Regional ATOVS Retransmission Services (RARS) are operational arrangements for the real-time acquisition of polar-orbiting satellite data over a wide region containing a network of direct readout stations, and for their rapid delivery to the global user community through regional Processing Centres. ATOVS data can be obtained within 30 minutes of the satellite overpass, compared with a delay of between 1.5 and 7 hours for the global data transmitted by NOAA. The timeliness of the data is particularly useful for operational NWP centres.
These networks are co-ordinated by WMO through their RARS programme.
There are currently three RARS networks that distribute data from the ATOVS instruments on the NOAA polar-orbiting satellites:
- the EUMETSAT Advanced Retransmission Service (EARS) comprises a network of receiving stations in mainland Europe, North America, Canada, Greenland, the Arctic and the Canaries. The service was established in 2002.
- The Asia-Pacific RARS comprises stations in Australia, New Zealand, Antarctica, Japan, China, Singapore and Korea, and is co-ordinated by the Australian Bureau of Meteorology.
- The South American RARS currently comprises three stations in Brazil, co-ordinated by the National Institute for Space Research (INPE) and stations in Argentina and Antarctica, co-ordinated by the Comision Nacional de Actividades Espaciales (CONAE).
The Met Office also receives data locally from its direct readout station at Exeter.
The NWP SAF monitors the data in order to ensure a consistent data quality:
- Met Office EARS/RARS Monitoring Page: Comparison of locally-received, EARS-ATOVS, Asia-Pacific RARS and South American RARS data with global data.
- Météo-France EARS Monitoring Page: Comparisons between local AAPP processing and EARS-ATOVS level 1c files.
- ECMWF ATOVS radiance monitoring plots including EARS and Asia-Pacific RARS comparisons against NWP.