NOAA GOES-R Series Extreme Ultraviolet and X-Ray Irradiance Sensors (EXIS) Level 0 Data

This data collection consists of archived GOES-R Series Extreme Ultraviolet and X-Ray Irradiance Sensors (EXIS) Level 0 data from the operational GOES-East and GOES-West satellites. The Geostationary Operational Environmental Satellite-R (GOES-R) series provides continuity of the GOES mission through 2035 and improvements in geostationary satellite observational data. GOES-16, the first GOES-R satellite, began operating as GOES-East on December 18, 2017, and GOES-18 began operating on March 1, 2022 replacing GOES-17 as GOES West in early January 2023. GOES-19 began operational service in April 7, 2024, replacing GOES-16. On board EXIS are two main sensors, the Extreme Ultraviolet Sensor (EUVS) and the X-Ray Sensor (XRS) which monitor solar irradiance and detect solar flares that impact the upper atmosphere. The EXIS Level 0 data are composed of Consultative Committee for Space Data Systems (CCSDS) packets containing the science, housekeeping, engineering, and diagnostic telemetry data downlinked from the instrument. The Level 0 data files also contain orbit and attitude/angular rate packets generated by the GOES spacecraft. Each CCSDS packet contains a unique Application Process Identifier (APID) in the primary header that identifies the specific type of packet, and is used to support interpretation of its contents. Users may refer to the GOES-R Series Product Definition and Users’ Guide (PUG) Volumes 1 (Main) and 2 (Level 0 Products) for Level 0 data documentation. Related instrument calibration data and Level 1b processing information are archived and available for order at the NOAA CLASS website. The EXIS Level 0 data files are delivered in a netCDF-4 file format, however, the constituent CCSDS packets are stored in a byte array making the data opaque for standard netCDF reader applications. The EXIS Level 0 data files are packaged in daily tar files (data bundles) by satellite for the archive. Recently ingested archive tar files are available for 14 days on a CLASS-hosted anonymous FTP server for users to download. Data archived on tape are available to users by special order through NCEI customer service.