Ok, more explanation.
Back in the recesses of the infinite dark past I worked at the BOM in Adelaide for four years going through university. I remembered that balloon launches were typically mid-morning. And also, a few years ago we did a little drive from Adelaide up the Birdsville Track and across to Longreach. Naturally, I visited the BOM outpost there, arriving just before they launched the morning balloon. So we watched that go up, and went inside the hut to see the radiosonde traces coming in in real-time.
So I checked the standard launch times for weather balloons: 2315Z and 1115Z. I figured it was pretty likely that this observation was a weather balloon.
It then occurred to me that, given that satellites, planes etc are all trackable online these days, why not weather balloons?
So I dug around, and found enough sources of data to put the information together.
I found an interesting write up of a rather well-developed balloon tracking project in the radio astronomy group of our SA astronomical society (which I joined a few months ago).
https://www.assa.org.au/resources/ra...loon-tracking/
This explains very clearly how you can build an antenna and a receiver to track balloons and collect data.
It seems that a lot of people do it, hence there is always tracking of weather balloons.
And also software, which I will come back to shortly.
I also found a website for glider pilots that harvests BOM data for weather balloon flights all around Australia.
https://slash.dotat.org/atmos/info.html
Graphical traces for the relevant time here:
http://slash.dotat.org/cgi-bin/atmos...20220606000000
And raw data here:
http://slash.dotat.org/cgi-bin/atmos...20220606000000
These show WSW-ish winds of about 30 knots. A comparatively pleasant day, for last week.
So that alone could give a pretty good idea of where a balloon was heading. One could use the data to calculate a path, but fortunately I discovered that I didn't need to do that.
The above-mentioned ASSA write up includes a link to this site:
tracker.sondehub.org
This tracks hundreds of balloons around the world.
This URL will show the Melbourne Airport site (the leftmost open circle):
https://tracker.sondehub.org/#!mt=Ma...2649,145.72266
This will immediately show any current or recent flights.
But because I was looking for one in the past I had to do a bit more work.
This involved clicking on that circle, and fetching historical data for June, which generates 30 odd dots on the map, representing the finishing points of all flights made so far in June.
So I had to figure out which was the relevant one.
From the glider data above, it wasn't hard to figure out that the finishing point would be somewhere to the east of the airport.
So I tried three or four, and came up with the right one. (There might be an easier way which I haven't found yet, being a beginner with the software.)
A link to the information for that flight is:
https://tracker.sondehub.org/T2250440
With some difficulty, it's possible to click on points on the path shown, to look at time and data at that point.
That's what I did for the picture that I posted yesterday.
Anyway, that was interesting, but the dot by dot search at the end is a minor PITA.
However, the PITA factor arises because I was searching for flights in the past.
The good news is that it is easy to find current flights.
You only have to use the site URL, or the Melbourne URL above, and it will show them immediately.
So that's a good way to check for balloon flights next time something like this happens!
