Migration Stories: Upgrading a PDS Archive to PDS4

Abstract:

Increasing bandwidth, storage capacity and computational capabilities have greatly increased our ability to access data and use them. A significant challenge, however, is to make data archived under older standards useful in the new data environments. NASA's Planetary Data System (PDS) recently released version 4 of its information model (PDS4). PDS4 is an improvement and has advantages over previous versions. PDS4 adopts the XML standard for metadata and expresses structural requirements with XML Schema and content constraints by using Schematron. This allows for thorough validation by using off the shelf tools. This is a substantial improvement over previous PDS versions. PDS4 was designed to improve discoverability of products (resources) in a PDS archive. These additions allow for more uniform metadata harvesting from the collection level to the product level. New tools and services are being deployed that depend on the data adhering to the PDS4 model. However, the PDS has been an operational archive since 1989 and has large holdings that are compliant with previous versions of the PDS information model. The challenge is the make the older data accessible and useable with the new PDS4 based tools. To provide uniform utility and access to the entire archive the older data must be migrated to the PDS4 model. At the Planetary Plasma Interactions (PPI) Node of the PDS we've been actively planning and preparing to migrate our legacy archive to the new PDS4 standards for several years. With the release of the PDS4 standards we have begun the migration of our archive. In this presentation we will discuss the preparation of the data for the migration and how we are approaching this task. The presentation will consist of a series of stories to describe our experiences and the best practices we have learned.