Operational Decoding of Data
A large amount of data are received at NCMRWF through GTS or by other means on a real-time basis and are decoded for further use. The WMO character codes, which are operationally decoded at NCMRWF, are (a) SYNOP/SHIP (surface observation from weather station over land or ships), (b) TEMP/TEMP-SHIP (upper-air radiosondes from land stations and ships) (c) PILOT (upper-air wind observations from land stations), (d) BUOY (automatic weather data from oceanic platforms), (e) AIREP/AMDAR (observations from aircrafts) , (f) SATOB (cloud motion vectors geostationary satellites) and (g) SATEM (temperature profile data from polar orbiting satellites).
These decoders were originally acquired from European Centre for Medium-Range Weather Forecasts (ECMWF), and were modified at NCMRWF to fix some of the errors experienced operationally and updated from time to time to accommodate the ongoing changes in the WMO coding procedure. The decoders have the inbuilt quality control checks which comprises of few checks as per quality control procedure3, set by WMO. The checks are (a) gross check for surface and upper level meteorological parameters, (b) internal consistency checks amongst the different meteorological parameters and (c) hydrostatic check for different levels of radiosonde temperature data.
At present the scatterometer wind data from European remote sensing satellite, ERS-2 and high-resolution visible winds from METEOSAT-5 are being received in BUFR code and decoded regularly at NCMRWF.
The decoding jobs are executed on Dec-Alpha (Digital) machine. These decoders run sequentially on GTS files, as soon as the data are received at NCMRWF. The digital machine takes on an average about five minutes to process each half-hourly GTS file. The raw data (GTS) and the decoded data are being archived permanently at NCMRWF.
Read more on Data Decoders at NCMRWF.