METADATA REQUIREMENT FOR GIS: A CANADIAN EXPERIENCE gc 
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Gordon Plunkett = 
GeoAccess Division, Geomatics Canada, Natural Resources Canada (n 
615 Booth Street, Ottawa, Ontario, KIA OE9 th 
Ph: (613) 992-0389; Fx: (613) 952-0916 Tc 
E-Mail: gordon.plunkett(? geocan.nrcan.gc.ca an 
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Commission II, Working Group 3 & 
Ge 
KEYWORDS: GIS, Database, Standards, Archiving, Organization. Tt 
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ABSTRACT: an 
During the development of Geographic Information Systems (GIS) projects, there is usually a requirement to perform data 
exchanges between different agencies or at least between different systems. Various distinct kinds of data are required by ca 
most GIS application projects in order to complete the project successfully. With the growth in the use of GIS and in the ini 
voracious data needs of GIS systems, there is a great requirement for common and consistent descriptions of the diversified su 
kinds of data that can be used in GIS. Information describing data is often called metadata or data about data. Because of (a 
the diverse nature and multiplicity of data formats and standards, a need for some type of metadata standardization is nu 
required. Within Canada, a working group of the Canadian General Standards Board has developed a standard that can be de 
used for the description of various digital georeferenced data sets. This metadata once collected can be used for the 
creation of data set directories, which can in turn be used by users for locating the various data sets required by their In! 
application. This paper describes the new Canadian metadata standard and several methods that are being used for the av. 
dissemination and maintenance of this metadata. Some of this work is being performed by the GeoAccess Division of an 
Geomatics Canada under the auspices of the Inter-Agency Committee on Geomatics (IACG) within the Canadian federal du 
government. The paper describes earlier work performed by Roger Tomlinson for the IACG, including both the data wa 
collection phase and the data distribution phase. Also the new Canadian standard for the collection of data describing nk 
digital georeferenced data sets is documented. rel 
material regarding the data set. The metadata standard should i 
1. INTRODUCTION contain sufficient information for a researcher or manager to eni 
GIS application project managers will generally spend over decide if they are interested in obtaining more information on gd 
the data set or perhaps the data set itself. va 
half of their project resources on data related issues. During 
the development of GIS projects, data related issues such as inf 
  
data location, data conversion and data storage can become In the past, metadata was collected and then a directory was de 
messy and expensive tasks. Most GIS projects require various constructed that would allow users to peruse the catalog for thr 
different kinds of data in order to complete the project information regarding their requirements. This previous work 
successfully. The following list outlines many of the most in data directories led to the development of data schemas in 
common types of data required for typical GIS application commercial DBMS for storage of the metadata. The metadata 
projects. was then provided to users on diskette in this commercial 
: format which the user would then load into his own DBMS or Th 
+ Base cartographic data (most often derived from se directly. Users could then perform searches, produce De 
topographic maps) with good spatial accuracy; reports, locate specific data set etc. 
: : ; : CG 
e Thematic data that is derived or conceived from human 19 
interpretation; : Wil ors ; : 
p t ; : ; This method of data distribution was adequate at the time, but be 
e Spatial statistical data that is derived mathematically : : n 
: it suffered from several problems in the data revision area. The dat 
from some type of data collection or census; : ; A 
ar ; : problem included the fact that users who received a diskette sta 
e Remote Sensing imagery data that is or can easily be ; : : ; 
s were not automatically sent a revised diskette because it was pri 
geocoded to the base cartographic data; and : : ; d 
« "Other kinds or data that Ts collected or vortravet ira GIs an expensive task to deliver updated diskettes to all the users. at 
P y ! In addition, it was difficult for the data producing agencies to 
update their data easily and this needed to be done at a central The 
Project managers must often decide on whether to purchase or 
obtain data sets without ever seeing the data set. This means 
that a clear concise description of the data set must be 
available for the manager to make his decision. A standard for 
depicting this type of information describing digital 
georeferenced data sets should contain fields for the 
identification of the data set; contact persons; a description of 
the data set; a description of the coverage (including spatial, 
vertical and time); data revision; data set size; data collection 
details; data quality; the availability of the data set; the medias 
available; the structure of the data set and any reference 
310 
site. So the result was a good metadata product, but it was 
difficult to maintain and disseminate. However, the solution to 
many of these problems is to develop a capability using the 
Internet to allow users to perform both data search and update 
functions. 
2. INTER-AGENCY COMMITTEE ON GEOMATICS 
The Inter-Agency Committee on Geomatics (IACG) was 
formed in 1988 from members of various Canadian federal 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B2. Vienna 1996