Metop-B ASCAT 25 km Winds

Operational Near real time product

The ASCAT Wind Product contains measurements of the wind direction and wind speed above the sea surface. The measurements are obtained through the processing of scatterometer data originating from the ASCAT instrument on EUMETSAT's Metop-A satellite, as described in the ASCAT Wind Product User Manual.

Acronym : ASCAT25
Product navigator reference :


OSI SAF producer : Royal Netherlands Meteorological Institute
Identifier : OSI-102-b
Digital object identifier (DOI) 10.15770/EUM_SAF_OSI_NRT_2021
Acronym for EDC (APNM) : OAS025
Citation : See at bottom
Processing level : L2
Satellite input : Metop-B/ASCAT
Other input : ECMWF outputs (wind, SST, land-sea mask)
Temporal sampling : Continuous
Timeliness : ? The timeliness is the time elapsing from the sensing time of the last contributing file to the product dissemination to users. It is similar to the latency. 2 h 45
Spatial coverage : Global
Spatial sampling : 25 km
File Formats : WIND FTP Server (BUFR), WIND FTP Server (NetCDF3), EDC (BUFR), EDC (NetCDF3), EUMETCast (BUFR)
Characteristics & methods : Swath sigma0’s and wind vectors
Data Access
Credentials for access to OSI SAF tools For the FTP access, you need credentials which are provided on request, after registration on OSI SAF web site.

OSI SAF FTP (last 3 days)

Directory: ascat_b_osi

EUMETSAT Multicast

Redistribution by PO.DAAC

Accuracy Requirements
Target accuracy : Better than 2 m/s in wind component Stdev with an absolute mean difference of less than 0.5 m/s in wind speed on a monthly basis.
Verification/validation method : Triple collocation with NWP and buoys
Applications and users
Usage : * Operational Met Services (including assimilation in at least 8 NWP models, nowcasting)
* Operational analyses and ocean models
* Research or Environmental monitoring.
First date :
Full series temporal coverage : 2012-onwards
Detailed history :

The product series is operational since 2007:

  • Metop-A demonstration product from 28/03/2007, operational from 03/12/2008, discontinued on 15/11/2021
  • Metop-B product operational from 27/05/2013
  • Metop-C product operational from October 2019
Citation : OSI SAF Metop-B ASCAT 25 km Winds 2011-onwards, OSI-102-b, doi: 10.15770/EUM_SAF_OSI_NRT_2021. EUMETSAT Ocean and Sea Ice Satellite Application Facility. Data extracted from [distributor/distribution mean]: ([extracted period],) ([extracted domains],) accessed [download date]

The content within square brackets "[…]" is to be replaced with whatever distributor, period, domain or download date is relevant to the data being used. The "extracted period" and "extracted domains" are only needed if a subset of the data is being used.
Suggestions for "distributor/distribution mean": OSI SAF FTP server/the EUMETSAT Data Centre/EUMETCast/name and URL of a redistributor…
  • This ASCAT Multi-parameter product contains surface wind vectors over ocean and soil moisture index over land. Additionally, the backscatter values involved in the retrieval of the geophysical parameters above are also included, as well as several quality flags to facilitate the use of the data. This product superseded EO:EUM:DAT:METOP:ASCAT25 (Only Metop-A - Acronym for EDC (APNM) : OASW025) on the 28/02/2011 which contains only backscatter and wind information.

    See also OSI-102 (Metop-A ASCAT 25 km Winds)

    Product upgraded on 2018-09-25: geophysical model function CMOD7 used instead of CMOD5, auxiliary data " stress-equivalent ECMWF winds " instead of "real 10m ECMWF background model winds"

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