The EARS-ASCAT service collects ASCAT instrument data from Metop passes, via a network of HRPT stations, and retransmits Level 2 products via EUMETCast.

ASCAT swaths

The prime objective of the Advanced Scatterometer (ASCAT) instrument is to measure wind speed and direction over the oceans. Scatterometer data has also proved to be very useful in a variety of studies, including polar ice and tropical vegetation.

Water plays a unique role at microwave frequencies at which scatterometers are operated. It is the only naturally abundant medium with a high dielectric constant, so increasing the fraction of liquid water contained in soil, snow and vegetation increases the dielectric properties of these media, thereby significantly altering their scattering and absorption behaviour.

The backscattering coefficient, measured with scatterometers, is dependent on the dielectric properties of the soil surface layer, surface roughness, and vegetation. Thus, ASCAT provides useful data for ice and land applications, such as sea ice extent, permafrost boundary, desertification, etc. Because the scatterometer radar signal can penetrate the surface, ASCAT can also observe subsurface/subcanopy climate-related features.

More about the ASCAT instrument.

EARS-ASCAT Service Specification


Geographical coverage

ASCAT Geographical Coverage Map Core

Satellites supported

Metop-A, Metop-B and Metop-C, as shown on the tables on the Regional Data Service/EARS webpage.

Product Processing

  • Level 1 by EUMETSAT based on EPS Core Ground Segment processing s/w
  • Level 2 by KNMI using the operational OSI SAF processing s/w

Product Segmentation

Segments containing variable length of data.

Products via EUMETCast Europe

  • Level 2 Ocean Winds, as per the OSI SAF ASCAT service, BUFR format
  • Two products with 25 km and 12.5 km spaced grids respectively.

Timeliness via EUMETCast

30 minutes.

Products via RMDCN/GTS

As for EUMETCast

Archived in EUMETSAT


Further information

For more information on EARS-ASCAT see TD 14 - EUMETSAT Advanced Retransmission Service Technical Description (PDF,3 MB)

Full details on products can be found in the Product Navigator:
ASCAT Regional Coastal Winds at 12.5 km – Metop
ASCAT Regional Ocean Surface Winds at 25 km Node Grid – Metop

We use essential cookies to ensure that we give you the best experience on our website. To analyse website traffic we also use third-party performance cookies. If you are ok with the use of essential as well as non-essential cookies, please select Accept & Continue. Instructions on how to prevent the use of non-essential cookies are available under our Terms Of Use, or simply select Decline Cookies.