A slightly later post as I am still repairing my chair after falling out of it.
First Dog on the Moon is fast becoming the go topl;ace for all the news and views on World affairs. Well, not really but he does show how barking mad many of our politicians see to be and the rest worship at the alter of Mammon. We need a change and we need to change.
Checking the 3cm band this morning just before sunrise and I was surprised at the absence of signals. Only GB3PKT was present, much stronger than usual when pointing towards PI7ALK. Nothing else, nada, rien, gar nichts.
Not even anything from GB3LEX, F5ZTR or ON beacons. Zilch, nix. That is the wonder of having very few aircraft flying about.
Checking the wave height in the North Sea showed that it is around 2m across the main body of water, less nearer the coast and of course zero after the waves break onto the shore. We can be confident then that an evaporation duct is unlikely to exist across the the European mainland.
PI7ALK was a very strong signal s7 or so and quite stable until about 2200utc where it started to become much less stable, fade out seems to have been complete by about 2300utc. This is supported by the signal history of GB3PKT which shadowed that of the Alkmaar beacon. Minimum signal appeares to have been reached at around 22.00utc (-18dBjt) but recovered at 0054utc (-14dBjt)
The signal from GB3PKT is affected by coastal and tidal effects, an investigation I was hoping to conduct by comparing signals with GB3MHZ. Sadly the Martlesham beacon is showing a reluctance to radiate a signal. A short time ago I could hear it, sometimes direct, and more often from wind turbine scatter. The last ten days or so I have heard/seen nothing from it. Maybe it too has gone into self-isolation, hidden itself from the public. Maybe sometime in the near future a baby beacon will appear.
Back to radio… No signals from the usual beacons. Looking closely at the waterfall I see nothing via troposcatter either, no weak smudges, even at different small increments of elevation. It is at this point the usual first move is to check that the system is working. The pigeon sitting on the feed tells me that all seems to be normal as the noise level increased when it sat there and reduced when I persuaded it to fly away.
It is at this point I toss in the throw away line “beautiful sunrise this morning, incredibly clear air. Really crisp and clean with little or no haze.”
I could go on but therein lies the clue to the fact that there are no signals to be heard. Clear air….little haze…
Water vapour content is low and this is confirmed by looking at the Eumetsat Fog sensor image. It clearly shows a widespread lack across the UK and near European mainland and therefore troposcatter will be very weak or nonexistent.
There you have it. An interesting start to the day as it serves as a reminder that signal monitoring at microwaves has a number of surprises. Nature sends a little message as a reminder that it is all well to pontificate on reflection geometries, wave heights, refraction indices and so on. Ultimately she is in charge and will determine the course of the investigations. I need to find reliable measurements of WVC , or humidty (humility?). These figures may be available in the dataset from Eumetsat/AVIS. A clue may also be in the Skew-T charts that show sharp and deep changes to Dew point tempertaures for Helgoland, Brussels, Essen, Frankfurt, London and Manchester. Typically -30 (or -40 deg C) at 600hPa (approx 4000m)
Just look at the orange peel like cloud formation over France at 0700utc.Wow, just wow.
Note:
* unfortunately this applies to the UK Government’s actions to manage the COVID-19 pandemic. The UK Government has gone to great lengths to demonstrate that nothing is too much trouble. I salute our medical and frontline workers for their tireless devotion to our wellbeing.