As of 16 April 2026, EMADDC enables authorized and registered users to access and test observations processed through the new, real-time EMADDC 3.0 system.
The EMADDC 3.0 format introduces incremental updates compared to R2.2. The CSV format has been slightly revised, while NetCDF and BUFR formats currently remain aligned with R2.2. The NetCDF format is expected to evolve in a future update to become fully CF-compliant and aligned with WIS 2.0 standards.
All EMADDC 3.0 data are exclusively available via KNMI’s Data Platform (KDP) at
https://dataplatform.knmi.nl. In contrast to R2.2, datasets in EMADDC 3.0 are no longer separated by file format. Instead, CSV, NetCDF, and BUFR formats are all available within the same dataset, allowing users to select their preferred format without switching datasets.
Another important change is the introduction of globally defined datasets. Access to specific data sources is now determined solely by the licenses a user has signed. For example:
- Users with the EMADDC Met Office Global license will have access to data from sources such as FlightRadar24 (FR24).
- Users with only a KNMI license may instead access global data from sources such as ADS-B Support (adsb-sup).
- Users holding multiple licenses will have access to multiple corresponding data sources.
Within each dataset, duplicate observations have been removed. Users are therefore strongly advised not to combine data from multiple datasets, as this may reintroduce duplicates.
EMADDC 3.0 improves data timeliness and delivery:
- Files are generated at fixed 5-minute intervals.
- Data are typically available within a maximum latency of approximately 6.5 minutes w.r.t. the first obseration (including processing and publication time).
- Delayed observations may result in updated files for the same time window. These are distinguished using an incrementing sequence number, similar to R2.2., and now appended to the filename.
A key difference is that the sequence number is now included in the filename (as a post-fix). Files are no longer overwritten, and users should select the appropriate version for their use case, avoiding the use of multiple files for the same interval to prevent duplication.
Additional changes include:
- The removal of the “fast” and “regular” file distinction.
- Availability of all observations exclusively via KDP.
- Planned updates to the KDP download script to support filtering by file format/extension.
- The discontinuation of FTP access once R2.2 is fully deprecated.
Please note that all timestamps in EMADDC data are provided in UTC.
The CSV file format is comma seperated and has extension csv and when distributed are compressed using gzip. Files contain the following parameters obs_id, date, time, Mid, latitude, longitude, flight_level, wind_speed, wind_direction, temperature, flight_phase, roll_angle, source, radar_sic, whitelist_flag and qc_flag. A description of these parameters is found in the table below. Currently, EMADDC only provides output observations that have passed quality control and hence the qc_flag will always be 0 but this might change in the future.
To distinguish between derived Mode-S EHS observations and MRAR observations, two files are provided:
- EMADDC_<DATASET_NAME>_<YMD>_<HM>_<YMD>_<YM>.csv.gz
- EMADDC_<DATASET_NAME>_MRAR_<YMD>_<HM>_<YMD>_<YM>.csv.gz
In case no MRAR file is present for a certain timestamp, this is likely the result of lack of data and not a processing error, unless the corresponding regular file is also missing.
Important notice: the MRAR data output is not quality controlled and provides the wind and temperature as provided by the aircraft and as received by receivers.
The first time indicates the time of the first observation in the file and the second time indicates the time of last observation. Observations are sorted dy date and time (dtg).
In certain cases, for example due to quality control, certain parameters are invalid and hence are missing.
Also new in the CSV files is a line header (lines starting with a #) to indicate the software version used to produce the file and a row indicating the parameter in each column. The latter should help processing the proper columns and to avoid mismatches:
- Software Version: TBD
- Process Time: Time at which the file was processed on EMADDC system (in UTC)
- Sequence Number: File sequence, 0 for first processed file and value is incremented upon subsequent runs (e.g., due to delayed input files)
- Offset: Offset value for each obs id. Actual DB obs_id is equal to offset + obs_id per observation.
