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.

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

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.

RADQPE provides high resolution radar-based quantitative precipitation estimation in realtime for Belgium and its surroundings. This product is not publically available yet.

Hourly forecasts for each belgian commune, from current hour up to the next 5 days. This product is not publically available.

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).

Download Service (WFS) for Networks of automatic lidar-ceilometer systems The data are updated each 10 minutes. Only the archives of the last 30 days are available.

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.

From multiple observations during the day with UV spectrophotometers a daily value of the ozone column is calculated. This product is not publically available yet.