Man typing in laptop. Credit: kite_rin

EUMETCast Terrestrial reorganisation


Man typing in laptop. Credit: kite_rin
Man typing in laptop. Credit: kite_rin

EUMETCast Terrestrial will undergo reorganisation on 11 September 2023. This change is intended to optimise the bandwidth usage on the EUMETCast Terrestrial service.

Last Updated

31 August 2023

Published on

31 August 2023


The announcement channel for TER-3 (, source is now active. Users now launch the new TER-3 instance on their reception station, as specified in the announcement. This allows the users to test the connectivity to TER-3.

Test data is also planned to be disseminated on TER-3 starting 5 September.

The test (dummy) files will be disseminated on each of the new channels every 10 minutes, with the following file names:
<new channel="" name="">_YYYYMMDDTHHMM00_DUMMY.FILE.CHA (~1 Kbytes each file)
Example: T03-S3A-01_20230905T120000_DUMMY.FILE.CHA

This will demonstrate that the channels are working, and give users the time to implement the changes needed to receive the new channels and test them.

The test files will be delivered to the target directory of the new channels. If the dummy files mentioned below could be an issue for any processing tools running on the reception station the user can change the target directory for the new channel under cast-client-channels_ter-3.ini (or the equivalent file) to a different location.

Test dissemination will stop in the morning of 11 September, before migration takes place.

There are currently two instances where the TER-2 is used for disseminating the Sentinel-6A data and TER-1 is used for disseminating all other data.

A new EUMETCast Terrestrial instance (TER-3) will be created to disseminate data that is exclusively available on EUMETCast Terrestrial and not on EUMETCast Satellite.

TER-1 instance will continue to be used for data that is also available on the EUMETCast Satellite service (Basic, HVS-1, HVS-2, and AFR-1) and TER-2 will continue to be used to distribute Sentinel-6A products without any changes.

The datasets that are moved from TER-1 to TER-3 will have the same channel structure. However, the channel name prefix will change from 'T01-' to 'T03-' (eg T01-S3A-01 becomes T03-S3A-01), and the multicast address will change from '232.223.222.X' to '232.223.224.Y' (eg becomes The same UDP (User Datagram Protocol) port is used.

The source address for the new service, TER-3, is Users must allow traffic from this IP, the same rule as the one for (TER-1) should be applied, if there are such rules.

The table below provides more details on the breakdown of the data distribution among all Terrestrial instances after the reorganisation.

Terrestrial service Total bandwidth (Mbps) Data
TER-1 240 EPS, MSG, Sentinel-3A/B, Sentinel-5P, Third Party data, MTG
TER-2 168 Sentinel-6A
TER-3 230 Sentinel-5P L1B, Sentinel-3A/B OLCI L1 FR, Sentinel-3A/B SLSTR L1B, FY3 HIRAS, FY4 GIIRS, GOSAT, MTG HRFI-FD (4 high-res full-disk bands)

To avoid disruption of current reception, the sample configuration files from the EUMETSAT sftp server can be downloaded and edited to match the local reception station parameters (eg local interface IP address, user_name, user_key, local paths, etc.) and can be placed under the same folders along with the TER-1 configuration files.

Once these changes are completed then the new TER-3 instance can be started in the same way with TER-1 or TER-2.

The migration will take place on 11 September, so the users who receive data on the reorganised channels must perform the changes described above, preferably a couple of days before the reorganisation, and ensure that the TER-3 instance is running on the station. This will enable it to automatically start receiving data once the migration is activated on the server-side.

For GRE users, the update of the tunnels will be coordinated with GEANT and the users will not need to update their tunnel configurations on the station.

Full information and details of each Terrestrial instance (TER-1, TER-2 and TER-3), before and after the reorganisation, can be found on the EUMETCast Knowledge Base.

For more information, contact our User Service Helpdesk.