Observation data are acquired and processed within the EPS-SG system. In order to distribute this data to end-users, a number of operational data delivery services have been defined.
Global Data Service
The instrument data will be provided to the users in near real-time, after their acquisition and processing by the ground segment to obtain geometrically consistent and calibrated radiance values, and a number of geophysical variables with global coverage. Processed data will be transmitted to users primarily via EUMETCast. Meteorological data and products will also be sent and relayed via the WMO Global Telecommunications System (GTS) and the Regional Meteorological Data Communication Network (RMDCN) to the National Meteorological Services and ECMWF.
The time between observation by the instrument and delivery of the data to the users, via EUMETCast, will nominally be 70 minutes or better, depending on geographical location of the observations.
As a typical example of an instrument coverage pattern, Figure 2 below shows the global spatial coverage for the IAS mission after 24 hours, driven by the ground track of the satellite (shown as blue lines).
Figure 2: IAS Coverage with Metop-SG ground track
Regional Data Service
The regional data delivery service differs from global data service because it is nly applicable to a specific Area of Interest (AOI) and the timeliness for regional data is improved to 30 minutes versus 70 minutes for the global data.
The regional data service uses a network of direct broadcast data receiving ground stations and, possibly, a prioritisation of data from the Northern polar station to rapidly transmit data from a defined geographical Area of Interest (AOI) to users. The baseline regional AOI currently covers the North Atlantic and European regions between 30° to 80° North and 65° West to 50° East, as shown as the black box in Figure 3.
The plan is to re-use selected existing EPS EARS direct broadcast station sites to cover the AOI and add complementary stations as necessary.
Data received at the stations is transmitted in real-time to EUMETSAT Headquarters for processing and transmission to end users via EUMETCast. AOI data will be delivered to users within 30 minutes of sensing, making it suitable for short range regional numerical weather prediction models.
Not every satellite orbit will be visible from the AOI. Over five days there willbe 24 descending and 28 ascending passes over the AOI, i.e. about three-quarters of the orbits will have some degree of visibility over the AOI, either on their ascending or descending parts.
Local data service
All instrument data will be broadcast in real-time by the satellites to receiving stations in visibility of the satellite (direct broadcast). This transmission will be in X-Band and allow reception via a 3-meter antenna and user station. Data is only available for the field of view of the satellite, but it is available in real-time, making it useful for nowcasting applications and short-range numerical weather prediction.
Instrument calibration data, satellite telemetry data and administration messages will also be transmitted to users as part of the direct broadcast data.
Archive and Retrieval
The instrument data will be archived and be available for retrieval via the internet.