CGMS 44: EUM-WP-16.ppt (May 2016) Coordination Group for Meteorological Satellites - CGMS Action closure: MTG FCI and IRS Format Presented to CGMS-44 Working Group IV session, agenda item IV/7 Slide: 1

CGMS 44: EUM-WP-16.ppt (May 2016) Coordination Group for Meteorological Satellites - CGMS Slide: 2 Action was: Provide overview of current proposed disseminated standard for high- resolution imaging and hyper-spectral instruments for GEO. Contents: 1.Introduction 2.SEVIRI to FCI Data Collection Differences 3.IRS data collection 4.Evolution of the volume of data 5.MTG Data in netCDF format 6.Chunking and compression

CGMS 44: EUM-WP-16.ppt (May 2016) Coordination Group for Meteorological Satellites - CGMS 1. Introduction The Flexible Combined Imager (FCI) will be launched on the four MTG Imager (MTG-I) satellites and will continue the Full Earth Scanning service (FES) and Rapid Scanning Service (RSS) currently provided by the MSG SEVIRI instruments. The IRS instrument will be launched on the two MTG Sounder (MTG-S) satellites. This is a new service. The data will be disseminated progressively starting in The level 1 datasets offer the users information necessary to interpret and use the data they contain. New information related to the instrument design and data quality are introduced. Extended metadata is planned to facilitate user data searches. Slide: 3

CGMS 44: EUM-WP-16.ppt (May 2016) Coordination Group for Meteorological Satellites - CGMS 2. SEVIRI to FCI Data Collection Differences SEVIRI Continuous E to W scan S to N motion between swaths Swath width 9km FCI Alternate E to W then W to E scans S to N motion between swaths Swath width 180km (excluding overlap) Reversal of detector order for yaw flip, but not scan pattern. Slide: 4

CGMS 44: EUM-WP-16.ppt (May 2016) Coordination Group for Meteorological Satellites - CGMS 3. IRS data collection L1 products are generated for all Zones/LAC L2 products are only generated for Zone/LAC 4 Earth disc is split in 4 zones. Europe (Zone 4) is scanned during 15mn every 30mn. The rest of earth is scanned less frequently (see next slide). Overall repeat cycle is 6 hours. Slide: 5

CGMS 44: EUM-WP-16.ppt (May 2016) Coordination Group for Meteorological Satellites - CGMS 3. IRS data collection Slide: 6

CGMS 44: EUM-WP-16.ppt (May 2016) Coordination Group for Meteorological Satellites - CGMS 4. Evolution of the volume of data On MSG, all the data are available via EUMETCast by satellite to all potential users. On MTG, the volume of generated data being higher, there is a need to select, on a per product basis, the appropriate distribution mechanism: o EUMETCast by satellite (Europe, Africa), o EUMETCast terrestrial, o On-line data access via Internet, o Archive retrieval, o GTS for the global community. Slide: 7 The selection of the distribution mechanism will be based on: o User needs, o Volume of data / products, o Number of users interested in a given product, o Location of users (network accessibility), o Level of service (full operational service vs best effort).

CGMS 44: EUM-WP-16.ppt (May 2016) Coordination Group for Meteorological Satellites - CGMS 5. MTG Data in netCDF format SEVIRI data is provided in HRIT for level 1.5, as defined by CGMS (a compact binary representation). SEVIRI L2 data are provided in a number of formats including BUFR, GRIB and netCDF (according to the need of the user community). For the MTG FCI and IRS at level 1, netCDF-4 (enhanced data model) was chosen as it has the following features: Datasets are self describing Able to handle large data sizes Subsetting capability by grouping It is a commonly used format Formats other than netCDF-4 may be used (e.g. BUFR for global NWP/GTS) if required and technically feasible either directly or via a converter (e.g. netCDF to BUFR).  Under investigation. Slide: 8

CGMS 44: EUM-WP-16.ppt (May 2016) Coordination Group for Meteorological Satellites - CGMS 6. Chunking and compression a)For timeliness and bandwidth optimization, the L1 data is processed and transferred as “chunks” of the full repeat cycle. b)Thus chunks are presented to the dissemination and archive. This presents the potential for the user to access chunks from a repeat cycle which provides fast/basic geographic subsetting. c)A special compression (lossless CharLS based on JPEG-LS) will be applied to the disseminated data to reduce the dataset size. d)This will require a decompressor on the end-user side, but once installed it should function invisibly to the user (like the netCDF inbuilt zip compression). e)IRS L1 data are compressed using principal Components (PC). f)Discussions will continue in 2016 with Industry to establish a consolidated level 1 format. Slide: 9