Home Ground Systems GAS 

Project: GOES-R GAS & ADRS
Project Status:
NOAA Mission Goal: Weather & Water, Commerce & Transportation, Climate
Project Manager: Rick Vizbulis, OSD Ground Systems Division

Project Stage:

Project Description: To support legacy GOES missions, the Environmental Satellite Processing Center (ESPC) in OSDPD provides ingest of telemetry data and subsequent satellite product generation and distribution services. The Environmental Satellite Processing and Distribution System (ESPDS) will be ESPC’s next generation system for the delivery of these services using an enterprise approach across the various architectural segments. The enterprise data storage and dissemination component of the ESPDS is called Product Distribution and Access (PDA), and the GOES-R Access Subsystem (GAS), a functional subsystem of the GOES-R Ground Segment (GS) for distributing GOES-R products and data, will be built as part of the ESPDS PDA.

GOES-R data ingest, processing, and partial distribution capabilities (focusing primarily on real-time delivery of GOES-R data and imagery to the National Weather Service) are being developed as part of the Core GS, while the remaining data distribution to the general user community, temporary storage, and user access capabilities are being developed as part of the ESPC’s next-generation ESPDS mission. A notional diagram of the GOES-R data distribution partitioning is shown below.

The Product Distribution (PD) element of the Core GS interfaces to the Comprehensive Large Array-data Stewardship System (CLASS) to support the archive of GOES-R data and information and distribution to non real-time users, and interfaces to AWIPS for distribution of critical cloud and moisture sectorized imagery products. The PD will also interface with the GOES-R Algorithm Working Groups (AWGs) to exchange data products, calibration and other auxiliary information necessary for accurate product generation. GAS will be used to distribute the full set of GOES-R end-products (L1b, L2+) to general authorized users. GAS, however, will not provide any value-added data transformation services such as spatial subsetting/subsampling, re-projection/ remapping, or reformatting of the incoming core GS data products. 

The figure below shows a high level diagram for the GAS data flows between Data Reception, Storage, Access, and Distribution. Vertical red lines indicate interfaces between GAS and external elements in the data flow. As such, it can be seen that GAS itself serves as the interface between the GOES-R Core system and the general user community.

Data Reception receives GOES-R satellite data products via push transfer from the GOES-R GS PD Core data servers. These data products include L1b and L2+ GOES-R Products, Ancillary Data, Metadata, Mission Operations Data and Instrument Calibration Data.  Handshaking protocols are used between the GOES-R PD and GAS to ensure proper transfer of data and to enable retransmission requests by GAS should an error occur. Upon successful data reception, GAS routes the received data from Data Reception to Data Storage, consisting of a cataloged 7-day revolving temporary storage to allow fast data search and discovery by authorized users via Data Access.

Data Access allows authorized users to discover, search and request GOES-R data products through a user interface (UI), which provides internet access to a configurable set of products and services.  The Data Access includes the capabilities for users to create and modify their account; create and submit searches; create, modify, and submit subscriptions and ad hoc requests; receive the status of the GOES-R system and their data product requests; and receive assistance from and access to help services. Registered users may search for data currently available in Data Storage and data anticipated in the future via the UI.  Data may be searched based upon configurable search parameters, such as geographic area, temporal period, channel number, product type or instrument, among others. Registered users may request, either via subscription or ad hoc requests, data identified in the data search results or they may directly specify data and product parameters. Data Access provides Data Request status to users, notifying users when a data request cannot be filled.  Users may also query data request status information via the UI.

The Data Distribution function distributes requested data products to users by either a data push (GAS initiated) or data pull (user initiated). Data products are considered “available” once the last data bit of the product is transferred from the GOES-R GS to the Data Reception function of the GAS. The Data Distribution function will also monitor and verify the success of the push and pull transfers and enforce a time-out policy. In the event of a data push transfer failure, Data Distribution will attempt to initiate the transfer a configurable number of times before declaring the transfer unsuccessful.

Images:

Artist rendition of GOES-R Spacecraft Simulated GOES-R channel images High level system diagram

Additional Information:

ftp://ftp.osd.noaa.gov/public/OSD/GSD/GAS/GAS_Conops.pdf

ftp://ftp.osd.noaa.gov/public/OSD/GSD/GAS/System_Operations_Concepts.pdf