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Description
During 2001/2002, the Norwegian Meteorological Institute (METNO) implemented a web based tool (MetaMod) for searching data archived under the NoSerC project (http://noserc.met.no/). This tool was adapted for DAMOCLES database search in 2006/2007. The web interface and the overall functionality of the tool were very much improved during the DAMOCLES development, and just a small part of the original code base has remained unchanged. Other projects at METNO have also contributed to the development process. The software is now named METAMOD2, to distinguish it from the original MetaMod tool that is still occasionally maintained.
METAMOD 2.x is a portal solution providing Discovery, Access and Retrieve functionality for scientific projects along with tools for metadata handling etc.
The purpose of the METAMOD2 software is twofold:
- To manage a data repository containing scientific data sets.
- To keep a database containing metadata that describes the data sets in the data repository, as well as other data sets found in external data repositories (not managed by METAMOD2 software).
As additional projects were seen to benefit from using METAMOD2 software, a need for making the software independent of a single project emerged. This was obtained by organizing the software in different modules, and by separating all project specific aspects into a configuration file. METAMOD2 now comprise the following modules:
| METAMODBASE | Database and corresponding administrative tools. |
|---|---|
| METAMODSEARCH | Web based search facility. |
| METAMODUPLOAD | Web based upload facility for data files. |
| METAMODQUEST | Web based questionnaire for registering metadata. |
The configuration file describes an actual implementation of a web application based on METAMOD2 software. First of all, the file lists which of the four modules that are used in the application. Any combination of the four modules is allowed. If the METAMODBASE module is not a part of an application, the configuration file must reference another METAMOD2 application that uses the METAMODBASE module. In this way, several applications may share the same database.
The software is implemented on a Linux system with Apache web server. PHP is used to implement dynamic web content, and Perl is used to implement tasks not directly involving web content generation. The database is based on PostgreSQL. Metadata elements use controlled vocabularies from GCMD and CF1.0 as well as WMO keywords. Tools for extraction of metadata from NetCDF/CF files are part of METAMODUPLOAD. Access to the actual datasets is provided through HTTP, FTP, OpeNDAP. Use of THREDDS Data Server (OpeNDAP and OGC WCS) is being examined currently as well as metadata exchange using OAI-PMH.