Following the header is the column definition names: obs_id,date,time,Mid,latitude,longitude,flight_level,wind_speed,wind_direction,temperature,flight_phase,roll_angle,source,radar_sic,whitelist_flag,qc_flag
|
Description
|
Parameter
|
Units
|
Source
|
Remark
|
| Observation ID |
obs_id |
|
EMADDC |
Add offset to get DB value, values are rotated hourly
|
| Date |
date |
|
YYYYMMDD |
Radar / GPS Receiver |
| Time |
time |
|
HHMMSS.FFF |
Radar / GPS Receiver |
|
Anonymous Aircraft Mode-S ID ('M'+24-bit)
|
Mid
|
Mxxxxxx
|
BDS 2.X / Radar
|
|
|
Latitude
|
latitude
|
deg (DDD.dddd)
|
Radar / ADS-B
|
|
|
Longitude
|
longitude
|
deg (DDD.dddd)
|
Radar / ADS-B
|
|
|
Flight Level
|
flight_level
|
FL
|
Mode-C/S
|
|
|
Wind Speed
|
wind speed
|
m/s
|
EHS: Derived MRAR: BDS 4.4
|
|
|
Wind Direction
|
wind direction
|
deg
|
EHS: Derived MRAR: BDS 4.4 |
|
|
Temperature
|
temperature
|
Kelvin
|
EHS: Derived MRAR: BDS 4.4 |
|
|
Phase
|
flight_phase
|
3, 5, 6, 15
|
Calculated
|
See BUFR detailed phase of flight definition below
|
|
Roll Angle
|
roll_angle
|
deg (- left turn)
|
BDS 5.0
|
|
|
Source
|
source
|
-
|
Filename
|
|
|
SIC (Station Identification Code)
|
radar_sic
|
-
|
station ID
|
|
|
Whitelisted
|
whitelist_flag
|
-
|
Calculated
|
0 = wind and temp whitelisted
1 = wind not whitelisted temp whitelisted
2 = wind whitelisted temp not whitelisted
3 = wind not whitelisted temp not whitelisted
4 = whitelisting not performed
|
|
QC Flag
|
qc_flag
|
-
|
Calculated
|
For now qc_flag = 0
|
The EMADDC NetCDF format is based on the NetCDF4 standard, using the .nc4 file extension. When distributed, files are typically compressed using gzip to reduce data volume.
Each file contains the following parameters: obs_id, dtg, Mid, lat, long, fl, wspd, wdir, temp, phase, roll angle, source, SIC, wl_flag, and qc_flag. A detailed description of these parameters is provided in the table below. EMADDC wishes to update the format in the near future to become CF and WIS 2.0 compliant.
At present, EMADDC distributes only observations that have passed quality control, meaning the qc_flag is currently always set to 0. This may change in future as additional data streams and quality levels are introduced.
To distinguish between derived Mode-S EHS observations and MRAR observations, two file types are provided:
It is important to note that MRAR data are not quality controlled. These files provide wind and temperature observations exactly as reported by the aircraft and received by ground stations.
File naming follows a consistent convention:
-
The first timestamp represents the time of the first observation in the file.
-
The second timestamp represents the time of the last observation.
-
Observations within each file are sorted by date and time (DTG).
In some cases, certain parameters may be unavailable for specific observations (for example due to quality control filtering). These values are represented as missing values (NaN) within the dataset.
Each NetCDF file also includes metadata stored as global attributes, providing additional context and information about the dataset, as described below.
- Software Version: TBD
- Creation Date: Date and time at which the file was processed on EMADDC system (in UTC)
- Sequence Number: File sequence, 0 for first processed file and value is incremented upon subsequent runs (e.g., due to delayed input files)
- Title and Author information
|
Description
|
Parameter
|
Units
|
Source
|
Remark
|
| Observation ID |
obs_id |
|
EMADDC |
|
| Date and Time |
dtg |
|
YYYYMMDD
|
Radar / GPS Receiver |
|
Anonymous Aircraft Mode-S ID ('M'+24-bit)
|
Mid
|
Mxxxxxx
|
BDS 2.X / Radar
|
|
|
Latitude
|
lat
|
deg (DDD.dddd)
|
Radar / ADS-B
|
|
|
Longitude
|
lon
|
deg (DDD.dddd)
|
Radar / ADS-B
|
|
|
Flight Level
|
fl
|
m
|
Mode-C/S
|
Caution; FL is provided in meters |
|
Wind Speed
|
wspd
|
m/s
|
EHS: Derived MRAR: BDS 4.4
|
|
|
Wind Direction
|
wdir
|
deg
|
EHS: Derived MRAR: BDS 4.4 |
|
|
Temperature
|
temp
|
Kelvin
|
EHS: Derived MRAR: BDS 4.4 |
|
|
Phase
|
phase
|
3, 5, 6, 15
|
Calculated
|
See BUFR detailed phase of flight definition
|
|
Roll Angle
|
ra
|
deg (- left turn)
|
BDS 5.0
|
|
|
Source
|
source
|
-
|
Filename
|
|
|
SIC (Station Identification Code)
|
sic
|
-
|
station ID
|
|
|
Whitelisted
|
wl_flag
|
-
|
Calculated
|
0 = wind and temp whitelisted
1 = wind not whitelisted temp whitelisted
2 = wind whitelisted temp not whitelisted
3 = wind not whitelisted temp not whitelisted
4 = whitelisting not performed
|
|
QC Flag
|
qc_flag
|
-
|
Calculated
|
For now qc_flag = 0
|
Within EMADDC 3.0, the BUFR format remains supported for the time being. However, no further developments, new variables, or structural changes are foreseen for BUFR. Users are therefore strongly encouraged to transition to CSV and/or NetCDF formats, which will be the primary formats moving forward. To facilitate this transition, EMADDC will provide a conversion tool integrated into the KDP download script, allowing users to seamlessly obtain data in alternative formats without requiring direct BUFR downloads.
