Chandra data archive operations

Abstract

The Chandra Data Archive plays a central role in the Chandra X-ray Center (CXC) that manages the operations of the Chandra X-ray Observatory. We shall give an overview of two salient aspects of the CDA's operations, as they are pertinent to the operation of any large observatory. First, in the database design it was decided to have a single observation catalog database that controls the entire life cycle of Chandra observations (as opposed to separate databases for uplink and downlink, as is common for many scientific space missions). We will discuss the pros and cons of this design choice and present some lessons learnt. Second, we shall review the complicated network that consists of Automated (pipeline) Processing, archive ingest, Verification & Validation, reprocessing, data distribution, and public release of observations. The CXC is required to deliver high-level products to its users. This is achieved through a sophisticated system of processing pipelines. However, occasional failures as well as the need to reprocess observations complicate this seemingly simple series of actions. In addition, we need to keep track of allotted and used observing time and of proprietary periods. Central to the solution is the Processing Status Database which is described in more detail in a related poster presentation.