Metadata is 'data about data'. It is information that describe the data on a product. It covers all the questions on the data such as who, what, when, where, why and how. Metadata can be viewed as a conveyor of information about the goods. The parable of 'metadata' is like a label/advertisement on a product. One will not know about a product if there is no metadata. Each question will be answered if the metadata is complete.
In the context of geospatial information, metadata is important in providing information and convenience to the users inevaluating the relevancy of the data. It enables the users to understand the capabilities and limitation of data as well as to assess the usefulness of a dataset .
Diagram 1 : Component of MyGDI
Metadata is a main component in the development of Spatial Data Infrasturcture (SDI). This metadata is also known as the Geospatial Metadata, which is describe geospatial information to be shared. It is not only limited to data, but it also includes information about GIS applications, research reports, development of geospatial information and services.
The objective of geospatial metadata, is to provide information regarding geospatial information produced for the users to evaluate information. The benefits of metadata publishing is promoting the availability of geospatial information.With a complete metadata, we can find a detailed on the original source of geospatial data and a change of lineage on the data. It is a structured means of describing the content, sources, condition, quality and other characteristics of the acquired data.
The purpose of publishing metadata are:
Provides geospatial information appearing in government and private agencies;
Avoid duplication of data or services from various agencies;
Geospatial information allow users to identify the required; and
Providing legal protection in the event of abuse of geospatial information
Selection element metadata catalog based on ISO 19115-1: 2014 Geographic Information - Metadata - Part 1 - Fundamentals. These documents can be obtained or purchased directly through SIRIM Berhad.
Elements contained in the catalog metadata consists of:
Information of data provider
Reference system information
Data quality and others
Diagram 2: MS ISO 19115: 2003
Through the implementation of MyGDI, the important of metadata has been identified. Malaysian Metadata Standard Template (MMS) developed and adopted to facilitate geospatial data providers to record their information. It also to facilitate the users to obtain the required geospatial information. List or metadata catalogue is contained in MyGDI Explorer.
Diagram 3 : Metadata Template Screenshots (MMS) through MyGDI Explorer.
Links that may interest you:
The Implementation of Use Malaysian Standard for Geographic Information / Geomatics - Feature and Attribute Codes (MS1759);
Malaysian Metadata Standard (MMS);
Standardization of Geographical Names in the Geographic Names Database & National gazetteer (PDNG).