RADIO ASTRONOMY · FORWARD SCATTER
Watching meteors when the sky is hidden
Radio observations do not need a clear, dark sky. They turn a short-lived ionised trail high in the atmosphere into a signal that can be heard, measured and preserved.
WHY RADIO
A project born from unreliable weather
A clouded-out meteor maximum can mean waiting another year. That frustration started this station: a way to continue observing when optical astronomy is impossible and to retain each event for later inspection.
Earth continuously meets sporadic particles and, at predictable times, denser streams left along cometary orbits. The visible event is brief, but its effect on the upper atmosphere can also be sampled with radio.
THE UPPER ATMOSPHERE
An ionised trail becomes a radio reflector
Meteoroids enter the atmosphere at velocities that can reach about 71 km/s. Most vaporise high above the ground. The hot material and surrounding gas form an ionised trail which can briefly scatter a radio signal far beyond normal line of sight.
At SO8OO the illuminating signal is the French GRAVES space surveillance radar on 143.050 MHz. The transmitter is roughly 1200 km from the receiving station, so the monitored signal normally arrives through reflection rather than a direct terrestrial path.
FROM EXPERIMENT TO ARCHIVE
The station now records continuously
The original 2021 website documented a small manual experiment. The current system uses an SDRplay receiver, a dedicated VHF signal path and an automated recorder. It publishes GRAVES waterfalls and synchronised audio together with receive-only MSK144 periods.
The archive is organised by UTC date and keeps measured observing time, so gaps and receiver downtime remain visible instead of being mistaken for quiet sky.