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.

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.

RMI operates a network of 17 automatic weather stations in Belgium. These weather stations report meteorological paramaters such as air pressure, temperature, relative humidity, precipitation (quantity,duration), wind (speed, gust, direction), sunshine duration, shortwave solar radiation and infrared radiation every 10 minutes.

Top10Vector – Particular zones is the vector dataset of portions of the Belgian territory having a particular attribution which makes them different from the objects in the other Top10Vector-themes. This dataset includes only one class which can be downloaded via the link in 'Access'.

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.

RADCLIM is a historical dataset based on weather radar observations that provides gridded accumulated precipitation composites over Belgium and surrounding regions. The data are distributed in ODIM_H5 version 2.2 format. The reported quantity is accumulated precipitation (ACRR) for 5-minute and 1-hour accumulation periods. UTC is used as the time reference, and the timestamp in the filename corresponds to the end of the accumulation period. The dataset is produced on a 700 × 700 grid with 1 km spatial resolution in the Belgian Lambert 2008 projection (Lambert Conformal Conic).

Bird density profiles are derived from weather radar volume data in real time, by the vol2bird algorithm as described in Dokter et al. (2011, 2019). The vol2bird algorithm exploits the radar reflectivity characteristics of different scatterers in the atmosphere, in order to distinguish biological from non-biological radar echoes. Once biological scatterers are isolated in the volume files, the reflectivity of these scatterers is converted in an estimate of the bird density per vertical layer of 200m, using a mean cross section of 11 cm2. The vbird profiles are provided for the following radars, with the radar owner in parentheses: Jabbeke (RMI), Wideumont (RMI), Helchteren (VMM), Zaventem (Skeyes), Herwijnen (KNMI), Den Helder (KNMI), Neuheilenbach (DWD), Essen (DWD), Abbeville (Météo-France) and Avesnois (Météo-France). References: - Dokter A.M., Liechti F., Stark H., Delobbe L., Tabary P., Holleman I., Bird migration flight altitudes studied by a network of operational weather radars, J. R. Soc. Interface, 8, 30–43, 2011, DOI 10.1098/rsif.2010.0116 - Dokter A.M., Desmet P., Spaaks J.H., van Hoey S., Veen L., Verlinden L., Nilsson C., Haase G., Leijnse H., Farnsworth A., Bouten W., Shamoun-Baranes J., bioRad: biological analysis and visualization of weather radar data, Ecography, 42, 852-860, 2019, DOI 10.1111/ecog.04028

UV Index derived from spectral measurements with a Brewer UV spectrophotometer. This product is not publically available yet.

Administrative units - current situation corresponds to the dataset of administrative units from the reference database for the land register data. Administrative limits are legally defined by an administrative entity or between two administrative entities. In Belgium, administrative limits as legally defined are fixed and can only be changed by a law, ordinance or decree. The General Administration of Patrimonial Documentation of the FPS Finance is named by the federal authorities as the authentic source of Belgian administrative limits. This dataset corresponds to the current situation at the time of consultation. It is composed of five geometric classes. The first class corresponds to the whole national territory. The second corresponds to the territory of the three regions, the third to the territory of the provinces, the fourth to the territory of the administrative districts, the fifth to the territory of the municipalities. The dataset is freely downloadable via the ad hoc WFS service.