Measuring wind speed and direction over the oceans
EARS-ASCAT collects ASCAT instrument data from Metop passes, via a network of HRPT stations, and re-transmits Level 2 products via EUMETCast.
31 May 2022
28 April 2020
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.
EARS-ASCAT service specification
Metop-B and Metop-C, as shown on the tables on the Regional Data Service/EARS webpage.
- 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
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
Products via RMDCN/GTS
As for EUMETCast
Archived in EUMETSAT
For more information on EARS-ASCAT see TD 14 - EUMETSAT Advanced Retransmission Service Technical Description
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
Other EARS services
EARS-ATMS collects data from the ATMS instrument on board the JPSS spacecrafts, operated by NASA and NOAA.
EARS-ATOVS provides the European meteorological community with sounder data covering data-sparse areas, within 30 minutes of the instrument observations.
The EARS-CrIS service collects data from the CrIS instrument onboard the JPSS spacecrafts, operated by NASA and NOAA.
EARS-IASI collects IASI instrument data from Metop satellite-passes via a network of HRPT stations and re-transmits Level 1c and pilot Level 2 products.
EARS-MERSI complements the Metop and the US POES and SNPP/JPSS satellites currently covered by EARS.
EARS-VASS (Vertical Atmospheric Sounding Service), complements the Metop and the US POES and SNPP/JPSS satellites currently covered by EARS.