4.4
GOES-R Data Dissemination
In the GOES R era raw sensor data rates will reach approximately 120 Mbps, compared to 2.6 Mbps from each of today's GOES. NOAA is investigating alternatives, including the use of X-Band spectrum, for the raw sensor downlink to Wallops Island to accommodate the downlink of these large data volumes to the ground. The GOES re-broadcast to its U.S. and foreign users will continue in the L-band RF spectrum; but will be more efficiently used and will have an expanded bandwidth. Even so, the GOES-R series satellite communications capability in the L-band seems to be restricted, from the available bandwidth and technology, to no more than 25 Mbps. Based upon the results being achieved in the NOAA-NESDIS data compression research program for the GOES-R series, the rebroadcast will likely be able to use compression (lossless and possibly near lossless). This use of compression enables a broadcast of more information in the same bandwidth. Utilizing data compression techniques, it is possible that GRB (GOES-R Rebroadcast) data may represent levels significantly higher than 25 Mbps. In this way NOAA will be able to significantly maximize the volume of GOES satellite science information it sends to other nations. The two types of data that are currently being considered for GOES R are the availability of a full set of this data (GFUL) and a rebroadcast of a subset of this data (GRB). GFUL contains the full ABI, HES, and other instruments Level 1b data sets, providing a data rate of more than 100 Mbps. This data could be sent via ground network or satellite rebroadcast. There are many design options possible that are still in the early phases.
With the rapid changes in communications, many options exist for the re-distribution of the calibrated/navigated data and products in the GOES-R era (commercial satellite, dedicated landlines, hybrid broadcasts consisting of both satellite and landlines). Fundamental to this is the continued use of satellite broadcasting. Many aspects of the distribution are being investigated and have not yet been determined, for example, how much and what is the nature of the data that needs to be rebroadcast via the GOES satellite. Alternate, complementary, data distribution methods such as the internet have a role. The appropriate data format(s) for GOES sensor science data in the GOES-R era are also being investigated. At this time, the infrastructure impact on user sites for the GOES-R series data to the acquired and processed has not been determined. Even the amount of radiance data versus products has not been determined regarding the GRB. The archive and access functionality is currently performed by the Comprehensive Large Array and Stewardship System (CLASS). This system exists and contains data from GOES and other observing systems, including POES and in the future NPOESS.