weerradar

Weerradar is a term used in Dutch-language contexts to refer to weather radar systems that detect and characterize precipitation from a distance. These systems are typically deployed as ground-based installations forming networks that monitor rainfall, storms, and other hydrometeorological phenomena to support weather forecasting, warnings, and hydrological applications.

Most modern weerradars operate as Doppler radars, emitting microwave signals and measuring the returned echoes from raindrops, snowflakes, and hail. The basic observable is radar reflectivity, which correlates with precipitation intensity. Many contemporary networks also use dual-polarization technology, sending both horizontal and vertical waves. This provides additional measurements such as differential reflectivity, differential phase, and cross-correlation, enabling better estimates of precipitation type and size, as well as improved rainfall estimation.

Data products from weerradars include real-time reflectivity maps, velocity fields, and, with advanced systems, quantitative precipitation estimates, storm tracking, and severe weather indicators. These data support weather forecasting, severe weather alerts, aviation safety, flood forecasting, and road weather services. Weerradar networks typically rely on multiple radar sites to cover large regions, with data integrated and quality-controlled by meteorological agencies.

Limitations of weerradar observations include beam attenuation in heavy rain, ground clutter near the radar site, and limited penetration into dense meteorological targets at long ranges. Accuracy decreases with distance, and accurate precipitation estimation often requires calibration with rain gauge measurements and sophisticated data assimilation techniques.

Historically, weather radar technology emerged in the mid-20th century and has evolved toward higher resolution, Doppler sensing, and polarimetric capabilities, becoming a cornerstone of modern meteorology. See also: weather radar, Doppler radar, polarimetric radar.