GOES direct broadcast service history and future

The National Oceanic and Atmospheric Administration´s (NCAA) Geostationary Operational Environmental Satellites (GOES) have provided direct broadcast of meteorological data to users since the mid-1970s. For the newest GOES series, GOES-R, GOES Rebroadcast (GRB) will replace the GOES Variable (GVAR) broadcast to continue to make ground-processed sensor data available to the weather operations, research, and Earth science communities on a free and open basis. The GOES-R Series will collect up to 50 times more data than current GOES satellites through instruments capable of advanced temporal, spatial, and spectral performance. Processed data will be broadcast to the user community with improved latency and enhanced resolution when compared to the current system. This paper describes the history of previous direct broadcast implementations for GOES satellites and the concept for the new GOES-R GRB data link. A dual polarization approach will be used to accommodate the 31 Mbps data rate within a frequency bandwidth constraint of 12 MHz using a standard downlink modulation at 1690 MHz (L-band). The GRB processed instrument data source will be packetized compliant with Consultative Committee for Space Data Systems (CCSDS) standard 133.0-B-l and will utilize lossless data compression to fit within allocated bandwidth. Data blocking and accompanying header metadata will be used to minimize risk of loss due to link errors and allow for user verification of data integrity. To aid user transition, an emulated GVAR (eGVAR) service will be provided via non-operational GOES-N/P series satellite transponders. Rebroadcast using dual circular polarization from geostationary orbit at L-band is a new implementation for NOAA satellite operations. This paper includes a discussion of the analysis and activities performed to date to reduce the implementation risk of the GOES-R GRB, and the impact of the significantly enhanced direct broadcast capability for current GOES users.