AIS Marine Traffic Tracking (tropo indicator)

[VK2KRR]

Sinisa,

Its about 330m higher than the house. Virtually like having a 330m tall tower as it shoots almost straight up from the surrounding ground. But from all the tests I have done I find the hill to be too high. If I lived closer to the bay at Melbourne at the hill top was line of sight it would be good. But I find that as its a lot further out than that, that to make good use of the troposphere I need to be down low, underneath the inversion layers, where as I think the hill is too high and above most surface ducting. So when the signals get trapped and ducted up here its actually better to be at the house rather than up the hill. Which works out good for me as I can base everything from home.

Excellent regarding the very long distances that are possible there, at least thats something extra for you to look forward to and a good challenge to try for.
We have not had a real good summer tropo season here, so I hope you have some more luck than we did.

I've saved your stats page and will keep an eye on it occasionally to see whats happening there.

[VK2KRR]

Evening.
Found that currently Marine Tracking station 302 near Bairnsdale is hearing a ship on tropo over the NZ side of the Tasman. So a heads up on some possible conditions. Will be keeping an eye on progress.

[VK2KRR]

3 stations now getting 2 x ships in this general area of the ocean toward NZ.
302 near Bairnsdale
695 Port Albert
333 on the coast from Launceston.

Distance is in the area of 1500 Km.

[VK2KRR]

Now the ship is also being logged with VK7JH at Burnie, 1611 Km east.

[VK2KRR]

Last night after the weather change I pointed my marine antennas west for the night and today.
Was surprised when I got up to find I had a spot at 1637 Km. This was from ship Safmarine Makutu, virtually in the middle of the Bight.
Later in the morning I also got a spot from Taminya, located just near Whyalla @ 904 Km.
I believe both of these would have been received via a meteor burst rather than tropo as there was only 1 signal from each. Interesting to see none the less.

VK2KRR

The others you can see are tropo. The one sth of Warrnambool was right infront of the cold front.

[VK2KRR]

Phil VK5AKK and myself have both noticed some out of the ordinary tropo spots just ahead of cold fronts as they move across from west to east if we are closely inline with the signal path along the frontal line.
Ive just noticed this evening a quite good example of this, with station 932 VK2HIM near Wollongong now hearing signals from a Japanese ship 965 Km south of his QTH, ahead of the frontal movement.

[VK2KRR]

A rare (at this point in time) tropo opening other than Melbourne way this evening! As the fronts came past, even though Hepburn shows nothing, its a good idea to look in a westerly direction in the early part of the new high cell. Was nothing all day but I just was turning the antenna about this evening and came across a small opening to the SW from here. Between around Portland and Mt Gambier. 4 ships all up and 366 signals. It seems to have stopped now.

[ZL1TPH]

[quote="VK2KRR"]Phil VK5AKK and myself have both noticed some out of the ordinary tropo spots just ahead of cold fronts as they move across from west to east if we are closely inline with the signal path along the frontal line.
Ive just noticed this evening a quite good example of this, with station 932 VK2HIM near Wollongong now hearing signals from a Japanese ship 965 Km south of his QTH, ahead of the frontal movement.

Hi Leigh,

From my observation this could be considered normal. It what's called the trailing edge of an anti cyclone(or high). In your weather map (two postings above) you will see the high, or what remains of it, still sitting across the Tasman sea and that frontal line as you mentioned is blending the mix for tropo. Both of these are the key - or more than likely there would be no temperature inversion at all.

Attached below is a weather map back in 2009. (Contacts to VK on 144, 432, 1296) It gives another example. Look for two things, the high is moving away and the red line denotes the path or trailing edge of the anti-cyclone. But for the duct or inversion layer to form, requires that cold front also to blend the mix.

PS wont be long (by the looks of it) for a ship in ZL to get spotted in VK. Keep up the good work ...

Cheers, 73 - Steve ZL1TPH

[VK4AJL]

ais 23 apr.pdf

(289.09 KiB) Downloaded 446 times

Should be good tropo to-day 23 vk4 here is a screen dump 14.30 utc from Mackay

[9A4CU]

Really nice tropo there.Hope to see something like that towards PNG.

[VK2KRR]

Here is Georges tropo image he was trying to post without success.

VK4AJL Mackay

George mentions these were his best distances for quite a while.

[9A4CU]

Pretty good tropo at 05.46 UTC along VK6 coast.This is received by Alek,VK6APK.

