ADS-B Update

[Grahame Hutchison]

Since moving to the Eastern Suburbs, my son and I have now setup a network of three ADS-B stations around Sydney, with all the data being combined on 16Right ADS-B.

I have two Stations, one on the Northern Beaches (AirNav Radar Box), one in the Eastern Suburbs (Kinetics SBS-1), and a friend has another Station west of the airport (Kinetics SBS-3). The combined reception polar plot of
the three Stations looks like this.



The reception Polar Plot graph for the Eastern Suburbs Station looks this, and tonight we received a Melbourne to Wellington flight, ANZ850 ZK-OJH, at a range of 600.2 nautical miles (1111.5 km), at FL350. This Station is
using a Kinetics SBS-1 receiver, and my Home Made Coaxial Co-linear antenna, fixed to the inside of a south facing lounge room window. Pretty happy with that result. The best pickup by this station was at a range of 687nm
(1272.3 km). The theoretical maximum reception range for an ADS-B signal is around 230nm, because of the curvature of the earth.

[Philip Argy]

Surprised at the frequency and reliability of tropospheric ducting - the 230nm horizon theoretical maximum rarely seems to be a constraint.

Is this a phenomenon that's common globally, or are there atmospheric conditions around YSSY that make it especially effective?

[Grahame Hutchison]

Hi Philip, The tropospheric Ducting is an atmospheric phenomenon that just comes and goes, depending on weather patterns around the world. If you have a look at the DX Info Centre site for the current forecast, you will see that there is Good to Strong ducting between Australia and New Zealand at the moment (you can select the region of the world at the top of the page)..

From memory, one cause can be hot inland air moving out over the colder ocean, and temperature inversion plays a role as well. I have seen large areas of ducting extending way out to the northeast of Sydney, and east of Brisbane, because of hot air moving out to sea from inland Queensland.

However, the ducting forecast is just like a weather forecast, where nothing is for certain, but it is usually a good guide.

[Philip Argy]

Fascinating stuff - thanks for the reference to William Hepburn's site.

We do seem to have an abnormally favourable set of conditions out in the Tasman Sea, with a quirky little unstable tag around B alls Pyramid from the looks of it!

Then the rain and cloud seems to have all but destroyed it!

P.S. the 'rogue' space is to fool the forum fun police who otherwise will not display the word for the round shape of that pyramidal rock!!

[Danny G]

Thankyou for the new site & all the extras like the usage reports.Very polished creation .Use it most days in preference to the other 2 sites as it concentrates on Sydney. Handy on the laptop when live on site spotting .

[Grahame Hutchison]

Thanks for the positive feedback Danny, my son and I are continuously working to improve our ADS-B site.