Enhancing Discoverability in PDS: A New Findability-Focused Approach to PDS4 Metadata.

The Planetary Data System (PDS) Small Bodies Node (SBN) is actively working to advance the FAIR (Findable, Accessible, Interoperable, and Reusable) characteristics of our data.  While current PDS4 models are well-suited for describing observational data, there is a need to better support the discovery of these datasets, especially higher-level, or “integrated” data sets.

 

High-level data sets, or “integrated data” sets, are typically the result of extensive data analysis and contain some of the most science-rich information.  These products usually are produced by combining multiple observations and even can be from multiple observing platforms or missions.  They include products such as digital terrain models, mosaic images, geologic maps, spectral feature maps, thermal maps, and crater databases.  Though rich in scientific value, these products can be difficult to discover in the current PDS4 system because a lack metadata that contains many of the parameters most scientists would typically use.

 

To address this need, SBN is developing a new "Findability" metadata dictionary designed to enrich PDS4 labels with attributes better suited for integrated products.  Most of the metadata currently being archived for PDS4 is limited and focused on describing the data for use.  There are only a few fields that are well suited for search.  This new dictionary emphasizes more abstract and science-driven parameters.  To maximize the finability of the data, we seek to identify a wide suite of characteristics to describe the data.  Our dictionary includes 21 different parameters that reflect different ways to think about the data to expand the conceptual coverage and aid discovery.

 

These new metadata parameters range within four broad categories of data

1 - What science discipline, including the technique of how the data is generated

2 - Characterization of the object of the data

3 - Typical subcategories of how the data is generally thought of

4 - What is the research context (i.e. what was the goal of the research)

 

By enabling the addition of these keywords and categories to dataset metadata, this new dictionary makes it possible to search and filter data using criteria that align more closely with how scientists frame their research questions.

We have begun building tools and web interfaces to aid in the generation of the data.  We provide a list of options to the data providers in order to quickly classify their data with the same questions that the eventual users would be working with.  Figures 1 and 2 illustrate examples of the type of user-friendly interface that this metadata enrichment could support.

Finally and most importantly, this work directly supports FAIR principles by enabling both human users and automated tools to more effectively identify and access the data results.  Once the PDS has this enhanced suite of metadata, then a greatly expanded suite of searches can be done.  This would result in a wide range of terms not only providing results from search queries, but these terms can be used to filter the results.  This would greatly reduce the friction in locating valuable higher-level datasets, creating a PDS archive that better serves the evolving needs of the planetary science community.