[VK2KRR]

Its been a while in the making, but welcome back to Tim VK3JTM near Ararat. Now running Marine Traffic Receive Station 1123 as of last weekend.
http://www.marinetraffic.com/ais/statio ... on_id=1123

Although Tim is still sorting the set up out, some positive results overnight with a couple of decodes off the coast between Warrnambool and Otways as pictured. (the signals came from within the area of the marked blue squares)

VK3JTM

Tim is running an interesting receive unit which does a lot of different things in the one box I think, such as ship and plane plotting from the one box. Tim may explain it a bit more, im not familiar with it myself.

[VK2KRR]

Just FYI.
At times you may see me post statistical numbers on the chat page, such as 2600/32. Unless your regularly watching on the logger you wont know what that is. Well here is an explanation and how it can be of use to some stations.
The example - 2600/32, refers to 2600 individual signals from 32 individual vessels. This could be any number depending on the conditions and starts off at 0/0 at around 5pm each day.
I reset my marine tracking stat counters every day at 5pm or a bit after, as this is usually about the time of day here where the tropospheric conditions are at their worst. Most action begins after sundown, through the night and early morning. So hence I start the new counting period from about 5pm. It then takes in a full night and day.
So, here is an example screen shot -

Marine stats reporting

In this shot you can see a few of the posts im talking about.
At -
0237 utc - 2230/32
0302 utc - 2310/32
0321 utc - 2401/32
0359 utc - 2503/32

From these stats you can get an idea of how good the conditions are in the Melbourne directions from here. Most times I will report stats at each 100 signals received or there abouts. So if you look at how quickly the stats are increasing between 100 sig reports you know how good or bad things are.
So in the example we have taken approx 25 mins for the first 100 increment. Next has taken shorter 19 mins, and next around 38 mins. The shorter the period between 100 reports the more intense the conditions are becoming. Below 10 mins per 100 things are really hopping. If condx are exceptional I will switch to reporting every 500 sigs.
Also in the above example, the total number of vessels was 32 and didn't change over the example period. Obviously the more vessels, also the better the conditions, but will mainly go off the total signal numbers as the one to watch.

I record the total daily stats here http://www.vk2krr.com/ais_marine_162_mhz_dx.htm this is updated every day or so.

[VK5ACY]

Good stuff Leigh.

I, for one, always look at your statistics posts and consider these to be 'valid' VK Logger posts as
they are an indicator of tropo conditions.

Bill VK5ACY
PF95sb
.

[VK2KRR]

Thanks Bill

Basically they are like a floating beacon signal, showing information about paths that we would otherwise not know about as all of our beacons are on land.

[VK2KRR]

Last night I was fortunate enough to get my first marine signals via tropo to the west since I've been set up, back around the start of this year.
Hepburn charts showed promise and, some subsequent tests with the marine yagis plugged into the IC910 showed weak signals from Murray Bridge, Crafers and Barossa Valley 2m repeaters (760Km+-). Could also hear FM carrier weak from Phil VK5AKK on 2m. The Mt Gamber 23cm beacon was very audible. This looked promising.

A listen to the marine tracking freq's with headphones on had weak pulses coming in, just need enough signal to decode.
Eventually between about 1300 & 1400 utc signals were decoded out to about 845 Km Was hopeing it may have gone further but that was as good as it got for this night. Hope to hear some more tonight.
Attached is the map showing the blue squares just west of Adelaide where the signals were heard from. Also the signals in the Melb area were heard prior to last night, Melb path was not good while the path to Adelaide existed.

Adelaide MTS

[VK2KRR]

This is a different view from last nights Marine Traffic page with my callsign showing up as being the data source for one of these vessels (both eventually). Was pretty pleased to see that up there

One of the first western spots

[VK2KRR]

My best opening yet occurred in the evening of the 8th of June, across to the waters of the St Vincent Gulf, between Adelaide and Yorke Penninsula.
The max distance was 867 Km from the 12 Watt Marine tracking signals. There was 7 vessels heard over here and numerous signals, in excess of 200, maybe 300 but I didn't fully count at the time, but there was quite a few. The best time appeared to be between approx 11pm and midnight.

867 Km Tropo

[VK2KRR]

Starting to see a well formed graph on Phil VK5AKK's AIS stats page http://www.marinetraffic.com/ais/statio ... ion_id=146

Gives a good representation of the rise and fall in distances as the seasons change from Phils QTH. The graph is Distance in Sq Km by day. I have added a a trend line in there also. Here it is here -

VK5AKK AIS Graph

The initial distances through Oct, Nov may be lower than expected as Phil was still experimenting with different antennas at that stage.