# Commission Implementing Decision (EU) 2018/620 of 20 April 2018 on the technical specifications for the Copernicus service component pursuant to Regulation (EU) No 377/2014 of the European Parliament and of the Council (Text with EEA relevance), Division 5.1: Satellites-Based Observation

Extent: E+W+S+N.I.

The core of the CAMS production shall consist of data assimilation and forecasting systems. The CAMS data assimilation system shall use the satellite observations to adjust the forecast model to stay as close as possible to the real atmospheric conditions. The models shall be initialised on a daily basis. To do so, forecasts from the day before shall be merged with observations to provide a best estimate of the atmospheric conditions at the start of the new forecast.
The CAMS global forecast services shall operate in real-time, delayed-mode and reanalysis configurations and shall use satellite observations data both for meteorological observations and atmospheric composition.
The categories of observations to be used shall include:
(a) the operational observations are the observations that are currently used in the CAMS data assimilation and forecasting systems;
(b) the pre-operational observations are the observations that are currently assessed to show readiness for operational use;
(c) planned observations are observations that are being considered to be implemented in the CAMS systems.
The CAM Service shall support ‘ad hoc’ near real time processing for some observations that are not routinely processed by the Copernicus space infrastructure or, more generally, by international space agencies concerning satellite data. The data coming from the atmospheric missions Sentinel 5p, 4 and 5 shall be taken into account in the development of the CAM service.

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Source: https://www.legislation.gov.uk/eudn/2018/620/annex/II/division/5/division/5.1 (the official version)
Page: https://openlegislation.uk/eu-decision-2018-620/annex-II/division-5/division-5.1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.