WASCAL Data Discovery Portal Wiki

The WASCAL Data Discovery Portal (WDDP)1 is used to access and search information on all kinds of data generated by or related to WASCAL. It queries the CMC and other metadata catalogues according to certain user specific search conditions, displays the results and allows, if permitted, a download of the data. You can obtain date from the portal in (basically) three steps:

1. Perform a query
2. Select the data set(s) your are interested in
3. Display metadata and download the data

The WDDP provides methods to search for sensors, maps, reports, publications and any other research related digital resource, which in the following we call “data” for reasons of simplification. The information about available data is organized in a metadata catalogue (metadata = data about data). A metadata record provides information on different aspects of a digital resource. The metadata catalogue entries are linked either to external data sources or to the WASCAL research project, where the data is stored and can be retrieved from. There are several possible ways to query the metadata catalogue, which are described in the following sections.

Figure 2 shows the basic layout of the main page of the WASCAL Data Discovery Portal with its one main user interfaces. The user is enabled to perform a search by topic, get the results and include the interactive map layers (if provided by a metadata set) into the map viewer on one screen. How that works is described in the following sections of the handbook. The different sections (1-4) of the page are:

1. Navigation panel to other Services like Data Provision, Information, Feedback and Help (see ).
2. Quick search by free text (see chapter 4.2)
3. Search to data by map selection
4. “Browse by Topic” section to explore the content of the database by performing topical searches in the metadata catalogue (see …).
5. Each image in section 3 refers to a specific topic. By clicking the picture, a predefined query will be triggered and the result will be displayed in a new page.
6. In this section you can get a brief introduction about the Data Discovery Portal and find latest news.

After a search query is triggered, a second page will be invoked (see Figure 3). A browseable map viewer shows the geographical reference of the data sets (if provided), which allows you to take a look at the positions of the stations of your interest. By selecting of a station you have access to further metadata details of this station. The map viewer uses numbered marker symbols; time series data from sensor networks are numbered by letters (A, B, …), whereas “static” data sets are numbered by digits (1, 2, …). In the lower part of the screen a paginated list of the queried data sets with the same enumeration as in the map viewer is shown. Finally, the left part of the screen provides possibilities to extend or restrict the current query or initiate new data queries, such as specifying new “What”, “When” or “Where” conditions (see …). Details:

1. A map viewer application shows the geographical reference of the data.
2. The search result is shown as a list containing the title and (if selected) the abstract of the data
3. Clicking on one of the marker symbols provides more information on the data set(s).
4. Search results are shown in pages, which can be scrolled here.
5. “View Metadata” button offers a relative compact summary of metadata with more details (see …)
6. Advanced Search panel to perform extended search with additional options such as “When?”, “Where?”, “What?” (see …)

Clicking on the „View Metadata“ button opens a third page. A detail view to the metadata will be displayed, allowing the user to investigate the details of this metadata such as keywords, contact, lineage, online resources etc. Figure 4 gives an example with the details:

1. Geographic reference (location or bounding box) of the data set (if any) in an interactive map. If an online resource refers to a Web Map Service (WMS) layer, the content of this layer is shown.
2. Responsible organization and/or person for this data set.
3. Online Resources attached to the metadata set with additional functions: “follow link to resource”, “add WMS layer to map”, “download resource” etc.