The BRAMS network comprises a dedicated transmitter and, at the end of 2022, 44 receiving stations in Belgium and neighboring countries.
The reflected signal recorded at a receiving station is called a meteor echo. The reflection of the radio wave is specular, which means that it comes mostly from one point along the meteoroid path, whose position solely depends on the geometry. Hence, different receiving stations will have different reflection points, leading to time delays between the recorded meteor echoes.
Reconstruct accurate trajectory and speed of meteoroids
A long-lasting problem was the ability to reconstruct accurate trajectory and speed of meteoroids using BRAMS data. Indeed, the problem is complex because the BRAMS transmitter emits a continuous wave with no modulation, and hence the distance traveled by the radio wave is unknown.
The only information available are the time delays measured between meteor echoes recorded at various receiving stations. For the first time a method using time delays only has been developed. It provides accurate meteoroid trajectory inclination and speed but is off by a few kilometers in terms of position.
Improved accuracy of reconstruction
A second method using complementary data from the BRAMS interferometer located in Humain improves these accuracies but cannot be applied to the whole BRAMS data set. The accuracy of these reconstructions was assessed by comparing with data from the optical CAMS-BeNeLux network for which BIRA-IASB contributes by running 8 cameras.
These two methods pave the way to fully exploit the capabilities of BRAMS for future applications such as the determination of meteoroid fluxes or sounding of the upper atmosphere (e.g. wind-speed measurements).
Balis, J.; Lamy, H.; Anciaux, M.; Jehin, E. (2022). Reconstructing meteoroid trajectories using forward scatter radio observations and the interferometer from the BRAMS network. , Europlanet Science Congress 2022, Granada, Spain, 18-23 September 2022, Vol. 16, EPSC2022-227, DOI: 10.5194/epsc2022-227.