple feature-attribute-attribute value model which has been widely used.  This basic model has been enhanced to support concepts such as relationships and behavior that are important in object oriented systems.

The feature-attribute-attribute value model was used in the development of the SDTS Part 2 and that model is now being used by the FGDC Feature Registry Project in an attempt to bring all feature definition and classification standards of the FGDC into a common format.  This is a retrofit effort that we would like to avoid, but is sometimes necessary to correct problems.

## The Strategy

- Promote NSDI standards as parts of  ISO-15046
- Influence development of key parts of  ISO-15046
- Link FGDC to ISO/TC 211

**Notes:**
The FGDC (and U.S.) strategy for harmonizing the international and NSDI standards efforts has been simple.

We have promoted the outright adoption of NSDI standards by ISO where that is appropriate.  This was appropriate in the case of metadata where the FGDC and ISO/TC 211 had nearly identical objectives for that standard.  This was not appropriate for the SDTS since ISO/TC 211 did not have a standards project specifically for transfer.

The U.S. has taken on the leadership of key ISO/TC 211 projects where that was possible.  When that was not possible, U.S. experts have taken active rolls in the work to assure that U.S. and FGDC interests are considered.

By active participation in the U.S. Technical Advisory Group to ISO/TC 211 - NCITS L1 - the FGDC has created a formal link to the work of ISO/TC 211.  FGDC is seeking to strengthen its link with NCITS L1 by considering the adoption of mutually agreed upon standards processes so that FGDC specifications can be parallel processed as American National and Federal standards.

## The Links

**Notes:**
International geographic information standards is the domain of the International Organization for Standardization’s (ISO) Technical Committee 211 (TC211); Geographic information/Geomatics.
American national geographic information standards is the domain of the American National Standards Institute’s (ANSI) accredited subcommittee the National Committee for Information Technology Standards (NCITS) and its subgroup L1; Geographic Information Systems Standards.
U.S. Federal geographic information standards and the Executive charge to coordinate all NSDI activities, including standards, is the domain of the Federal Geographic Data Committee (FGDC).

The formal link between the international geographic information standards body (ISO/TC 211) and the U.S. national geographic information standards body (NCITS L1) is that NCITS L1 is the U.S. Technical Advisory Group (TAG) designated by ANSI to represent the U.S. on ISO/TC 211.  The FGDC is a voting member of NCITS L1.

However, the real link among these groups that makes the coordination happen is a small cadre of U.S. experts that participate at all three levels for specific standards activities that are important to the U.S.

## Key Metadata Persons

- Rick Pearsall - USGS
- Dave Danko - NIMA
- Leslie Godwin - Census Bureau
- Norm Andersen - Lockheed-Martin

**Notes:**
These are the key individuals who are involved the geospatial metadata standardization.  Each one is involved at all three levels; FGDC, NCITS, and ISO.  Each of these individuals has a different role at each level, but overall they work as a team to create not only  a workable metadata standard but an environment that is conducive to metadata standardization for data producers, data users, and system manufacturers.

Mr. Pearsall leads the metadata effort at the FGDC level.
Mr. Danko leads the metadata effort at the ISO level.
Ms. Godwin leads the definition of quality elemets which ISO has chosen to give special consideration.  She does so at both the NCITS and ISO levels.
Mr. Andersen brings commercial expertise to the effort at all three levels.

Note that Lockheed-Martin, a commercial entity, is active even at the FGDC level of standardization.  The FGDC encourages non-federal participation in the development of NSDI standards.  Membership on the FGDC’s Standards Working Group is open to anyone with a material interest.

## Collision Avoidance

- Be aware of other activities
- Link processes
- Introduce and defend key concepts
- Reverse engineer when necessary

**Notes:**
In any standards effort, it is what you don’t know that is going to hurt you.  Collisions cannot be avoided when you are not aware of what is out there that might be an obstacle.
Once the other key efforts have been identified, they should be linked.  It is especially important to link international, national and regional efforts.
When U.S. and international efforts go in completely different directions, collisions can sometimes still be avoided by reverse engineering existing specifications.  We like to avoid this, but it is important to recognize when it can be done to head off conflicts.

FGDC - NCITS L1 - ISO/TC 211 standards activities have been linked
Key U.S. interests have been introduced into the international work for fair consideration
FGDC existing specifications are being revised to remain compliant with emerging ISO specifications

## Best Practices

-   Adopt existing standards
-   Adapt existing standards
-   Link domain specific standards to                          general IT standards
-   Get involved in international technical work as soon as possible
-   Avoid “end runs”

**Notes:**
A few more bits of advice.

  Adopt existing standards whenever possible.  This is always a wise choice.  Minor problems should be ignored.
  Adapt general standards to your needs if it is not possible to outright adopt another standard.
  Know what the domain of your standards effort is and stick to it.  Then link your domain specific standards to general IT standards by adopting and adapting those general standards as appropriate.
  Get involved in any international efforts within your domain as soon as possible.  National efforts, no matter how good, can be overtaken by international efforts, so be an international player.
  Don’t use international standardization efforts as a way to get around other legitimate national efforts.  These end runs, no matter how successful at the time, usually end up being disasters since no national consensus is ever established.