The CloudSat Data Processing Center "Day-in-the-Life" diagram provides a graphical display of how data flow through the data processing system.
As it arrives, Raw CloudSat data will be pre-processed to form a time-ordered data file (with duplicate data packets removed and missing data blank-filled/flagged) that is stored on the local DPC mass storage system by orbit. Once a day of CloudSat Science Data and the corresponding Definitive Ephemeris are available, the level 0 to level 1b processor will be run.
After the level 1b data and all necessary ancillary data are available, the level 2 data processes will be run. Some of the level 2 products require input from other level 2 processes, and also require unique ancillary (non-CloudSat) data as input. To compensate for potential delays in the delivery of ancillary data, equipment failures, or other delays, CIRA will provide mass storage capacity to "stage" data for up to 45 days. Once the level 2 input data are received each data day will be processed in less than a day of "processing time" to maintain the CloudSat data processing schedule.
Most of the CloudSat data and products will be made available to the CloudSat Science Teams, and other authorized users, via a web-based data server during the on-orbit phase, and all CloudSat products will be sent to the Langley DAAC after the end of the operational phase.
Output Standard Data Products will be quality controlled, stored on tape (or CD/DVD), and sent to the supporting NASA DAAC at the end of the mission for permanent archive. CloudSat data will be stored on both CD (source code and documentation) and DLT tapes (larger Standard Data Products files). These media will be stored in a dedicated data storage room with climate controls and controlled access. The DLT media we have chosen has an expected lifetime (30 years) that far exceeds the mission lifetime. CIRA will also produce a tape copy for off-site storage.
The Data Processing Center External Interfaces Diagram gives a summary of the DPC external interfaces and the data/information that is passed to and from each element. The following sections will discuss each of these elements and their interaction with the DPC.