The ceilometer CL51 employs a pulsed diode laser LIDAR technology, where short, powerful laser pulses are sent out in a vertical or near-vertical direction. The reflection of light (backscatter) caused by clouds, precipitation or other obscuration is analysed and used to determine the cloud base height, the cloud layer height and the amount of clouds (in octas) in different layers.

Since August 2019, users of the RMI smartphone app are able to send an observation of the meteorological conditions at a certain place and a certain time. The observations provide information about the weather conditions and potentially severe weather to the other users and to RMI. The collection of citizen weather reports is a valuable complement to the information obtained with the classical instruments like stations, radar and satellite. The data can be exploited for nowcasting, warnings and model verification, and eventually in assimilation. A general introduction of the data and their characteristics can be found in Reyniers et al. (2023). A basic quality control is implemented on the received observations via a plausibility check. This plausibility check determines whether an observation is plausible, suspicious or false, by comparing it to the INCA-BE nowcasting system using a simple thresholding scheme. INCA-BE is RMI's operational nowcasting system described in Reyniers et al. (2021). There is no strict spatial extent since there is no restriction at the input side: users can send observations from all over the globe. The bulk of the observations are received from within Belgium. Note that the plausibility check is not available for reports from outside Belgium.

Hail products are derived from the observed vertical profiles of radar reflectivity and the NWP vertical profiles of temperature. Three types of products are generated. poh : probability of hail of any size (larger than 0.5 cm diameter)expressed in %. posh : probability of severe hail(larger than 2cm)expressed in %. mesh : maximum expected size of hailexpressed in mm of hailstone diameter. All products are generated every 5 minutes. This product is not publically available yet.

Geodetic markers of which the 3D coordinates are precisely known in common Belgian reference systems.

Annual temperature extremes given in number of days: 1/ Total number of heatwaves occurring once in 20 years; 2/ Maximum length of the heatwaves occurring once in 20 years; 3/ Hot days: Mean annual number of days with maximum temperature > 25°C; 4/ Tropical days: Mean annual number of days with maximum temperature > 30°C; 5/ Frost days: Mean annual number of days with minimum temperature < 0°C. Heatwaves are defined according to the Royal Meteorological Institute of Belgium when the maximum temperature in Uccle is >= 25°C during at least 5 consecutive days, during which at least 3 days the maximum temperature is >= 30°C. The temperature extremes are available for the present target year 1975, which corresponds to the middle of the 30-year period 1961-1990.

Polar volume reflectivity data from the Wideumont weather radar. Volume data files are produced every 5 minutes from a multiple elevation scan. This product is not publicly available yet.

Inheritances corresponds to the dataset describing declarations of estate and the value of the assets included therein. This dataset is composed of five classes. The first class includes, at the national level, by age group, gender, and type of property, the number of deceased persons, the total value of the property, the median value of the property, the 25th and 75th percentiles of the value of the property, and the standard deviation of the value of the property. The second class includes this information at the level of the three regions. The following classes do the same at the level of provinces, districts, and municipalities. The geographical distribution is based on the deceased's tax domicile. Since January 1, 2015, the FPS Finance is no longer responsible for the estates of deceased persons with a tax domicile in Flanders. Only data for tax domiciles located in the Walloon Region and the Brussels-Capital Region are included in the dataset. The dataset can be downloaded free of charge in zipped CSV format.

Buyers' origin - Real estate companies corresponds to the dataset describing the origin of the buyers (legal persons engaged in real estate activities as defined in section L of the NACE-BEL 2008 nomenclature) of real estate located in Belgium according to the municipality of their headquarters for legal persons settled in Belgium and according to the country or territory of their headquarters for foreign legal persons (headquarter at the date of the deed). This dataset is made up of seven classes. The first class shows, at national level, for each type of property, the total number of parcels, the number of parcels acquired by buyers from each Belgian municipality and the number of parcels acquired by buyers from each country or territory. The number of parcels takes into account the shares actually acquired. The second class shows this information at the level of the three regions. The following classes do the same at the level of provinces, arrondissements, municipalities, land register divisions and statistical sectors. The dataset is freely downloadable, in the form of zipped CSV files.

The composite is produced every 5 minutes using the reflectivity data from the Wideumont and Jabbeke weather radars. This product is not publicly available yet.