The EMADDC BUFR format contains the following parameters: dtg, Mid, lat, long, fl, wspd, wdir, temp, phase, consistent with version 1.6. This has been extended with additional descriptors for roll angle quality, source, SIC, wl_flag, and qc_flag. A detailed description of these parameters and their associated descriptors is provided in the table below.
At present, EMADDC distributes only observations that have passed quality control, meaning the qc_flag is currently always set to 0. This behavior may change in future updates as additional data streams are incorporated.
To distinguish between derived Mode-S EHS observations and MRAR observations, two separate file types are provided:
Files are compressed using gzip to reduce bandwidth usage. Please note that FTP distribution will be discontinued with the deprecation of R2.2, and BUFR files in EMADDC 3.0 are available via KDP.
An important distinction is that MRAR data are not quality controlled. These files contain wind and temperature observations exactly as reported by the aircraft and received by ground stations.
The date and time conventions in filenames are consistent with the CSV format:
-
The first timestamp indicates the time of the first observation in the file.
-
The second timestamp indicates the time of the last observation.
-
Observations within files are sorted by date and time (dtg).
In terms of BUFR classification:
To include additional metadata per observation, extra descriptors have been added at the subset level. This approach is necessary because the standard BUFR header does not support all required metadata fields.
To optimize file size, EMADDC uses BUFR subsets, currently limited to a maximum of 100 observations per subset. This limit may be increased in the future to further improve compression efficiency.
The table below contains all descriptors in the WMO AMDAR v7 format that data is written to and the added descriptors as an extension. Hence, the used descriptors are 311010 extended with 25061, 1015, 1022, 1065, 33002. For code tables, see https://library.wmo.int/doc_num.php?explnum_id=4120 and https://confluence.ecmwf.int/display/ECC/WMO%3D33+element+table and is based on Master Table Version 33.
| |
|
|
Description
|
Parameter
|
Units
|
Remark
|
|
0
|
01
|
008
|
Aircraft registration number or other identification
|
Mid
|
|
anonymous mode-s 24-bit id (same Mid assigned to all obs from same aircraft)
|
|
3
|
01
|
011
|
Year, month, day
|
dtg
|
|
|
|
3
|
01
|
013
|
Hour, minute, second
|
dtg
|
|
|
|
3
|
01
|
021
|
Latitude/longitude (high accuracy)
|
lat, lon
|
deg
|
|
|
0
|
07
|
010
|
Flight Level (Pressure Altitude)
|
fl
|
m
|
|
|
0
|
08
|
009
|
Detailed phase of flight
|
phase
|
code
|
intentionally UNSTEADY is not supported by EMADDC as this would remove ASC/DESC information
Steadiness can be read from Aircraft roll angle quality instead
|
|
0
|
11
|
001
|
Wind direction
|
wdir
|
deg
|
wl_flag in associatedField (0, WL; 1, no-WL)
|
|
0
|
11
|
002
|
Wind speed
|
wspd
|
m/s
|
wl_flag in associatedField (0, WL; 1, no-WL)
|
|
0
|
02
|
064
|
Aircraft roll angle quality
|
ra
|
code
|
abs(ra) > 90 → 3, abs(ra) > 5 → 1, else 0
|
|
0
|
12
|
101
|
Temperature/air temperature
|
temp
|
K
|
wl_flag in associatedField (0, WL; 1, no-WL)
|
|
Extension:
|
|
0
|
01
|
015
|
Station or Site Name
|
sic
|
|
|
|
0
|
01
|
022
|
Name of Feature
|
correction
|
|
TBD (unknown)
|
|
0
|
01
|
065
|
ICAO Region Identifier
|
source
|
|
|
|
0
|
33
|
002
|
Quality Information
|
qc_flag
|
|
For now; qc_flag = 0
|
|
0
|
25
|
061
|
Software Version Number
|
version
|
|
TBD
|