Hi John
Good question.
When you have a specific antenna set up, eventually you get to know what you can term as good conditions and what is poor (and what is extraordinary!). Takes time to work it out but you get the jist of things eventually.
And so with AIS Marine traffic, I can now keep track of the specific ships that I hear signals from. Some ships may have a better overall AIS set up than other ships, better antennas, coax, higher antenna position, less obstructions etc. So in that regard, you may work out over time that one ship is easier to get a signal from than others etc.
Then there is the rate of signals, how many position reports you are getting from one ship or another. So say I got 5 reports from Safmarine Meru at the position I did this morning, then another time I may end up getting 20 or 30 over a wider span of area, so I can then say the conditions must be slightly improved to be hearing that many signals.
Being as far as I am from the coast, I can do with some more gain to provide a little more signals through the down times if possible. These will pressumably mainly be off the VK3 coast west of Melbourne, Im hoping to be able pull some signals out of Port Phillip bay Melbourne at some stage, thats what I was aiming for when this one came in from Warrnambool.
The ultimate purpose is to be looking out across the waters of the Great Australian Bight and Indian Ocean to see how far conditions may extend the signals in those good times. Phil VK5AKK has already shown some impressive results with signals about 700 Km west of Perth.
The other thing im now making use of is, every ship or other craft that I receive, Im assigning them to my list of "Fleet" vessels. This is a feature on Marine Traffic.com. So I can click on that link and go and see the vessels I have saved in my Fleet and see there current status and where they are, there itinery, and other details. So when one of them sets sail, I'll know they may be coming back near a position where I have received them before, so I can keep the antenna in a certian direction and have a look for them if I wish to.
So I think summing it up John, even if I had 4 yagis on the system, there is still the ability to know when the conditions are good or bad by looking at the data gained over time, such as distance, number of individual ships, rate of reports received and beam heading. Could be others too but Im only just at the beginning and still learning
Yes, I know, thanks for reminding me
It's getting to be a pain and if I'm not on top of my emails it starts filling up with these stupid emails.
