From York, using forward scatter signals off the BRAMS beacon (49.970MHz), I observed the Geminids over the 24h period 191214 0000 – 2359UT (and for a few hours either side on December 13 & 15). I attach charts of events and durations for December 14. A total of 1756 events were logged although my configuration of Spectrum Lab definitely under-reports the fainter meteors. I have yet to work out what percentage of events is missed.
The events chart is arranged as a histogram in bins of 10m. In general terms the pattern seems to represent an enhancement or amplification of the normal diurnal curve – there are no clear peaks. This suggests to me that the meteor flux was consistently raised over the period that the radiant was above the horizon (about 1800 – 1100 UT). I would welcome the comments of others on this. After about 1100 UT the curve, such as it is, returns to the usual sporadic numbers until the radiant rises once again at about 1800 UT.
The chart of durations is more interesting. Here there is a discrete episode of significantly longer echoes between 0930 – 1100 UT: in other words, just as the radiant approaches the western horizon. If this really does represent a filament of denser or larger particles then the filament was around 162000 km across at that point. There are similar, smaller, but still identifiable episodes at around 0230 (transit), 0750, and 1830 (radiant rising in east).
Thank you. On and off about five years. But only a couple of months using BRAMS and my Icom R75 – which by the way I now prefer to GRAVES and the Fun Cube Dongle! I do intend to look back over my old data and if I find anything comparable will post it.