Mapping and tracking meteoroid streams with a 20-year European meteor radar network

Meteoroid streams and their associated meteor showers provide useful constraints on the small-body and dust environment near Earth, but many weak, high-latitude, and daytime showers are still not well documented. We introduce a framework to use almost two decades of observations from six European VHF meteor radars—Collm (Germany), Tromsø, Alta and Svalbard (Norway), Esrange/Kiruna (Sweden), and Sodankylä (Finland)—to map, track, and classify meteoroid streams in a consistent way. Starting from monostatic echo detections that provide location and velocity information, we combine thousands of individual meteors into daily radiant intensity maps in ecliptic coordinates as a function of solar longitude. For each radar, we then construct composite radiant maps with 1° resolution in solar longitude, yielding 360 maps per composite year. Image-processing methods (background removal, local-maximum detection, and clustering in both (λ, β) and sun-centred (λ−λ_⊙, β) coordinates) are applied to automatically identify candidate shower radiants and to follow their motion with solar longitude. A simple tracking algorithm connects radiants between consecutive solar-longitude slices and produces radiant tracks that can be compared with IAU shower lists and video-network solutions for stream identification and preliminary source attribution. In this contribution we will describe the methodology, show initial examples of radiant maps and tracked streams, and discuss how radar-based statistics of meteor radiants from these six stations can be combined with optical observations and meteoroid-stream modelling to improve our picture of the near-Earth meteoroid environment.