Affect of reception due to weather.

[sherlock holmes]

Hi,
I don't remember seeing comments on this subject. Does the weather have a great affect on reception? I have recently acquired a new DPD antenna and it has increased my range and number of flights in My flight log. We are unfortunately in a weather pattern of 7 days of overcast and daily rainfall of approx .5" of rain a day. If the sun ever comes out again here in central Ma, do you think the range will be extended further?

Thanks
Sherlock Holmes

[imropes]

A strong high pressure can increase pick up range have a look at the tropospheric ducting forcast website. Its rarely strong over the North of England but i have freak pickups from time to time.

[sherlock holmes]

Hi Imropes,
I will check out the website. I would give anything for a high right now. We're looking for some improvement next week.

Thanks

[Peter]

Weather has a great influence on VHF propagation and AIS conditions vary from flat at around 30 - 40 miles to possibly 100's of miles during an inversion. I'm situated in East Anglia, around 10 miles inland and especially at this time of year, have received shipping around to the Solent, or off the coast of Denmark depending which way the duct is running. You need a nice warm day, cooling off rapidly in the evening and an inversion may take place. It decays rapidly without warning, and you are back to square one! Likewise, early morning 0700 - around 0900hrs is another likely time. You can get early warning by listening to say Volmet on the VHF airband. There are 3 different frequencies, normally I can only pick up a scratchy signal from one on my scanner with the squelch fully opened! A couple of weeks ago I picked up a solid signal from all 3 at around 2100hrs. That is my prompt to watch and listen out for anything outside my usual range!

Peter

[tarbat]

Good reception conditions at the moment.  Using the ShipTrax beta hardware and software with a loft-mounted discone, I've been getting some ship returns >60nm away.

[imropes]

Take a look at Thursdays predicted Tropo chart. If correct ideal time for elementry Sherlock to check out his DPD.

[Peter]

VHF lift developing as I type, my range from East Anglia is now 90 miles, the track appears to be laying Eatward across the North Sea. Distance noted from AIS dispatcher 1.3 and verified by plottings of "unknown" vessels on my maps.

Peter

[Peter]

Back to normal 30 miles by 1300hrs

Peter

[jannuh]

Tropo Duct Forecasts:
http://www.dxinfocentre.com/tropo_nwe.html