First Meteor Detections
The evening of Friday 21st June began with the building of an “InnovAntennas” 6 element loop-fed Yagi antenna intended for receiving the reflections from the ionised trails left by meteors entering the Earth’s atmosphere and illuminated by the GRAVES (Grand Réseau Adapté à la Veille Spatiale) space surveillance radar in Dijon, France.
Initial measurements of the antenna matching and noise rejection were made by holding the antenna aloft by hand, pointing it at the convenient source of radio noise provided by the LED lighting in the hut, and later in the evening, the antenna was set up on a makeshift mount tied to the metal barrier surrounding the dome and the coaxial cable feeder brought indoors to the receiver.
Initial tests were made using the GB3VHF amateur radio beacon located in Kent, which both provides a means of aiming the antenna and calibrating our receiving equipment as we develop our system further. This beacon transmits a sequence of reference signals on 144.430 MHz with a GPS-locked frequency accurate to 10-9 (approx. 1 part per billion), one of these is a sequence of tones that can used with software developed by Joe Taylor – a Nobel Astrophysics Laureate, to determine the radio propagation.
We then tuned into the GRAVES radar on 143.050 MHz and were able to receive meteor signals. To help with the analysis and detection, an Android audio spectrum analyser was downloaded and used to create a strip-chart using the mobile phone’s microphone!