Figure 1: Coverage of the Meteosat-9 and Meteosat-7 satellites.

DCS System Overview

Data Collection Systems are provided by several geostationary meteorological satellite operators, giving almost total coverage around the world, except the polar regions. The DCS is particularly useful for the collection of data from remote and inhospitable locations where it may provide the only possibility for data relay.

The Meteosat satellites located at 0° longitude, and over the Indian Ocean, acquire DCP data, in the form of observations and environmental parameters, from operators of DCP, which are located within the footprint of the satellites. The satellites have onboard communication channels for regional and international DCP access. DCPs are automatic, or semi-automatic, in-situ environmental observing systems, which may be integrated into an automatic weather station at a remote site; an automatic river or tide gauge, or on an aircraft, ship, balloon or buoy. If the platform is always under the footprint of a single geostationary meteorological satellite it is allocated to a regional transmission channel. If it is located on a ship or aircraft, which travels across the footprint of several satellites, it is allocated to an International channel.

Figure 2: Data flows for data from Meteosat-9 and Meteosat-7 satellites.

TD16 — Meteosat Data Collection and Distribution (PDF, 1 MB) gives detailed information about the services for DC operators and DCP manufacturers.

DCS types

DCPs can be one of the following:

• Self-Timed — transmits at regular intervals and controlled by GPS, according to a schedule jointly agreed by the user and the satellite operator.
• Alert — transmits short messages, not exceeding 10 seconds, when the value of one or more measured parameters exceeds a pre-set threshold.
• Hybrid — combines self-timed and alert modes.

The system supports both standard (100bps) and high-rate (1200bps) DCPs, allowing for improved capabilities and warnings of potentially devastating natural phenomena such as tsunamis.

DCP channels

DCS processing and distribution

Data is processed and distributed to the user via these mechanisms (Figure 2 shows the DCP data flows):

EUMETCast — Comms Satellite Multicast, which covers Europe, Africa and South America.

LRIT Direct Dissemination — via the prime Meteosat Satellite (MSG-2 LRIT).

Global Telecommunications System (GTS) of WMO, used to transmit environmental data to meteorological services throughout the world.

Internet — manual download from the website via secure log in. Please direct all log in requests (including your DCPs) to our User Service Helpdesk.

DCP operators

To become a DCP operator you need to complete a EUMETSAT DCP Admission Form (PDF, 99 KB) giving the full details of the operator, including the equipment to be used; time slots required; type of data to be transmitted, and the preferred method of data distribution.

How to retrieve data via the internet

Following changes to the MSG DCPs, downloaded from the Public DCP Service, they will now include a DCP quality record.

The downloaded gzip DCP files will have the following format:

• The first 86 Bytes will contain the DCP Service header, as explained on this table (PDF, 64 KB).
• The following 31 Bytes will contain the DCP Quality record (DCP_QUALITY), as described in appendix A.7 of MSG Ground Segment LRIT/HRIT Mission Specific Implementation (PDF, 825 KB).
• The DCP message (DCP_MESSAGE) will appear after the DCP Quality record. This is also described at appendix A.7 of the above document. The size of the DCP_Message is variable.

The above sequence is repeated in subsequent messages throughout the gzip file.

Purchasing a Certified DCP Radio Transmitter

All DCP operators wishing to use the Meteosat system to relay DCP bulletins and messages are required to operate with a certified DCP Radio Transmitter. It is the responsibility of the operator to ensure that the DCP equipment they purchase for use with the Meteosat system has been correctly certified.

For further information on certified DCP transmitting equipment, contact a DCP manufacturer.