Mode-S EHS messages are procured by the Met Office from Flightradar24, a global flight tracking service. These messages are routed directly from Flightradar24 to EMADDC where they are processed into derived meteorological observations.
As with the ‘EMADDC European Mode-S EHS data’ the process consists of quality control of Mode-S EHS data, conversion of magnetic to true heading, and aircraft specific corrections for heading and temperature.
Mode-S EHS data is only available where aircraft are interrogated for this information. The map below shows the typical coverage of the ‘EMADDC Met Office Global Mode-S EHS data’. Live coverage is shown on the Data QC web page.
Note that Europe is well covered by the ‘EMADDC European Mode-S EHS data’ so the Met Office do not fund Mode-S EHS messages from FlightRadar24 for the majority of Europe.
Semi-operational ‘EMADDC Met Office Global Mode-S EHS data’ is available since September 2024 for use by National MET Services in order to perform official duties. No distribution is permitted beyond this group. Derived Products or Non-retrievable Value-Added Services derived from source data, for example NWP, within which original raw data can no longer be identified and therefore cannot be extracted, will have no restriction on their use or distribution.
The Licensee shall make acknowledgement to the “Met Office and KNMI EMADDC” in any reproduction of data, publication of papers, reports, literature to Licensees, or presentations arising out of the use of the Data using the following acknowledgement:
“Data supplied by the Met Office and KNMI EMADDC”
In order to access the data, users must sign a data licence with the Met Office. Please contact Globalmode-s@metoffice.gov.uk to apply for a data licence. A sample data licence can be found here: EMADDC MET Office Global Data License
The data is made available through the KNMI DataPlatform (KDP). After obtaining a data license, requests for access to the ‘EMADDC Met Office Global Mode-S EHS data’ can be directed to opendata@knmi.nl. The observations are provided in three distinct datasets, each featuring a different file format.
New is the creation of files in NetCDF Format. For more details see the Data Format page.
EMADDC offers an open-source Python script designed to utilize the KDP Notification Service for the automatic downloading of data when it becomes available. The script, along with its documentation, can be accessed at the following link: https://gitlab.com/KNMI-OSS/emaddc/kdp-notification-client.
Additional documentation related to KDP and the KDP APIs is available at https://developer.dataplatform.knmi.nl
Addtional information on the dataset
As of October 2024, the data is classified as semi-operational. Prior to this period, the data processing was in a testing phase, during which several modifications and corrections were implemented. Consequently:
- data generated before July 11, 2024, employs different units in the created netCDF files for flightlevel (fl) and wind speed (wspd).
- an issue concerning incorrectly decoded positions for certain observations was resolved on September 27, 2024.
- a quality control issue led to a reduced number of observations being produced between August 19, 2024, and September 7, 2024.
To note: in the NetCDF dataset Flight Level and Wind Speed are provided in different units compared to the other datasets.
Historical background and description of the EMADDC Met Office Global initiative
KNMI and Met Office collaborated in the SESAR Deployment Program Pilot Common Project (PCP) EMADDC (2016-2024). Met Office set up a system of local ADSB/Modes-S EHS receivers in Great Britain and provides the data operationally to EMADDC. The processed data of Great Britain is included in the EMADDC data set.
In 2022 a follow-up activity was discussed resulting in signing a Partnership Agreement between KNMI and Met Office for the processing of global Mode-S EHS in 2023. Met Office signed a contract with Flightradar24 (FR24) in 2023 and the global Mode-S EHS data is being made available to EMADDC. In September 2024 the data set was made available semi-operational for test purposes. The planning is to have the system fully operational in May 2025.
The EMADDC system ingests and processes the global data and makes the data available via the KNMI Data Portal. The data set is available to National Meteorological Hydrological Institutes and ECMWF after signing a data license with the Met Office.
The provision of the global Mode-S EHS data set via FR24 and the processing by EMADDC is funded by the Met Office. KNMI provides and maintains the EMADDC system and makes the data set available free of charge to authorised stakeholders.
Description of global areas
The quality of the derived observations is determined by comparing to the ECMWF NWP. For technical reasons the following sections of the ECMWF NWP are being used, where MSA depicts EMADDC and the other regions EMADDC Met Office Global.
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