The Chandra Observational Ontology: Tying the Threads Together

The Chandra Data Archive (CDA) has been providing links between data and astronomical publications to the Astrophysics Data System (ADS) for many years as part of our maintaining of the Chandra Bibliography. In the past year the CDA and ADS have embarked on an observation ontology project which has expanded our exchange of information to include details about the observations, proposals, and bibliographic classifications related to the data in publications. ADS is incorporating this additional information into a new semantic literature search tool which is currently under development. In this paper we discuss what an observatory needs to collect to provide useful metadata to this new ADS service. This process has brought to light several important pieces of information about observations which were not being collected in a systematic way. We will also discuss how the CDA plans to incorporate the collection of this information into its existing infrastructure.